I have the following simple circuit. However, when I put the multimeter on the receiving end I'm always getting a current and I can't shut the gate, can anyone help please?

I'm using the following MOSFET: Infineon AUIRL1404Z N-channel MOSFET Transistor, 180 A, 40 V, 3-Pin TO-220AB

Power source is an 11.1V 5000mAh LiPo battery.


simulate this circuit – Schematic created using CircuitLab

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    \$\begingroup\$ You have no gate discharge resistor. Add a resistor 10-100k at the gate to ground, problem solved. \$\endgroup\$ Commented Oct 21, 2016 at 21:06
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    \$\begingroup\$ Resistor gate to source as el Captain says. \$\endgroup\$ Commented Oct 21, 2016 at 21:09
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    \$\begingroup\$ In your previous question you had a battery voltage of 22V, is that still the case? The mosfet you have has a max Vgs of 16V. \$\endgroup\$
    – Steve G
    Commented Oct 21, 2016 at 21:11
  • \$\begingroup\$ You can flip components in Circuit Lab. I cleaned up your schematic and added component / Power source info to it. \$\endgroup\$
    – Wesley Lee
    Commented Oct 21, 2016 at 21:24
  • \$\begingroup\$ @SteveG Yes previously I had two 11.1 LiPo's in serial, and a voltage regulator to step that down to 5v for the gate, but for simplicity I've ditched one of the batteries and am just using one, but I'm still having a constant current. \$\endgroup\$
    – Kevin Dark
    Commented Oct 21, 2016 at 21:29

1 Answer 1


enter image description here

Shunt Vgs with R1 to turn off. Never leave floating.

Also , FYI, Keep power + and return - paths close together as in paired wires or twisted wires and never in a large loop as shown in a "logic diagram".

  • \$\begingroup\$ Great! Thank you, I'll try that. Incidentally, I know you suggest a 10kohm resister, but you couldn't link to it on rscomponents.co.uk for me could you please? Just so as I get the right thing... :) \$\endgroup\$
    – Kevin Dark
    Commented Oct 21, 2016 at 22:05
  • \$\begingroup\$ uk.rs-online.com/web/c/passive-components/fixed-resistors/… cheapest will work if you followed my advice \$\endgroup\$ Commented Oct 21, 2016 at 22:12

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