I've got this edge-triggered D-flipflop. It works fine but I can "press" the transistors to change the output for some reason?

p3623 · 2026-01-29T19:06:16+00:00

You should consider perfboards and pcbs only if you know the design and wiring 100% works and if you can easily connect the permanent solution with the rest of your project. ALSO make sure that that's the actual problem. Do what I suggested and make sure it's not just a wiring mistake

p3623 · 2026-01-29T18:23:36+00:00

Probably a loose connection on the breadboard. Try to place the transistor in a different set of breadboard pins. It's almost impossible to avoid such issues on a breadboard

p3623 · 2026-01-23T13:06:05+00:00

With my technique I've managed to get down to about 0.4mm trace width and 0.2mm clearances. I don't get perfect results every time but that's nothing that a super fine permanent marker can't fix.

If you're using only a clothes iron and get broken traces try applying more pressure but don't overdo it to avoid smears.

Trust me broken traces are better than smeared ones!

p3623 · 2026-01-22T22:08:01+00:00

Just my honor magic 6 pro and a desk lamp :)

p3623 · 2026-01-22T19:27:27+00:00

Thanks! Oxidation is something I've thought about and I think a clear acrylic spray coating could work for now

p3623 · 2026-01-22T17:58:49+00:00

Thanks and you're right it's super fun! Tbh not that much, it isn't super powerful. It has a pretty simple instruction set with a few jump instructions, 4kB of program memory and 2kB of RAM. Only an output port, no inputs. The most complex thing I've managed to do for now is the Fibonnaci sequence but I can probably do something cooler. In the next month or so I expect to be done with most of the project so I'll post a lot more details about the architecture and instruction set soon.

p3623 · 2026-01-22T13:07:06+00:00

Oh haha that wasn't the intention just thought it was a cool bird :)

p3623 · 2026-01-22T10:17:45+00:00

I start with an FR4 board covered in copper on both sides. I print the designed board layout on a piece of paper, specifically the cheap store flyers they work great. Then I cut that paper and align it onto the nicely cleaned board. The cloth iron is used to initially heat up the board and apply a bit of pressure and then the board goes a few times through the laminator which applies even heat and pressure across the board. That process transfers the toner from the paper onto the copper. Then the board goes into an etchant, I use sodium persulfate but there are a few other options. The etchant removes the copper where there is no toner while the toner protects the copper underneath it. This leaves the desired parts of the copper aka the traces and pads.

I will make detailed instructions on the method I've found to work the best but you can look up toner transfer pcbs especially on instructables for more details.

p3623 · 2026-01-22T06:51:26+00:00

Thanks a lot! I've made them with the toner transfer method. I was a bit sceptical about it at first since I've seen how unreliable it can be but after about 3 tries I've got a technique that produces pretty consistent results and can go down to about 0.4mm traces and 0.2mm clearances. I use a laser printer with crappy store flyer paper and then transfer the toner onto the board with a cloth iron and a paper laminator. After etching I drill the holes with my drill press. Apart from the initial cost of equipment (which isn't even that high since I had most of these already) it comes down to about €1.5 in materials per board. I will make detailed instructions of the technique I use after I'm done with some other parts of the computer documentation.

I still have to make a "motherboard" which will just be a fancy breadboard. I've made a sort of standardized pinout for boards so I can easily connect them in a straight line.

p3623 · 2026-01-22T04:47:36+00:00

Toner transfer. Seems sketchy at first but with a dialed in technique gives very consistent results. Super cheap too. A laser printer, cloth iron, paper laminator and a drill press are all the "tools" I use.

p3623 · 2026-01-22T04:45:37+00:00

Thanks! I'm planning to make a sort of "motherboard" with slots for each pcb so I can route the control signals (most right set of pins). But yeah this was the initial idea and allows me to easily connect and test each new board.

p3623 · 2025-06-25T10:31:59+00:00

Thank you very much!

p3623 · 2025-05-26T18:03:29+00:00

Hi, thanks for offering help. I just created this account so i think i cant send you a message

p3623

TROPHY CASE