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Jrk G2 24V 21 Driving wheelchair motor blown

Hi,

I’m position controlling a 250W 24V wheelchair motor and have blown two of these boards while testing under no load RC input. It happens when repeatedly commanding the motor to quickly reverse direction. Is there a way to mitigate the resulting voltage spikes other than board settings. Keeping the power leads short and twisted, ferrite choke, capacitor?

Thanks

Hello.

Oh no! I am sorry to hear about your Jrks. I suspect the biggest thing you can do to limit these voltage spikes is reduce the Jrk’s max acceleration and deceleration, plus its hardware current limits.

As for other things you can do, shorter power leads and additional capacitors would probably help. (Ferrite beads and twisting wires are more effective for reducing high frequency noise like EMI.) Using something like one of our shunt regulators might also help; the 26.4V, 2.80Ω, 15W model (item #3775) would probably be the most appropriate one we have for your application. Please keep in mind though, our shunt regulators are only designed for clamping occasional short (up to tens of ms) pulses. If you decide to try one, I strongly recommend looking at the spikes your system is experiencing with an oscilloscope first so you can see how high and long they are. I suggest doing these tests with a lower supply voltage to avoid damaging more units.

- Patrick

Thanks for the information I’ll look into the shunt regulators. I have been using this motor/jrk G2 combination for about a year now and got lucky with not blowing any. I happened to set up each controller with accel/decels below ten and a 300ms pause before reversing direction to fit my needs at the time. They’ve been working fine.

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