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Suggested mosfets for halogen lamps (DC)
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Please be positive and constructive with your questions and comments.

Suggested mosfets for halogen lamps (DC)

by richms on Wed Aug 04, 2010 9:52 am

Is there a logic level mosfet that will be happy doing PWM on 12v at about 5 amps?

Want it to be on enough with only 5v that it doesnt get crazy hot, as I will only have a small sealed alloy box to use as the heatsink, and it will be doing several channels so several in the one box.

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Re: Suggested mosfets for halogen lamps (DC)

by adafruit on Wed Aug 04, 2010 1:08 pm

any power MOSFET will work - but keep an eye on power dissipation and get a heatsink!

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Re: Suggested mosfets for halogen lamps (DC)

by richms on Thu Aug 05, 2010 1:38 pm

I have tried a couple of random ones and they have too much voltage drop across them.

Will do a pull up resistor and a bipolar to turn off next time I am out getting stuff. Was hoping for a simpler one. All the ones sold as logic level seem to have a max current of only a couple of amps, and I need 5 for each lamp.

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Re: Suggested mosfets for halogen lamps (DC)

by adafruit on Thu Aug 05, 2010 3:50 pm

get one with low RDSon - that determines how much voltage is dropped. get lowest you can

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Re: Suggested mosfets for halogen lamps (DC)

by zener on Fri Aug 06, 2010 2:10 am

IRLZ44PBF

That ought to work. Keep in mind the 25 degree C currents they put on the datasheets are fantasy numbers. Divide those by about 8 to get a real-world continuous current capability, give or take.

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Please be positive and constructive with your questions and comments.