Can I use a IRL540N Mosfet to switch a 0.25A - 1.00A / 12V circuit?


I know that this is a noop questions. But each and every one has to start at one point :wink:

I want to switch a PTC heater on/off based on a programmed logic. The heater runs at 12V, uses up to 8W
with 1A if it heats up and after that is drops down to about 0.25A. I have a IRL54ON Mosfet and would like to use it. So my question is, if I can use the Mosfet for this.

An alternativ might be a

  • 2N2222 but this only takes up to 800mA.
  • Relay (what I did'nt like to much because of the clicking noises
  • SSR thatdoesn't work because of the DC/AC problem

Any hints how to build the IRL540N / 2N2222 circuits (best as a breadboard example) are very welcome.

I have a IRL54ON Mosfet and would like to use it. So my question is, if I can use the Mosfet for this.

Yes, the "L" version is logic level, and can be used with a 5volt Arduino.
Use the first circuit on this page.
If a resistive heater is switched, then the diode can be omitted.

A 2N2222 shouldn't switch more than ~400mA (with 20mA base current), so can't be used.

Thanks - I try to do my best to transfer it to a breadboard. Still struggling with such plans.

Be sure to understand that the n-channel MOSFET needs to be used as a low-side switch, so 12V supply goes to
heater, and the other heater lead to the drain of the MOSFET.
Source of MOSFET to ground, gate to Arduino pin.

Add ~ 10k resistor from gate to source on the MOSFET so its held off while the Arduino starts up / resets.

A 150ohm resistor or so in series with the gate is recommended to reduce current spikes pulled from
the Arduino pin.

And lastly MOSFETs are static sensitive so take precautions handling them - never touch the gate pin
unless you already have contacted the source pin, and never wear nylon shirt when doing electronics,
natural fibres only. A proper anti-static wristband is recommended.

12VDC can be switched as Q3 is showing.
Replace load with your heater.


BTW, when plugging a TO220 case into a solderless breadboard, twist the leads so they run in line with the pins (this helps to prevent springing the connectors).