Image limit reached >>2996880>I'm new to electronics. Where to get started?It is an art/science of applying principles to requirements.Find problem, learn principles, design and verify solution, build, test, post results, repeat.Read the datasheet.>Comprehensive list of electronics resources:https://github.com/kitspace/awesome-electronics>Project ideas:https://hackaday.iohttps://instructables.com/tag/type-id/category-technology/https://adafruit.comhttps://makezine.com/category/electronics/>Books:https://libgen.is/>Principles (by increasing skill level):Mims III, Getting Started in ElectronicsGeier, How to Diagnose & Fix Everything ElectronicKybett & Boysen, All New Electronics Self-Teaching GuideScherz & Monk, Practical Electronics for InventorsHorowitz and Hill, The Art of Electronics>Recommended software tools:KiCAD 6+CircuitmakerLogisim Evolution>Recommended Components/equipment:OctopartLCSCeBay/AliExpress sellers, for component assortments/sample kits (caveat emptor)Local independent electronics distributorsladyada.net/library/procure/hobbyist.html>Most relevant YouTube channels:EEVblogW2AEWMoritz Klein>microcontroller specific problems?>>>/diy/mcg>I have junk, what do?Can it run Doom?>consumer product support or PC building?>>>/g/>household/premises wiring?More rules-driven than engineering, try /qtddtot/ or sparky general first>antigravity and/or overunity?The doctor prescribes .45 ACP brand aspirin STAT.
>>3002473I picked up a Sony KV-9400 TV. Picture from Reddit but mine is exactly the same. I'd like to use it for old computers and video games but the picture quality has issues. It does not have a plain RF jack or composite inputs. I have to use a UHF/VHF matching transformer and then an RF modulator for the original device. Something along the line is causing interference as I get a bit of snow in the picture. How can I improve the quality? Is there a way to ditch the matching transformer? Or shield everything? Or add composite inputs directly to the TV (not an RCA to coax converter box)?
>>3002460WINRAR!Luckiest fucker around award. Well... other than having to try so many. But this might be IT, the ONE single fault. No Vcc on the IGBT driver - > no output.16V 220uF. Dead short.
>>3002479Awww dang. I hardly ever buy electrolytics because they can suck my dick. But what to put in there now. Got some fresh 1000uF 16V, shouldnt hurt on just Vcc to GND. Got a bunch of used ones. Could fuck alot of films on there.Since we can't make 16V films, why dont we just put a kV film on a transformer. Im sort of a genius you know.
>>3002481I'm not convinced it's needed. Don't ask me why it died. But there's nothing nearby that warrants this. A 5k R going to a switch or knob on control panel. S8050 collector, emitter is on a 1.3k R. The one 4093 is already closer to the large cap next to the reg and frankly idk why anyone would put the cap there, it's not bypassing shit.
>>3002476I’d try shielding and clip-on chokes, but if anything I’d want to go for VGA. The TV is converting a composite signal into RGB components and audio and sync signals anyhow so there’s no real reason to settle for an inferior composite input. But adding component or VGA inputs is likely more invasive than adding composite input.
>>3002501Wait, TVs from 45 years ago can have RGB input?
>>3002505I don’t see why such a mod wouldn’t be possible. The RF input gets demodulated into composite video, which gets split into amplitude and a chrominance signal, which then gets demodulated into red green and blue signals, which then get amplified and sent to the electron tubes. The more superfluous steps you can eliminate, the better the fidelity.SCART is an RGB video input and was in use since 1978.
>>3002490I sort of rigged it. I'm relying on my belief that the thing just clocks through and has little faukt and error checking. I disconnected the EMI module and connected only the auxiliary transformer. The power section isn't getting mains, the pulse transformer stage is still on the bench, I am just hoping the machine cant tell and I will get gate drive for every power transistor. Also curious to poke around a little once it's going.Fingers crossed for the smoke to stay in and signals to be there.Swapped a new 1000uF 16V cap in there as it's just bulk capacitance, unlikely to cause issues.
>>3002524It came on, some relays click on startup, idk what LEDs on logic board mean, some green ones one red one on others off, I'm sure some are clearly there to indicate gate drive. Warning light on front panel is on. The 555 on repaired board is ticking away happily at the set AC frequency and the AC DC relay clicks with the switch. Odly the stick TIG switch doesnt overwrite it as I've expected. Adjustments to currents and all that are reproduced by the segment display. No gate drive anywhere but I think in case of the pulse transformer it might be that the feedback loop is just maxed out or it comes on on demand only. Logic board is doing suprisingly little. Suprising because the general strategy for almost everything seems to be to have a timer running and the timer gets connected on demand instead of starting to run on demand. I would have expected a generator for the switching frequencies but perhaps its all current loops with no fixed frequency. I'll rig a switch to fake the torch but I suspect the boars does a bit more error handling than I hoped.
>>3002515I did some checking on this TV. Schematics are available. Picture related. It is a hot chassis. Everything is AC. This guy would have to use some kind of optical isolator to add any kind of new input to the system or the grounds on that input would be live 120 volts AC. Heck, they say to use an isolation transformer to even work on the thing while it is plugged in.It also uses some tiny jungle chips and I can't find a datasheets for most of them. CX556 has a tiny, shitty pinout available. It appears to be an NEC uPC1352C chip. Pins 26-28 are RGB out but there is no RGB in. It does have luma (5), chroma (13), and blanking (24) inputs though. And 'Demo input' (25), whatever that is. The only RGB mods I have done always tap into the RGB inputs on the jungle chip.This would be a hard row to hoe for someone that hasn't do this kind of stuff before and he's just asking how to get rid of snow over RF. Heck, how would he even get RGB out of old consoles and computers? AFAIK things like the 8-bit consoles were all RF or composite. 8-bit computers like Atari's and Commodore's only did Chroma/Luma at best.
>>3002530Yeah I never said it would be easy. As for the RGB source, VGA. You’d also need to handle the sync signals.
>>3002529The temperature switch from the power board fixed the warning light, duh.Found a 555 that reacts to the pulse frequency. The pulse width pot is routed close to it too. Just like the up and down slope settings. I know there's analog switches. I have a theory where the analog switches multiplex through the adjustment pots accordingly to the phase of the process the machine is in. This would make sense, slopes aren't pulses so they probably have a S-trigger that is equally multiplexed in, so they can make slopes into pulses but I can see why one would one source for all the envelope timing stuff and just swap out the resistor for the RC element and maybe slam the reset on the 555.The machine now wants to gate drive the first pulse transformer stage. The green LEDs faintly agree. But I can't make much sense of the driver. The cap close. to the two TO-220, IRF640N is charged to 15V. The trabsformer puts out a signal for the base of those TO-92 half bridges. The base drive signal and only that appears on the output, the small caps feeding the half bridges are not getting charged. I suspect the voltage for the gate drive does somehow come from the board with the transistors on it. On the power board the gates are merely pulled to source via resistors. Idk, more tomorrow.
>>3002532Computer VGA is not the same RGB as TV RGB. RGBhv versus RGBs. You've need a converter even then. Besides, who would want to output VGA to a 9 inch screen when CRT computer monitors are easier to acquire than CRT TVs? 9 inch was fine for 8-bit machines but I wouldn't want to use it for something natively outputting 640x480.
>>3002534Errr maybe not tomorrow.Seems to work. Shorting the switch input gave HF start, lots of relay clicky action, gas valve and all that.Throwing it back together completely.
>>3002540>Computer VGA is not the same RGB as TV RGBthere's also the non-trivial problem of HSYNC frequencycomputers are around 31Khz but TVs are 15Khzso you get this rolling double image shituation
>>3002476>matching transformerAlso called a Balun. Do you even need one of those when you aren't using an antenna? I don't know. If you can eliminate that you might get better picture quality.
>>3002603A balun is not a matching transformer. A balun converts a balanced to an unbalanced signal or vica versa. A matchibg transformer can literally be an unun.
>>3002603Your pic and my pic make a good team.
>>3002608For TVs a balun is a matching transformer. Google it. Shit man, Wikipedia even redirects matching transformer to Balun. Am a saying all matching transformers are baluns and all baluns are matching transformers? No. In this specific case though, it is correct. Now, do you still need one to connect an old TV and an Atari 2600? Fuck if I know.>>3002611I actually had one of those growing up. Probably still on one of my TVs somewhere.
>>3002619>Now, do you still need one to connect an old TV and an Atari 2600? Fuck if I know.If the TV already has an F-type coaxial connector input then you just need to adapt RCA to F-type. If the TV only has antenna terminals, you need the matching transformer and female RCA to male F-type adapter.
>>3002621This is assuming the Atari is outputting a RF signal and hasn't been modded for composite output.
>>3002619You're not getting my point.You explained that 'a matching transformer is also called a balun'.This is incorrect. A balun can be 1:1 and in this case will not provide impedance transformation. Equally a matching transformer can be a simple unun and in this case not change symmetric to unbalanced. Baluns can be matching transformers, balun and impedance transformation. But this doesn't mean that all baluns are transformers or that all matching transformers are baluns.
>>3002619>Am a saying all matching transformers are baluns and all baluns are matching transformers? No. In this specific case though, it is correct.>>3002646>But this doesn't mean that all baluns are transformers or that all matching transformers are baluns.>You're not getting my point.And you aren't reading my post. I posed it again to give you a second chance. Don't make me have to post it a third time.
>>3002655>second chanceKEKImbecile. You're correct that I did not read it as you even started it with repeating the same statement. After you had a chance to realise your error. Meanwhile your argument boils down to 'links between wiki entries'.And now you go on about 'chances' because for some reason you keep insisting that either you didnt say or mean what you did or you were correct and matching transformers are baluns or vice versa.Retard.
>>3002657>You're correctApology accepted.>>3002476>ditch the matching transformerNah, seems you are stuck with it.>add composite inputsNot without seriously modding the thing. Which you should not attempt with a hot chassis. Maybe circle back on it if you ever get into modding and get more experience under your belt.You could try broadcasting your own TV channel. Basically, all you need is something with RF out (like a console), an RF amplifier, and an antenna. Console RF out > amp > antenna. Turn the TV to the channel the console is outputting to and it should work. This requires no modding of anything, lets you output to multiple analog TVs, and won't get your electrocuted (RF burns are a different thing).
>>3002530I’m not sure what’s going on with the mod/ext switch, looks like there might be some sort of balun already in there, but I can’t tell if it does any impedance matching. That UHF input is definitely 300 ohms balanced, but the VHF input to the demodulator chip looks to be coaxial. There’s three VHF wires going to connectors, but I only see two screw terminals for VHF in the image >>3002476? The switch seems to be designed to let the user connect a rod antenna, if it’s a quarter wave antenna it would be an unbalanced 36.5 ohms, since it’s not 75 and has no shield you’d probably want to go for a 300 ohm input instead.You’d probably want to go through that transformer either way to isolate yourself from any hot chassis, but idk about that stuff.Also one of those balun windings looks shorted.>>3002555Oh, and you can’t change that in the computer video settings? It’s still an option to use an HDMI to RGB-component or SCART converter, with the right level shifting or amplification or whatever to tap in after that big IC in the top right corner, if you wanted to maximise video quality. But with that and the high voltages, it’s an advanced project I wouldn’t recommend to anyone who hasn’t done simpler CRT mods.>>3002657>>3002674Quit polluting this space with your failure to communicate. It’s obvious that the first anon meant:“All external television baluns (the only type of balun relevant to this discussion) are 300 to 75 ohm matching transformers, and so a person looking into TV matching transformers should use the more common name of TV balun”.
>>3002683If you would like better quality images of the schematics you can get them here:https://archive.org/details/manual_KV9400_SM_SONY_EN/Due to resolution and file size restrictions on this board I had to halve the image size. Nice to see hand drawn PCB layouts every once in a while, eh?Here are some videos of the TV opened up and in action:https://youtu.be/KwrXDv9wYZ4https://youtu.be/mdBcdy3S_T4?t=245https://youtu.be/LXaYUPCCn0o?t=45In the first two videos is does appear that they are using baluns on the VHF terminals. If one is build-in, would using a second one the cause the snow problem >>3002476 is having? Shame I can't find an operators manual for it as that might cover that.
>>3002700>If one is build-in, would using a second one the cause the snow problem >>3002476 is having?I suspect not. I'd try both VHF and UHF since there's definitely a difference in circuitry between those, but those balun cores shouldn't make a significant difference to quality.>VHF: 75 ohm unbalancedOdd. If there was a shield connection to connect a coax up to the internal unbalanced VHF input I'd definitely try that, but there isn't.
>>3002700>it does appearyou mean at 8:30 in the first video? The fun bit is that I expect the device to flip it the other way round again almost first thing after the input. What's the TV gonna do with a balanced signal?So yeah at 8:30 that guy uses one almost certainly, unless hes up to really weird shit, he's using an unsymmetric like of god knows what impedance to connect to the symmetric piece of line and inputs after all. So unless weird quirky eqceptions apply here that's definately the case. Sorry, know all about transmission lines and HF but nill about TVs other than cathode ray, funny magnet coils, reset on sync and advance by 1 scanline.
are rolling op amps a meme? shit all sounds the same to me
>>3002789I have no idea what 'rolling' here means but judging by the obvious audiophile context:Yes. Most likely.No field is more of a scam or delusion than audiophile BS.If you want good audio designs stick to the basics and if the water is murky, check if it's something that is relevant to HF and radio communication.You see, if systems that are sensitive to - 130 dB, are governed by very tight channel separation rules and so on work without salting your transistors under the full moon - then it's probably not needed. Meanwhile established and well proven methods to make amplifiers linear asf exist. Idk go digital and predistort your signal or go analog and severely degrade your active element.>inb4 but digital some HF component blablaBesides humans being unable to perceive frequencies much higher than audio it's not even reasonable those signals are being reproduced, perhaps wont even ever reach a speaker because of intentional and unintentional LP filtering and the speaker - who knew - is a LP filter on its own again, just like an ear.Sorry. But audiophile ideas are exhausting.
>>3002792rolling means swappable in this context. I'm curious if switching out the op amps from a NE5532 will do anything whatsoever
I want someone to point me at a video, book, or any other source that explains how to build a mist generator with those ultrasonic speakers.I don't need a source that tells me>here are the components>solder them and violin, mistI need to learn the theory.From what I see you need to do something like impedance matching in order to drive the speaker efficienty so as not to waste energy.Is there any source on that?
>>3002789>>3002800There definitely are some differences between op-amps when they're pushed to their extremes (mainly slew-rate and hard-clipping) but generally the whole point of an op-amp is that it's acting like an ideal component. Another difference you may notice is noise floor, if you're amplifying by a lot of dB or otherwise have a very quiet signal, bad PSRR and CMRR figures can make noise audible, especially if you're trying to maintain 24-32 bits of dynamic range. Square root hertz noise may matter here too. Standard listening doesn't get anywhere near 32 bits, but some fancy microphones record at 32 bits to avoid any clipping distortion, allowing for editing of levels in post. You should primarily aim for low power rail noise and common-mode noise in the first place, but the ripple rejection of your op-amps still make for an important step in your noise budget.I usually use socketed op-amps in my circuits because I'm often pushing them to their limits, with high-ish gains and frequencies where oscillation is a possibility. Also where blowing shit up is a possibility, and I'd prefer to easily be able to swap out my silicon chips. I'm not making hifi circuits.>>3002805Ultimately they're capacitive piezo elements, so you might have better luck searching how ultrasonic cutters or cleaners or antifouling systems are driven. From what I understand you can either pick a fixed frequency, or make a circuit that finds its own resonant frequency. Some piezo elements have their own feedback pad that make this easier, though I've never seen that on a mister. You couldn't make an LC tank circuit with the piezo element as the resonance frequencies would differ, but when driven at its mechanical resonance point I imagine the power factor changes enough that you could use current feedback from a square-wave voltage driver. Something like pic related. Modelling the piezo disc in spice seems like a massive pain so I'd just start breadboarding.
>>3002811thanks, good to know
>>3002811>slew rate>clippingin audio designs>noise floorwith your ears, even after amplificationI will gladly sell you resistors that violate the sqrt(4kbTRdf) for some audio designs KEK>CMRR makes noise audibleyou mean passes existing noise through.>microphones record at a resolutionthey just convert physical phenomena, a digitizer that may be downstream would have finite resolution and so on. Audiophiles have alot in common with amateur radio.>not making HiFi circuitsthank god but still: None of this applies to human audible perception or at all to a sensible design for audio frequencies.>Piezo transducer frequency.They will faithfully reproduce any oscillation within their specified limits. Usually (ultrasonic cleaners and such) one gets to see suprisingly high voltage drivers operating at fixed frequency which very likely happens to be equal to the datasheet resonant frequency of the element.
>>3002534Sort of rigged it back up together after believing I had identified and rectified the one single issue. I have added probes to the output of the first power stage, so between the rails of the split power supply that is the output.>picrel I am probing like thisI am getting normal operation from seemingly everything. LEDs on the gate driver on one side show it's active. This means the thing is operating as a two switch forward. I am getting less than a Volt on the output. I believe if everything works I should register idle voltage, which is quite high, there.Obvious issues?
>>3002838So I checked gates on the first stage next. Seems to be okay. It looks like the operating frequency is set at 25 khz. Pulses are ~1us wide but there isn't a load and I turned the current setpoint way down.I'm getting noise on the gates of transistors that should be off at 500 khz, 10 Vpp. Idk but I'm not sure if 5V is enough to turn them on. I should try to put it in stick welding mode next that switches off the HF start which I suspect.I dont have gas connected at the time so I shouldn't be making arcs. Does anyone know if it's stupid to choose a resistor for the set amps and see how that goes? IIRC the machine will start even with a dead short.My issue continues to be the fact that I get hardly anything on the rectifier while the transformer should be running and the output is open.
>>3002846More suprises:Yes it was the HF start messing with the gate.Oddly in stick mode it uses both primaries on the transformer. This makes no sense unless it's a function promising easier stick start or something, because the second primary is only needed to provide AC on the output.I had to revise the schematic I realised the one I drew earlier made no sense at the output. Here is the new one. Negative output is on the transformer center tap. So the final stage is much like a push pull but in reverse.
>>3002851Check the smol caps near the pair of transformers in >>3002534
>>3002851This makes me think: I might have the primaries hooked up in the wrong fashion. This would be a PITA to change again. I have no definitive knowledge about the function of the gate drivers so they might not be synced or antiparallel in the way I suspect. So the fuck all I'm seeing on the rectifier might just be some residual cross conduction from one side turning on before the other turned off. But for the type of converter both switches need to be on. Begs the question how to measure that. AC coupling and the full voltage appears on the scopes input capacitance. Run it with the gates disconnected and hope the pulldown is enough to handle noise, disconnect gates and short to source, disconnect mains (PITA), disconnect mains relay on the board, add disc caps to probes...It would suck so bad if the primaries are crossed over.
>>3002855I think I buzzed everything out when reversing the gate drivers. I will do but I think it would have shown if they are shorted.
>>3002858I disconnected the relay and checked the DC link to chassic GND. The relay switches only L or N. No matter which way I turn the plug I am getting half of mains. After disconnecting it drops back to zero almost instantly, if the caps had charged it would be significantly slower. Why would that be? Shouldnt it read zero or close to zero if only N was connected and mains if L was connected?
>>3002860Gates are doing fine. It came to. me that I tested them all in DC TIG mode first, where it uses only one primary and the transistors that I expected to be a pair were being driven. They are connected by a primary. Bad news I guess. More issues.
>>3002859>shortedDid you test ESR?
>>3002865No I have no means to other than generator + scope.The driver seems to work well. More head scratching. This is not what I saw on the gates. The gates looked like this but capacitively coupled. Please not leaky gates.>PicrelWhat I got on the gate earlier. Settings were different but really looks like the same capacitively coupled.What I get on the driver.Capacitive divider to generate reference.
>>3002868picrelDouble checked. Then realised: Those are not IGBTs. I thought I had checked the datasheet. All 4 BJTs seem fine so far. BJT explains why the voltage after the base resistor is clamped to one diode.They are marked FGA60N60 but maybe they are BJTs in a fake package? With the driver disconnected they all have one diode drop between gate / base and source / emitter. Can't be that all 4 IGBTs failed in an equal manner, can it?
>>3002870Absolute shitshow.Testing across primaries.Getting about 300 Vpp 25 kHz across ome primary. Roughly where it should be figuring in the drop of the rectifier and the transistors themselves. So this means whatever is up with the gate voltage situation the transistors are at least somewhat okay. But the waveform is fucked up. Like saturation. Well it's got no load om the output. So under those conditions mhmkay. The other primary has hardly anything, could be capacitively coupled from the first. Especially since the waveform looks similar.
>>3002873I believe to have narrowed it down:Only transistors 1&4 or 2&3 can be driven at any one time. Unplug the other two - > square wave. Removal of the gate resistor is sufficient. Else the fucked up signal. This is without mains power (relay deactivated). For this T1 & T2 and T3 & T4 connect to one coil. T1 and T3 are LS and connect source to GND and ofc T2 and T4 are HS and connect drain to V+.It is not the load. Every gate looks like 1kR to the driver. Loading a single output with 220R and the driver remains happy.I know the transformer has no short on the primaries.It is almost as if this depends on the states of the transistors. I doubt that one transistor manages to pull the others gate somehow. I'd rather guess it has to do with a transistor pulling the other transistors source potential low and the driver not liking that somehow?
>>3002865In circuit all 10 uF caps read 10uF+
OP here. So, I moved the TV to show my setup where I have some better light and now it is not doing it. I put it back to its original spot and it is still not doing it. Weird. Shame about not being able to add connectors to it.
>>3002892If you plug the TV into an isolation transformer you could add composite & audio input without issue. Otherwise you have to use high speed optoisolators and 1:1 audio transformer(s).
>>3002897I'm not allowed to comment on those matters ITT so I'll just remark that.
>>3002902Picrel, not >>3002603
>>3002819>in audio designsSome amplifier topologies (especially diy ones) use the op-amp to drive a class-AB stage directly, so the slew rate matters just because you’re driving high voltage amplitudes into your speakers. Such a topology is also subject to clipping, most other audio circuits are probably designed to avoid clipping at maximum input volume, but I can see it being an issue for low voltage circuits (e.g. 5V single rail for a USB DAC).>you mean passes existing noise throughYeah, as I said it’s a component of your noise budget. Your power rails and input circuitry can only be so quiet. Usually just having linear regulators on your op-amp power rails is enough for audio-grade PSRR, CMRR might be handy if you’ve got an unshielded ungrounded system but I’ve never run into common mode audio noise myself.>they just convert physical phenomena, a digitizer that may be downstream would have finite resolution and so onDon’t see how that invalidates anything I’ve said. Even if a human eye cannot tell 16K video from 6K video, having a 16K camera allows you to digitally zoom around your image in post. Exact same reasoning behind using a 32-bit microphone. Just because a sound doesn’t fit within the comfortable range of human hearing doesn’t mean there isn’t reason to record it.As for the piezo element, driving outside of resonance can definitely produce a usable output, but you’ll be wasting a decent amount of power in your driving circuit, and have to use a pretty high voltage. Capacitive loads are a pain. Well if the Q factor of the mechanical resonance is low enough it won’t really matter how you drive it.>>3002823How is that 60Vp-p max into the drivers, when you’re outputting up to 60Vp-p before the 62.5:1 transformer?
>>3002892Some form of TV interference. Whip up a little wire antenna on the end of a length of coaxial or twisted pair line going to one of the antenna plugs and wave it around your house to see where the noise is coming from. Maybe you can kill the noise with ferrite beads on the TV or offending appliance.
>>3002935>How is that 60Vp-p max into the drivers, when you’re outputting up to 60Vp-p before the 62.5:1 transformer?It's an impedance matching transformer designed for maximum power transfer based on impedance ratio instead of stepping up/down with a turns ratio.
>>3002941That's not how impedance matching works. If it's not a 1:1 transformer, there's also a voltage change. If it is a 1:1 transformer, there's no impedance change in the first place.
>>3002946Why don't you lay out the entire theory then, Professor Reverend Dr. Magneto. I'll check in every hour to let you know how wrong you are. lmao
>>3002950Ok assume we have a sine wave coming out of a RF amplifier's 50 ohm output, with a power output of 2W. That's 10Vrms, 0.2Arms.Then we want to change that to 300 ohms, with a transformer or an LC matching network or whatever. 2W at 300 ohms is 24.5Vrms and 0.0816A. The voltage ratio is 2.45, the impedance ratio is 2.45^2 = 6.0.In either case I'm assuming that the transformer or matching network will have no resistive losses, in reality you'd aim to minimise any such losses as is reasonable. A lossy impedance matching network (a resistive divider) could also exchange impedance from 50 to 300, but transferred power would drop substantially. Both in the case of a piezo driver and a radio amplifier, such an approach would be undesirable, because as you said, we want to design such a system for "maximum power transfer".
>>3002952How does core size/material & permeability at variable audio frequency range up to 40kHz factor into power transfer?
>>3002954I haven’t looked into it too much. Lower frequencies seem to need higher inductances to carry the same power, so I’d assume there’s a rule of thumb for signal impedance with respect to winding reactance. You’d select this for the lowest audio frequency you care to accurately recreate. Common isolation line-level audio transformers (e.g. in microphones and ground loop isolators) don’t need to couple much power at all, and thats the only time I’ve dealt with audio in a transformer.So low frequencies at high powers seem to require high inductances, but they also most stretch your core towards saturation. I’ve tested a few different core materials for power electronics, and there’s definitely a trade-off between high field strength before saturating and high inductance. Air-gapped ferrite cores (like flyback transformers) have lower inductance for the same number of windings than an equivalently sized solid ferrite core, but more than make up for that with their maximum amp-turns. I found that out after doing some testing with a clip-on ferrite suppression sleeve, increasing the number of paper shims between the open end. 16 turns around the core with no shims had an inductance of 640uH and a maximum of 18amp-turns, while 6 paper shims dropped the inductance by 4x to 160uH while the amp-turns increased by almost 6x to 105. Because energy stored is a function of the amps squared, it could then store almost 8.8 times as much energy before saturating.There’s also a lot of different types of ferrites. The general purpose toroids I’ve found are high-loss at 100MHz and easy to saturate. But balun cores seem to be lower loss and higher inductances in general. And thread-on ferrite sleeves were high inductance but always high-loss, with a measurement range from 15kHz to 600kHz.Powdered iron cores are somewhat high loss, but can take a lot of amp turns.
>>3002936Yeah, this place is a mess. Built in the 1950s. One room in my house has all sorts of infrared interference so you can't use IR remotes in it*. Only the kitchen and bathroom have grounded outlets. The fucking main breaker in is a car port and doesn't have a cover. And it hums sometimes. Most of the wiring is picture related and the insulation turns to dust if you move it. The entry point for the power lines is on the literal other side of the house from it. Which is also where the fucking grounding rod is. They blew in about 4 feet of cellulose insulation in the attic at some point so I can't even tell if the wires are run up there or not. Oh, and the breaker box has not one but two breakers that I have no idea what they go to. I flipped them off and not a single outlet, light or appliance in the place stopped working. I suspect one is for an attic fan we had removed, why it would have its own circuit when it was a 3 amp motor is beyond me, but I have no idea about the other.*I even unplugged everything in the place, removed all the LED light bulbs, and closed the curtains and it is still blasted with IR.>>3002897Well, an isolation transformer is out. Pricey. Plus the 'cheap' ones seem to not actually isolate anything? Fucking China.The optoisolators looks interesting. All of this is over my head but I can solder and follow instructions without setting anything on fire too much. Do you know someplace I clean learn how to make a PCB that could handle that? Composite I guess. I could tie that into the PCB somewhere upstream of the RF modular right? >>3002530 said the jungle chip could handle S-video but I don't have much that supports it. Plus I actually have a Commodore 1702 which supports it natively.
>>3002965>Composite I guess.I was going over the schematics and, if I am reading this properly (please remember, I am an idiot), it goes from the RF chip (IC201) to the jungle chip (IC301*) on the chroma and luma pins. Does that mean I could tie into the circuit somewhere between pin 19 on the IC201 and the Video Amp Q202 with a composite video signal and the jungle chip would handle the rest? With an optoisolator so I don't kill myself.For audio, could I do the same by putting the signal in between pin 21 of the IC201 and pin 8,9 on IC202? Again, with an optoisolator,*UPC1352C https://datasheet4u.com/download/511124/UPC1352C.html
>>3002970Doesn't look like there's distinct chroma and luma at all, just a single trace carrying composite video out of IC201's pin 19.I'd consider desoldering Q202 and use its output pin to wire up your video output. And probably resolder Q202 onto your custom board. Assuming Q202 is easy to work with.I have no idea what optocouplers are available for isolating a video signal, I'd be tempted to just try some sort of a simple isolation transformer, but that's just a naive guess. No clue how DC bias or linearity compares in either case.For audio, there's already an isolation transformer T631 between the audio signal and the speaker (and the earphone jack), just use that. But it appears to be mono, so you may want to upgrade that anyhow, or just not use its internal audio capability in the first place.
>>3002873So I spent the rest of the time reflecting on why the gate driver can't switch on two switches on the same coil. To no avail.>PicrelIf I get to assume a mix of AC and DC conditions and ideal transistors I arrive at this. L and C could be shorts and switches closed. I believe it would be the same if either L or C wasn't shorted.The drivers are isolated and do not care.I have also found out why my diode test reads 0.5V from gate to source on every transistor. It uses 500 uA and drops 0.5V on the 1kR pulldown, tested with anothwr 1kR. Tested the zener diodes individually and they're good.With IGBTs isolating the gate signal I can only see three possibilities:- I's got to do with the source connections... but drivers are isolated.- It causes shorts that nuke the whole supply and trip up the gate driver... but everything else ses to keep running and fuses stay put. - The controller simply ramps up to 0.5 duty cycle when the mechanism is defated and very little if it's haply with what it's getting. It wouldn't explain why the same is observed without the relay for mains. Also yesterday the scope showed the driver totally crap out intermittendly. Could be the controllers work but not likely. I have a few more ideas what to do:Bridge drain source on one device and see if it does the same - aka if it's the device state or the driver connection.Hook one gate up to battery power and see if it behaves the same, same idea basically but also to check how much current it takes to keep the gate high.Bridge two transistors and buzz out shorts.Find a point to test upstream and see what the controller is doing and whether it's changing it's behaviour.
>>3002982sorry for all the obvious mania,it is working and has been since the fix on the one dead board. I am getting 150V DC on the DC link when idling. It must have been a shoddy solder joint when I added hookup wire for probing.This also implies the ugly gate signal >>3002870 is ugly but working. The appearance is probably due to the superposition of a very brief gate drive pulse (doesn't even reach full voltage), presumably the pulse from the other side coupling in and lastly some of the tansformer waveform coupling in.It's just not all bice and super clean but I have a good bit respect for chang working under conditions where his boss doesn't let him use any ICs but 'only the logic gates, OPs and passives we have in the bins'. The whole thing appears to be a very good exercise in economics and punishing lower caste guys like those in manufacturing and assembly. It's like someone purposefully went against DFAsm and DFManf.I will investigate a few kore thingsmI want ro completely reverse the gate drivers and a few more things, there is alot of cool ideas and circuits in there that could have only come from looking at others designs alot or books.
>>3002989REEEEE
>>3002990It's definately working. Counting it as a win! I finally have the confidence in it working that I needed to put it back together completely. And arc flash already!Because I'm lazy I rigged 2S5P 3.3R 10W so that gives 6.6/5 or 1.32R. The lowest programmable Amps are 5 according to manual, 7 according to what the machine reads out and god knows how much in reality. Didn't want to risk my 10A unfused meter. So that's 65W if 7A is right and I'm only doing short cycles.>TestIn stick mode at the output under no load It read 75V. Across the resistors it dropped 8.5-9V this gives the 7A as the display reads out. Good.Massive arcs when disconnecting. I think the controller does something to maintain arcs even for people too dumb to stick weld. Still seeing the arc.
>>3003002I have fucked up the polarity.>take it to the shop>hook everything up>try TIG>tungsten almost burns up and ruins a glas lens>feels like wrong polarity>check in the pictures I took>it's clear. Connections on the output driver board are reversed>this should have become clear when my meter explicitly said it's negative polarityTFW
>>3003023THERE WE GO!finallyEverything works again. IDK why I need 4 TIGs but meh.
>>3002970Build a selector switch with a THS7314D, ADC, and fiber transmitter inside that connects to the TV over single-mode fiber optic cable. Then put a DAC and fiber receiver in the TV and inject that into the jungle chip. lmao
>>3003042>THS7314DTHS7313 adds i2c control and 2 selectable inputs.
>>3003030Congrats. I’d like a welder myself, what’s the chance I can just buy a broken one and fix it? What kind of welders are easy to fix?
>>3003074>What kind of welders are easy to fix?Arc welders.
>>3003074The way I see it chances are very high. The impression this one left on me was: Skookum as frigg.Electrically it's a very rovust design and not much can go wrong with it. This is backed up by me running it under all sorts of invalid states (defective output driver, random gate drivers disconnected, output driver crossed over etc.). It is also corroborated by the fact that the only thing that was wrong with it was one electrolytic capacitor. Not a design or manufacturing error on the welder companies side, if anything a procurement issue but in any case an issue that befalls almost all older electronics. The expensive bits are those that switch the power, contain lots of copper or ferrite and those appear indestructible. Worst you are replacing diodes or transistors at 5 bucks a pop.This exact model was a white label product. I suspect any chinese welder from the era that has the same capability is the same design.Other welders I've been into seemed equally robust and easy to maintain or repair. Just keep in mind the smaller the thing gets for the same power the more voodo and MCU you can expect to find.I'd shoot my shot.
>>3003080>it was one electrolytic capacitor.Which one?
>>3003081>Which onesee thread.>probably C69 or so, hope that helps>picrelI wanted to explode it proper and it wouldn't even gibe me the satisfaction. Just a little pop.
>>3003079Isn’t every electric welding machine an arc welder, bar spot-welders? SMAW, GMAW, etc.I’d prefer being able to do TIG and MIG, and AC for aluminium, and don’t really have room to stow 3 different welders. The question was more about what topology (e.g. inverter, number/type of transistors), brand, and year I should be on the lookout for.>>3003080What year is your welder from, early 2000s? I do find that level of discrete logic very appealing from the perspective of reverse engineering and troubleshooting.
>>3003096I think I said it last thread but date code is also all over the pictures ITT it's 2011.I do not thibk you'll find a machine that TIGs and MIGs. Back in the day some machines were modular, perhaps that's possible. Like you had the main transformer / inverter and a seperate unit that does the feeding.
I've got a few of these I'd like to have around the house but I don't want to buy the power supply at $50 each. I'm a beginner in electronics. I have a bunch of those 12v power supplies that I think could work to power the LED panels.Is it as simple as connecting the wires and taping it off or is there another safer method?I have one 12v power supply that reads Output:24v = 0.75a. Does that mean it should only be used to power 2 of the LED panels?Here's the product I'm trying to save money on, might provide more information: https://www.bunnings.com.au/kaboodle-12v-15w-led-driver-and-distributor_p0176166
>>3003137Ok makes sense. I'm guessing there are existing products to add MIG feed that tap off the same pedal signal, if not it would be pretty feasible to DIY that sort of thing. I could feasibly handle the gas turning on and off externally to the welder also, allowing me to use a machine designed for stick or other fluxed welding, but getting a machine designed with TIG in mind seems like the way to go.>>3003138>I have one 12v power supply that reads Output:24v = 0.75aThat's not a 12V power supply, it's a 24V power supply, might want to check your brain. If the LED panels are sufficiently well matched or stable in series (they probably are), yes you could run two 12V panels in series off a 24V supply. But in this case, 0.75A @ 12V = 9W, and those LED panels want 9.2W. It might not be a problem, chances are those PSUs are just going to run hot, but that's not good for their longevity. It could possibly go into some sort of protection mode, turning on and off as the current or temperature gets too high. I'd want to use a dedicated LED power supply that goes into constant-current regulation if I was running it that close to its rated power output.Each LED panel theoretically draws 0.76666... amps, so you want to add up panels such that they're using most of each power supply's rating. Say if you had a 12V 2.5A supply, you could run three panels in parallel at 2.3A total, that's a safe margin of error. If you bought their 30W driver you'd be able to run three LED panels off it, instead of their 15W driver that you listed that would only allow for one.
>>3003138>Here's the product I'm trying to save money onyou can def get adequate supplies much cheaper current prices i'm seeing at thrift stores is around 2 canadian pesos
>>3003142>handling gas externallyFor TIG that's a common thing, valve on the torch. Works well but can make the torch bulky.For MIG? Why? For MIG I want the gas to come on when I press the button and bobs your uncle.>PedalAgain for MIG? No thanks, the things I work on and places I work in with a MIG are definately no pedal places and I dont see why I'd want a pedal for MIG. Hit the button and lay down weld.Besides that:Any recent TIG machine unless painfully cheap will have a gas valve, so provided you do something to the logic, or MIG in TIG mode and lockout the HF start or just hook the gas valve up directly to the button input, you already have gas control so I'd imagine you'd want to feed it through the feeder unit as you want one place where you hook your cable up and not sort of try to tee off to a bottle or something.>flux corenever done that probably ass just stick itWhat I really like about the box, now that I have seen it and understand the grand picture of operation: The thing is a 200A programmable current source. Probably wont go very high voltage at 200A but apparently goes close to 70 at low settings. There's a whole lot of things that thing can be useful for.I almost regret it wasn't shot and I would have had a reason to get the goodies desu. >>3003138Since it says "12V" and nothing else I wonder if it is somehow regulated. At 9W I could even see how they just put series resistors in that burn a little. If it had no current limiting I would expect it to explicitly state the current. But the math says you need 770 mA.What I would do is see if you can get something that is limited, or put something inline to limit the current to double that and run it very briefly to judge if it's obscenely bright, implying it has no current limiting. Even better if you make it adjustable.If it isn't very bright at 1A and above it's safe to assume it's somehow limiting current and you can hook any regulated 12V supply to it. No need to shell out 50 bucks.
>>3003202cont.If on the other hand you discover it is not current limited, unlike the label implies, then you have many options, DIY or buy, almost all of which come wa, below 50 bucks and the cost or effort really just boils down to efficiency and neatness. If ydgaf you can pull a 12V transformer and rectifier out of something and make a transistor current regulator, 2 resistors, a zener and a transistor get you there, maybe less but it's almost the same as just putting resistors in series.
>>3003202>For MIG I want the gas to come on when I press the button and bobs your uncleWell yeah, if I’m using a welder that’s just a power supply it won’t have a gas outlet or a wire feed, so both would need to be controlled externally. Whether by pedal or button for the TIG, or trigger for the MIG, I’d want it to be automatic. A valve on the handle for TIG seems like you’d waste more gas compared to automatic gas feed.A quick look locally and there’s mainly just some ancient stick machines, and some functional $150+ MIG machines. I should look for industrial auctions.
can i put a 12v dc motor speed controller inside a small airtight sealed box? it powers a 20w pump its for outside and won't run more than 12 hours max at a timewondering about the heat
>>3003218That should work. And you don't need to go deeper than trying it out. A larger box will have more surface area which helps.In the end it depends on controller efficiency (or losses), which I assume to be high and the ability of your box to get rid of the heat. 12 hours or indefinately should not make a difference and you should design for continuous operation anyways. For thermal models you can use common electronic concepts, it's all RC networks and a source, everything has a resistance (insulation) or conductivity for heat and a thermal capacity. The later can be ignored for a steady state case. Isothermal points (ambient) can be thought of as a potential source.Plastics are generally on the order of 0.1 - 0.5 W/m•K.Idk lets say your box is 2" and all around so you get 6x0.025^2 = 0.00375m^2 and for simplicity lets just ignore the air inside and the thermal junction between controller and air and air and box. Box is 1mm thick. That then means we get 0.1 - 0.5 W * 1000 / m^2 * K and taking into account the box geometry and again ignoring convection and radiation at the outside the box gets rid of 500 x 0.00375 W / K.Electronics are usually happy to at least 60 degrees C or so, ambient 20 C gives us 40 C of headroom at which point the box gets rid of 40 * 500 * 0.00375 W which is 75W!That's alot, alot more than I would have guessed. Someone double check please. Maybe I moved a decimal.But you get the idea.>Coaxial vs twisted pairWhen doing up the welder I was sort of delightes to see all those twisted pair wires. Amongst other things it just screams 'getting things done'. They just do anything they can get away with if it works and saves cost. This makes me wonder: How much worse is twisted pair (for asymmetric signals) generally when compared to coaxial? And I'm not talking differential. They literally solder wires to gate and source on one board, give them a twist and solder it to the GDT on another board. Is that even really asym?
>>3003226I found my mistake. I have dropped the range for plastics thermal conductivity half way, so you get a range of 15 - 75W which still seems high IMO but there's still the convection and conduction inside the box and outside the box which will lower the result. Still seems safe to me. Your speed controller must have terrible inefficiency to fuck this up. If you ca shape the box (say 3D printing) give it more surface area like hollow fins.
>>3003218If heat is a problem, use an aluminium box and thermally bond the speed controller’s transistors to the inside of the box. Electrical isolation is a good idea. Add a thermal fuse or thermal breaker if you’re worried.I doubt you’ll need fins or forced airflow for a speed controller (probably less than 25W to dissipate), if you need more dissipation you can thermally bond a finned heat-sink onto the outside of that waterproof aluminium box. A compromise is to bond the heat-sink directly to the speed controller, then cut a heat-sink-sized hole in a plastic enclosure and fill the gaps with epoxy or maybe a polyurethane glue. Ideally there’s a flange of the heat-sink sitting against the plastic, such that it isn’t just a glued butt-joint. Easier to get a good fit around that heat-sink with a 3D printed case.Cheapest option might be to use thermally bonded sheet aluminium as the lid to a plastic (printed) box, with a gasket squished in between.
>>3003226>>3003246thanks bros very cool info gives me a few paths to make it work without worries
>>3003042>>3003044Thanks for the info but I don't know enough about this stuff to build my own circuit. I found this one online that is video only. Would this work?
>>3003288That’s basically the recommended schematic from the datasheet of that opto. As for the circuit layout, it’s 17MHz bandwidth so you don’t have to worry about transmission line effects, I’d just ensure you have a solid ground plane and return paths for all signals. Personally I’d add a ground plane to the other side of that YouTube layout too, with stitching vias around crossing traces at minimum. I also prefer the TO92-wide footprint and horizontal resistors.Maybe there’s more details for recommended PCB layout in an appnote, or in an existing product.
>>3003288>>3003296
>>3003296I got it from here:https://antiqueradios.com/forums/viewtopic.php?t=430210There are a couple of PDFs and gerber files. I was just gonna make something using a prototyping board.
>>3003341I wouldn’t use prototyping board to make a high frequency analog video circuit. Let alone a circuit needing high voltage isolation. I’d sooner use manhattan style.Though gluing a piece of strip-board (especially the breadboard patterned stuff) atop a piece of copper-clad FR4 as a ground plane is pretty convenient. You just have to solder components flat atop the stripboard instead of through the holes. In this case, to break up the two ground planes, you’d want to cut or etch a gullet between the two sides of the base copper-clad, and have seperate stripboard pieces on either side.
>>3003368There’s the lazy manhattan method I used.
>>3003372What would happen if you used a piece of copper foil tape on the bottom of the stripboard instead of copper clad?
>>3003376So long as you can solder all your ground wires to it and it isn’t making contact with the pads in the protoboard (don’t use the two-sided protoboard) it should be fine. I’d want to use really wide copper tape, to give good shielding to all the stuff above it.
>>3003368>Manhattan styleWow, I'd never even heard of doing it this way. Shows how much of an amateur I am. I've soldered a bunch and am quite decent at it. Replacing all the RAM and a few of the larger chips with sockets on a C64 really dialed that skill in. It has all been monkey see, monkey do type stuff though. Putting together kits, replacing components on an existing board, copying existing designs that kind of stuff. How about a little prototype board for the IC, some standoffs (I have some boards with larger holes in the corners for these), and then the FR4 under that? Would I need some layer of shielding between them?
>>3003391Oh, scratch that. You can put chips on these like a dead bug prototype. I can work with that.
>>3003391Protoboards have trash grounding and are hard to desolder/rework if you make a mistake. Deadbug, Manhattan, and point-to-point are definitely the way to go
>>3003395>Protoboards have trash grounding and are hard to desolder/rework if you make a mistake.I've never had a problem with desoldering them. I've even reused them before. I didn't know about the ground issues they have though. Having also had to fix grounding problems on a Vectrex, which are notorious for having a constant humming sound because of a ground loop and poorly insulated wires, I can see the concern.
>>3003391The problem with that route is you’d have a much larger gap between the ground plane and your signal and power traces, than between those traces. Capacitive coupling and crosstalk would be hard to mitigate. At least with a single-sided protoboard flush against the ground plane those distances would be closer. Honestly single sided protoboard is just better than the double-sided stuff. Easier to solder and desolder, with a wider variety of layouts. But it is easier to delaminate pads since it’s almost all FR2.>>3003392Yeah that’s probably the most robust method. I prefer sticking little pads of copper-clad atop the ground plane as opposed to cutting isolation slots around pads, but either works. But I would carve or etch an isolation slot at least 5mm wide. Less would be acceptable if there were lacquer or solder-mask atop it.
I'm looking for a PCI-e 1x connector, but all the cheap ones I see are THT. Isn't that really bad for high speed? Why would they even make THT versions of high speed connectors if that was a problem?
>>3003426as with all things RF, It Depends. you can design the connector and footprint to have the desired impedance at the operating frequency/ies
I was told that old coax cable is a cheap solution when you need shielded wires. Cut the connectors off, solder the shield to ground, and use the core as your wire. I can get pretty long lengths of the stuff for a buck at the local thrift stores.
>>3003559>shielded wire is good if you need shielded wiremakes u think
>>3003559>old coax cable great quality but there are drawbacks which make it nasty to work with- quite large, so ugly and hard to hide- stiff, difficult to bend around sharp corners- mono only; need 2 runs of wire for stereo, more for video- shield needs big-watt iron- stiff center wire is sharp when cut, will poke holes in your fingers
>>3003563
Here I am stressing about what to do with my layout that requires the + and - pins of my ethernet traces to the swapped in order to keep everything on one layer, then I learn that in ethernet polarity literally doesn't matter and I can just wire + to - and vice versa and it'll be fine
FUCK SOLDER BRIDGES (OR SOLDER NIGGERS)I HATE THEM WHEN THEY ARE UNDETECTABLE UNDER CONTINUITY MODEI wasted 2 hours debugging I2C problem on my level shifter
How the fuck do I route this USB-C connector? The data pin pairs are blocked by each other so they cannot neatly connect. Seems like I have to go all around the back of the device to connect them, doesn't that completely fuck the impedance and length matching requirements?
>>3003644Something like this maybe? This is fucking stupid
>>3003644Things like (fully functional) USB-C connectors are meant more for ≥ 8-layer boards.
>>3003661The number of layers wouldn't even matter, they are THT holes, they block all the way through
>>3003559Mr carlson was wrong about one thing… something like RG6 with steel center conductors (CCS) is not good at low frequencies due to attenuation and it’s a bitch to work with.Whether you’re using RG6 or the thinner RG59, try and get copper center conductors.The reason they can get away with CCS on tv cable and satellite cable is due to the skin effect at very high frequencies—the signal stays on the outside of the cable where the thin copper layer is.Generally, with modern drivers, we can get away with over 3 GHz on this cable tv coax now so there’s ways to use it for high-speed digital networking using the wire that was built into your home back in the 80s.There’s other, better coax you can get, like sirius/XM radio antenna wire that has excellent characteristics and you can find good audio coax with broken microphones—the low voltage signalling needed good shielding.
A Weller 3439-00-460-7198 is going up for auction in my area. I researched it online but couldn't find a ton. I think it is a 40 watt Weller EC1201A soldering pencil, which takes ET tips. Spare parts do appear to still be available. Assuming I can get it for super cheap (<$20) would this still be a decent pack away iron as a spare/travel? My current iron is an 10+ year old Hakko FX-888D and I think it works great. Is this Weller gonna be a serious downgrade?One thing I like about it is it has a ton of tips and desoldering attachments.>>3003665Who is Mr. Carlson?
>>3003644Man, just use an SMD socket instead. Pretty sure I’ve seen vertical ones, with the pads spread out in both directions.>>3003668Fat handle, ergonomics might be kinda strange. But I see no venting on the shank of the tip, so I assume it’s temperature regulated? A quick search suggests it’s curie-point controlled, so fixed temperature. Should be damn reliable, but those tips may not be designed for lead-free use. Naturally it will be less capable than a cartridge-tip iron or an iron wth greater power. 40W seems kinda low for that big DIP reflow tip.
>>3003683I was just going based on what I was able to find online, which is just about fuck all. Weller's naming conventions, constant model changes, and other bullshit has just about done my head in. The box says WTCPK and 24 volt, 48 watts (my bad, not 40). Outside of a single line in a very old Weller catalog and a bunch of old military TMs I can't find much else about it. The EC1201A comes from a video on YouTube were a guy replaced some parts on one and had links on where to get the parts. The tips in the box say PT but what is the difference with ET? Fuck if I know. The box says the tips are for 600 or 700 °F so I assume it can get at least into that area.
Anybody have this screen and was able to free the CS pin from the driver? The header does not come with a chip select meaning you cannot have this screen and other SPI items on the same line the way it stands. Pic-related is the pinout diagram I made. The 3v3? Label turned out not to be 3v3, U2 is the backlight power module. Screen (from Amazon):DollaTek 2.4-inch TFT SPI LCD module, 240×320, using the ILI9341.My fallback plan is to permanently use a Blue Pill to run it then send the Blue Pill whatever I want to show on the screen, via SPI for speed.
>>3003779Just put a transistor or logic gate on the CLK pin. Maybe MISO too, if you need to connect that in the first place.You could also use other pins on your MCU for another SPI peripheral, be that alternative hardware SPI pins, or software bit-banged SPI. If you planned on using another SPI line to talk between this MCU and something else, they you’d already need two SPI channels. Or are you otherwise pressed for GPIOs?
>>3003668> mr carlsonWe’re talking about https://www.youtube.com/watch?v=s5kU5SeaSQs
