Update:
I could debug the box and now everything is now working as intended. I have to say I should have build this thing sooner. Before this I only knew the 2b and now since I can compare the two I have to say the 2b is Pain with a little bit of pleassure while the DIY box is pure bliss.
Now to the build itself. I changed the case. I completely underestimated the dimensions and wiring. The main problem / space eaters were the ressistors. So I went back to thingiverse and looked for another case design to use:
https://www.thingiverse.com/thing:3850905
This case is meant for an ITX computer so it offers plenty of space but since my printers print bed isnt that big i had to reduce the size to 90%
Ive decided to split the box into two layers by designing a mounting bracket:
- Spoiler: show
- Screenshot_657.png (48.33 KiB) Viewed 4350 times
The bracket will pushfit into the existing wholes of the case:
- Spoiler: show
- Screenshot_658.png (43.01 KiB) Viewed 4350 times
The first layer of the case will be for the two transformers and the ressistors:
- Spoiler: show
- Screenshot_656.png (173.02 KiB) Viewed 4350 times
Sorry but I forgot to take a picture of the actual thing. to do that now I would have to redo the wiring afterwards which I dont want to do since everything is working as intended. Also its quite boring just some ressistors mounted to the box with wires attached to them.
While the upper layer is for the amp and the subcircuits to the transformer:
- Spoiler: show
Its still a bit messy and seeing that again now is really itching me to fix it immediately. During debug i replaced a connection circuit board with screw connecters that also has to be fixed.
Heres the box closed:
- Spoiler: show
- [img]blob:https://imgur.com/c031508c-811e-49a4-b745-baf46aa73377[/img]
Having this box now in a working state and everything left is cleanup, let me try to summarize my learnings:
- Lolols design is really easy to recreate
- The pots suggested by lolol had poor quality, no idea if i had just bad luck but 3 of the 4 10k pots were broken. Im sure im responsible for the failure of at least one pot due to taking to long with the hot soldering iron. But in general i would not recommend that kit. In the end I purchased these pots with a scale and im very happy with them:
https://www.amazon.de/dp/B07JYWRD27?psc ... ct_details
- Never do the first test on yourself. I made the first test with two pads on my leg and got shocked with what i guess was full power for a second. Use a multimeter and check AC voltage on the channels.
- Calibrate your amp output volume. Try to set the max output to something like 70 volts. Makes the box easier to control and you can better utilize your pots.
Im already thinking about building another box with some improvements and ideas. Here is some stuff I will tryout in a future build. Maybe someone who has done stuff like this can give me some input:
- Add leds to symbolize something is active (power, fan, channel, triphase)
- Add an optional fan for cooling if needed
- Add a third optional pot that controls both channels at once
- Find a way to have a digital pot that can put out its max value percantage based like a 2b or use a slider pot for better readability.
- Download (3).jpg (4.06 KiB) Viewed 4350 times
Is there a reason beyond space why noone has ever used a slider pot?
- Having switchable caps for the highpass filter (ty JakofClubs for the idea)
- Put plugs on all cables to make maintance easier.
- Add a killswitch on a cable that you can hold onto while stimming so that you dont have to try to get to the pots or the main switch on the box if a signal is too unpleasant. Im not sure how usefull this actual would be but i somewhat like the idea.
- Try to incorporate a chargable battery.
