DC Mabuchi 370 EMI : resets Arduino through MOSFET

Other Hardware General Electronics
1

Hi everyone,

So I replaced my fried 43A H-Bridge (43A H-Bridge fried? Yes/No? How to repair? - #30 by marc426 - General Electronics - Arduino Forum) even though I wasn't sure it was but anyway...

Instead I'm using a Tinkerkit MOSFET module which, by the way, doesn't use an IRF520S but in my case, a IRF3806 which gives 15,8mOhms RDSon @VGS=10V so much better than the original.
It drives a fuel pump comprising a Mabuchi 370

Now, I didn't bother using the library and I'm feeding it PWM through analogWrite instead.

When I test it with a simple sketch such as fading, it does work fine BUT when I include it in my more complex sketch (2 small sketches using an identical function to read serial react differently... - #6 by marc426 - Programming Questions - Arduino Forum), as soon as it starts (wether with a ramp from PWM=0 to 255 or directly 255), my sketch loses track and acts as If I had restartesd (as if millis() was put to 0) the sequence.

NOT the Arduino, it doesn't reset in itself but the sequence goes back to the start, EVERYTIME.

Am I seeing a bad case of EMI / Power decoupling? How could I find a (cheap?) solution to this?

Thanks for the help!

Marc

2

Anyone? :slight_smile:

Or maybe I should post it in Motors? Didn't know where to put it as it's about the Arduino AND the motor...

3

As always with a hardware issue you have to show us your hardware... schematic?
photo? What are the various supplies? What's powered from what? What's a Mabuchi370
(ie post links to data, not just names - you've already searched, don't make us all do it please).

And provide both sketches.

4

marc426:
It drives a fuel pump comprising a Mabuchi 370

When driving motors or inductive load you should use a snubber circuit at the mosfet output, are you?

5

Yes absolutely.

I mean, there is a freewheeling diode on the MOSFET module, that's what we're talking about, right?

6

Again we need to see what you have, full sketch, link to data on that MOSFET
module, a diagram of how you have it all connected and details of how everything
is powered...

7

marc426:
Yes absolutely.

I mean, there is a freewheeling diode on the MOSFET module, that's what we're talking about, right?

Google for snubber circuit, it's a capacitor in series with a resistor and it is used in ac circuit, that diode you mentioned does have another purpuses.