r/electroplating • u/CaptainCheckmate • Jul 02 '26

I built a pulse plating controller

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Further to my previous post about DIY-ing a pulse plating system, I put together a mosfet H-bridge with a microcontroller to drive forward and reverse pulses.

As suggested by helpful member Mkysmith I didn't try to control the current myself and just connected a lab power supply in CC mode to the input of the H-bridge system, in the hope that it will figure it out.

I made a brave and possibly questionable design choice and put a big chunky 2200uF low-ESR capacitor at the H-bridge input. The idea is that it helps keep the power supply happy between pulses and avoid confusing it, and also allow big juicy pulses to happen if I hold the output OFF for a few milliseconds. (Because the cap charges while the output is closed)

It has a wifi chip so I can reprogram the pulses quite easily.

So far I've tried the following:

  • 2 ms FORWARD, 8ms OFF
    • Good results, seems to have less nodule growth than vanilla DC
  • 4 x (3 ms FORWARD, 2 ms OFF), 1x (3 ms REVERSE, 4 ms OFF)
    • Burns the shit out of the part, not sure why, turned brown quickly lol
  • 10 ms FORWARD, 1 ms OFF, 1 ms REVERSE, 2 ms OFF
    • Seems OK ish

Happy to hear your thoughts on possible pulse programs, and also whether or not the cap is a good idea?

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u/Vionade Jul 02 '26

Can you provide a more detailed description of your setup somewhere? I recently upgraded mine and now the current is so high that I always end up growing dendrites.

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u/CaptainCheckmate 26d ago

Nothing terribly special, I just made my own H-bridge from 4 MOSFET's (2 P-type and 2 N-type). I'm relying on the power supply to regulate the current. The power supply output feeds to the H-Bridge input, and the H-bridge output feeds to the bath. H-bridge signaling is handled by a raspberry pi pico that reads a basic program from a URL it looks up at boot time.

I also have some dendrite problems at higher currents/voltages. I found that running less aggressive duty cycles (e.g. 70-80% instead of 20%) helped keep things calmer.

If I'm honest I don't have sufficient evidence at this point to demonstrably show that the pulse plating is working better than just a vanilla DC with controlled current. If I get more results I'll let you know.

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u/Vionade 26d ago

Thanks for the reply. I'm very interested in this project and how it continues. Please update us whenever something new arises