Converting a dead smart trainer into a dumb trainer?

Math aside, do you know how and were he would actually connect this PS to the trainer? Presumably you are talking about bypassing the PCB and going directly to the EM’s in one way or another?

Yes, bypass PCB and feed power to EM’s directly, there one connector with two wires feeding EM’s. Polarity don’t matter on this case.

FCC reports internal pictures can be found here: https://fccid.io/PADWF123/Internal-Photos/Internal-EUT-Photo-3850566

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If I was to bypass the board and use the electromagnet, I would want a remote control dial to adjust the resistance.

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There is plenty of DC-DC converters on Aliexpress under $1, which could do the job. Like this:[https://ae01.alicdn.com/kf/HTB1bi6pUQvoK1RjSZFNq6AxMVXa5.jpg]

But before ordering one it would smart to verify what is actually needed / feasible. I would start by supplying 5V to EM’s and by riding verify load level achieved .

I’m not an electrical engineer. I can barely crimp connectors and solder. Explain like I am five.

To begin with, Is you trainer Wahoo Core?

Do internals look same as in FCC report pictures as on link I posted earlier?

Yes. Probably?

I mean I need to know exactly what components I would need to be able to adjust the output from minimal levels (resistance floor) to maximal resistance (1800 w).

If your original power supply is OK then all you need is adjustable DC-DC converter to replace your current PCB. But if you aim to full 1800W maximal resistance, there is danger of overheating EM’s.

If I were you I would just bypass PCB by connecting together wires from psu connector to EM connector and leave backdoor open to restore unit back to smart trainer. Just in case if suitable PCB-repairer/new PCB could be found.
Then I would use some PSU (or original PSU) and connect DC-DC conv between PSU and Trainer power supply connector.
Externally connections:
Mains power → PSU → DC-DC conv → Trainer power input.
Internally connections:
PCB power input connector → Bypass wires → PCB coil connector → EM’s.

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…is there some reason I can’t just hook the electromagnet straight to a light bulb or something?
I mean, a brake is basically a motor, is basically a generator… Hehe.

It is not a generator, it is eddy current brake.

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Ineos (apparently) somehow used Kickrs to power Christmas lights in a video several years ago.

Bike racing team with skillful mechanics, there should be no problem to change flywheel with permanent magnets equipped one. At least to level for powering decorative fun lights.

Hello!

@BT-7274

Did you ever get this sorted? Really cool project and would love to know if you found:

  1. Success!
  2. You powered any sort of lighting device
  3. Started an electrical fire

Thanks!

Hello! It’s been a while since your question but I just created an account to register the workaround I have made, perhaps this will help others in future.

I have a Chinese clone of wahoo’s kickr, the thinkrider x7 pro. It’s such a clone, hence same ESD issues with the mainboard. Thinkrider does not have a mainboard for sale, they are out of stock, so pretty much the same situation as Kickrs.

Following @Turnier advice on bypassing the PCB and being somewhat able to adjust it on the go as @BT-7274 suggested I came to the following solution:

I bought a DC-DC Buck Boost converter, this allows me to adjust voltage and current, the one I bought looks like the one below, there are lots of other options, they are all the same basically, just be sure to get one with the correct current (A), in my case it was 5A.

So I have connected my unit’s power supply to the converter, routed an electric cable from the converter’s output through the bike’s frame directly to the unit’s electro magnet and fixed this converter to my handlebar.

This way I can power on the converter, adjust it for maximum 12V and start riding on low current (0.100 A). If I want more resistance I will higher the current, until 5A which is the maximum supported by my unit. With the basic formula already provided here, you can estimate the % of resistance the unit is delivering.

If anybody is interested in some more detail on how I’ve done it please let me know, I can share some pictures.

Regards

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