burnt Roboclaw 2x7A repairs

General discussion of using Roboclaw motor controllers
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Alex
Posts: 2
Joined: Sun Feb 28, 2021 9:52 am
burnt Roboclaw 2x7A repairs

Post by Alex »

Hello,

Because of my carelessness I reversed +/- and burned 2x7A. Actually, the RC is not completely dead, it is detected by PC, flashes LEDs, etc. The visible damage are two current sense resistors, which burned almost to ashes.
I am going to replace them and see if the problem will resolve. However, I'll appreciate an answer to a couple of questions:
1. What's the original part? The other unburned board has a 10L0 marking, which is 0.01 Ohm. Size is 2512, I suppose. What is its wattage and precision? The local distributor has CRA2512-FZ-R010ELF
https://www.digikey.com/en/products/det ... FZ-R010ELF
on hand - would it suffice?
2. Is there anything else to check after such shock?

Kind regards,
Alex
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Basicmicro Support
Posts: 1594
Joined: Thu Feb 26, 2015 9:45 pm
Re: burnt Roboclaw 2x7A repairs

Post by Basicmicro Support »

The controller is not designed to survive reverse power. It will have instantly damaged the mosfet drivers.

If you still want to try, they are as you determined, 2512 10mOhm. They need to be a minimum of 2watt.

The a4940K chips are almost certainly dead as well.
Alex
Posts: 2
Joined: Sun Feb 28, 2021 9:52 am
Re: burnt Roboclaw 2x7A repairs

Post by Alex »

Thank you very much for a reply. I've ordered a replacement board, but will try to restore that one too. Unfortunately a4940 are already discontinued, so we'll see if we have luck. Only one chip has a burn mark, so probably it's not that bad.

Generally, you have a very nicely designed board at a right price, no complaints accepted if customer is ass-handed.

Kind regards,
Alex

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