• Re: (accidentally) shorted a mosfet's drain and source

    From Michael Darrett@21:1/5 to Michael Darrett on Mon Jun 13 12:43:02 2022
    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

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Michael Darrett@21:1/5 to All on Mon Jun 13 12:35:31 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

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Dan Purgert@21:1/5 to Michael Darrett on Tue Jun 14 09:58:30 2022
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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.


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    --
    |_|O|_|
    |_|_|O| Github: https://github.com/dpurgert
    |O|O|O| PGP: DDAB 23FB 19FA 7D85 1CC1 E067 6D65 70E5 4CE7 2860

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Dan Purgert@21:1/5 to Dan Purgert on Tue Jun 14 10:19:02 2022
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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).


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    --
    |_|O|_|
    |_|_|O| Github: https://github.com/dpurgert
    |O|O|O| PGP: DDAB 23FB 19FA 7D85 1CC1 E067 6D65 70E5 4CE7 2860

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Phil Hobbs@21:1/5 to Michael Darrett on Tue Jun 14 09:20:03 2022
    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

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Michael Darrett@21:1/5 to Phil Hobbs on Tue Jun 14 07:20:34 2022
    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

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)