Hello everyone, I am a completely newbie who is trying to create a project that allows me to fade a LED downlight using a mosfet. I am currently using an Arduino Uno board and a external downlight power supply with an estimated output voltage of 50Vdc. Would someone be able to recommend on what logic level N Mosfet to use for such case?
Show a rough schematic. With 50 volts and a P channel mosfet on the high side, it does not need to be logic level, however you'll need an additional NPN transistor.
EDIT
Ensure it is clear what power is required and some indication of the PWM frequency for the fading.
The DMT10H025LK3
This is the schematic that I will be using which I got from another forum. The project that he is doing is quite similar to mine. Just that I am not able to determine the MOSFET to use for my case.
The DMT10H025LK3
Thanks for your help! I would like to understand how you managed to determine this model of MOSFET for the project? sorry if I am asking a noob question. Kind of curious over here
You need a MOSFET with a Drain-Source voltage greater than 60V, this one is 100V.
Without any special heatsink this MOSFET has a maximum power dissipation is 2.7W
This MOSFET has a maximum Rds(on) of only 0.0437 ohms with a gate voltage of 4.5V.
For a current of 5A the MOSFET power dissipation would be 5^2 * 0.0437 = 1.1W
1.1 is less than 2.7 so power dissipation is OK as long as your LED requires less than 5A
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Got it! Thank you so much!
The data sheet is here https://www.mouser.ch/datasheet/2/115/DIOD_S_A0006645051_1-2542856.pdf
The mosfet gate current limiting resistor should be 150 Ohms and the gate pull down resistor 10k to minimise spurious switching on power up.
The PWM frequency on pin 9 is 490Hz so switching losses will be negligible.
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FYI
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