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(accidentally) shorted a mosfet's drain and source

Started by Michael Darrett June 13, 2022
For a project I noticed my Arduino PWM pump controller (basically just an Arduino, MOSFET, and protection diode) was behaving oddly, so I powered the pump directly from the 12V power supply, turning it off and on as needed manually.

I looked more closely at my breadboard, and noticed the drain and source were touching.  The circuit had been running for a few minutes this way.

Did I damage my MOSFET, or is this ok?

Thanks,

Michael
On Monday, June 13, 2022 at 12:35:34 PM UTC-7, Michael Darrett wrote:
> For a project I noticed my Arduino PWM pump controller (basically just an Arduino, MOSFET, and protection diode) was behaving oddly, so I powered the pump directly from the 12V power supply, turning it off and on as needed manually. > > I looked more closely at my breadboard, and noticed the drain and source were touching. The circuit had been running for a few minutes this way. > > Did I damage my MOSFET, or is this ok? > > Thanks, > > Michael
It's a PSMN022-30PL, driven by a 12V, 3A power supply, if it matters. Thanks, Michael
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Michael Darrett wrote:
> On Monday, June 13, 2022 at 12:35:34 PM UTC-7, Michael Darrett wrote: >> For a project I noticed my Arduino PWM pump controller (basically >> just an Arduino, MOSFET, and protection diode) was behaving oddly, so >> I powered the pump directly from the 12V power supply, turning it off >> and on as needed manually. >> >> I looked more closely at my breadboard, and noticed the drain and >> source were touching. The circuit had been running for a few minutes >> this way. >> >> Did I damage my MOSFET, or is this ok? >> > > > It's a PSMN022-30PL, driven by a 12V, 3A power supply, if it matters.
That's an N-channel FET, so having gate shorted to source (i.e. ground) simply means it'll never turn on. I'd be more concerned that the short damaged the arduino's pin. -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEE3asj+xn6fYUcweBnbWVw5UznKGAFAmKoW9YACgkQbWVw5Uzn KGDEdhAAq7n5otnpfBGeNklnazZaMy5h6S40vcB+oOY+lSK6kvKrcJBTu5Q4Yj0l ZPske+rGv+X17uBtq6wTtyz9esdNXZORfPNolZLvPEbUqb9V/+g5oDf1HgLGOFca MGkTlTfhK50/Shn7IkzBRXYn7z8l5aVt39ZkrCXaLHMuAMdhniBY/6WNjhQhFaqK zf27pufxDMOdCELZL5vb3muf3v20UIMJu1eRlke2itDrI35aQ8wH+ddFp2CGS/Nb z7VEw0SIhH6KPxfGtMwqRC4I0RT5ymdLHtuIbYMV1SqYl9GUB25hZ8gyTwhIo3JK ixDEns5CihXJg/EOD3qHElJVgwCf3TUbRkeLMnG3la/Wno7ejrhPt1btLQSQpWz6 afflqYTDleErI1xcohnyITBbmsrLbsi6wyCV3lBRfnPLjs9mqbJxfOlZ/fEdaxVE OioRubuDmamWd2XmN3KPcUepo4TscpZ+DSLh+AA6XoSF7hwP3AeCzyu8oVVUJ3Vw V5zwHXWN7HOwznHFD86QWBcROZPOOcf2btu48AFDhTPDaB7/6dWexgb1fNmS+AyF S++/zVQJLH9bEoddCa/5RtiqwsmL2nlJW0AaZuTfpY95Vu+jXyYV7uDMXVUjNWD2 t7U1zN/T2hJhWtJY0oAH+WVBfuYdTeP6olNBrZB8ME3nCFtH978= =x/nq -----END PGP SIGNATURE----- -- |_|O|_| |_|_|O| Github: https://github.com/dpurgert |O|O|O| PGP: DDAB 23FB 19FA 7D85 1CC1 E067 6D65 70E5 4CE7 2860
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Dan Purgert wrote:
> > Michael Darrett wrote: >> On Monday, June 13, 2022 at 12:35:34 PM UTC-7, Michael Darrett wrote: >>> For a project I noticed my Arduino PWM pump controller (basically >>> just an Arduino, MOSFET, and protection diode) was behaving oddly, so >>> I powered the pump directly from the 12V power supply, turning it off >>> and on as needed manually. >>> >>> I looked more closely at my breadboard, and noticed the drain and >>> source were touching. The circuit had been running for a few minutes >>> this way. >>> >>> Did I damage my MOSFET, or is this ok? >>> >> >> >> It's a PSMN022-30PL, driven by a 12V, 3A power supply, if it matters. > > That's an N-channel FET, so having gate shorted to source (i.e. ground) > simply means it'll never turn on. I'd be more concerned that the short > damaged the arduino's pin.
*sigh* totally misread as gate-source, not drain-source. (note to self, coffee before Usenet). A drain-source short is more likely to ruin your power supply, not the fet (the leads will act as wires, no current will flow through the FET itself). -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEE3asj+xn6fYUcweBnbWVw5UznKGAFAmKoYKkACgkQbWVw5Uzn KGCDqw/9GjOcndsw8nMq7RI5pHaqUpSrz+iL1sq0BNwcA/WKnwa8+tsbDEGZbcDU JsrtdjDBrlgWEte5ODbiMIw1g0SNGaWjGxIMlQLweww/s+h6O69Cyxe45BlL/arL 6iaaI+hY/pELki5Hlk8ZeFI8bA4Z7owjL42J/FTXHdqoMDlxW7enbG9lPlRCvLPN j2ZxjrACoOF437SMCvLIDV+GLz5XxSsN1suUR/F5pfvSPAXMqp8xPcw/0wkuj1dK hzkoRC2VYqfFyL6dqR41daz5kH2pluSl67k9pEDLAggWOcUfaOisHnjnS2xNwfFT hwXEk6kwI7wobW1qXBhdkTON4/QHZY7rCEclFSGz+pns8xBOlnE2yhE7MIjyIv0p t2J39MHfH6lu4ruSQBk0FAneAmSkIiN0qGQ2fcbhJ4Z0gkzCJAe+W1XtPcddxcqP 9LQnPVTllYw3iQjh0awJNSMQXcLXOdX+lrrl3GJBCYv1k600q+ZtSt9ry0lBCjQG ZUP8UCQR8Be5kDkRHb5MRu6JxeU1LxrrshYI53y1kx0tkfvY5tzFlqcCzj5m3Bc6 Q31cLteHRKlIjXSXzqm8/PeAICOMCEXrH90JbSkozZf5wAK4M0fk6zUCVmyfAxfj PECwoeE1wiEKXCzXqciwkje442lHA/C2uD6A+T3LjqlVjtsa1SQ= =B1+x -----END PGP SIGNATURE----- -- |_|O|_| |_|_|O| Github: https://github.com/dpurgert |O|O|O| PGP: DDAB 23FB 19FA 7D85 1CC1 E067 6D65 70E5 4CE7 2860
Michael Darrett wrote:
> On Monday, June 13, 2022 at 12:35:34 PM UTC-7, Michael Darrett wrote: >> For a project I noticed my Arduino PWM pump controller (basically just an Arduino, MOSFET, and protection diode) was behaving oddly, so I powered the pump directly from the 12V power supply, turning it off and on as needed manually. >> >> I looked more closely at my breadboard, and noticed the drain and source were touching. The circuit had been running for a few minutes this way. >> >> Did I damage my MOSFET, or is this ok? >> >> Thanks, >> >> Michael > > > It's a PSMN022-30PL, driven by a 12V, 3A power supply, if it matters. > > Thanks, > > Michael >
Should be OK from an electrical POV--the pump limits the current. Of course, something may have got damaged by whatever mechanical trauma caused the short. Cheers Phil Hobbs
On Tuesday, June 14, 2022 at 6:20:13 AM UTC-7, Phil Hobbs wrote:
> Michael Darrett wrote: > > On Monday, June 13, 2022 at 12:35:34 PM UTC-7, Michael Darrett wrote: > >> For a project I noticed my Arduino PWM pump controller (basically just an Arduino, MOSFET, and protection diode) was behaving oddly, so I powered the pump directly from the 12V power supply, turning it off and on as needed manually. > >> > >> I looked more closely at my breadboard, and noticed the drain and source were touching. The circuit had been running for a few minutes this way. > >> > >> Did I damage my MOSFET, or is this ok? > >> > >> Thanks, > >> > >> Michael > > > > > > It's a PSMN022-30PL, driven by a 12V, 3A power supply, if it matters. > > > > Thanks, > > > > Michael > > > Should be OK from an electrical POV--the pump limits the current. Of > course, something may have got damaged by whatever mechanical trauma > caused the short. > > Cheers > > Phil Hobbs
Thanks Phil and Dan. On my breadboard, the wires going to the drain and source had too much insulation removed before going into the breadboard, and they simply crossed. After noticing, I moved them further away from each other. I was more worried about whether I could rely on the mosfet again than in the power supply, but thanks Dan for the caution that the power supply could be damaged. It's just a run-of-the-mill power supply which (I think) powered a cable TV box or something similar, which has long since been lost. Have a great one! Michael