As the title says - I can see a-lot of people doing this on forums etc.
This being: the omission of galvanic separation.
I need to PWM a 24V DC fan fan from my micro-controller .
I have already sorted the power supply for the fan, but i was digging through my box and found a suitable MOSFET that will be more than open enough for my use at 4V.
Though, if I hook the PWM output up to the gate terminal with a suitable series resistance and resistor to source - then i will need to connect the source of the MOSFET controlling the fan to VEE of my micro-controller board.
This means that one of the terminals of my power supply will be connected directly to my micro-controller, which has me questioning weather or not i will need an opto-coupler.
The schematic below shows my circuit configuration. (two zener diodes are 12V to give 24V)
If i were to use an opto-isolator, then I would need to generate another DC level at 5V for gate driving of the logic level FET.Which is of course MORE work, though i would prefer that to a blown Micro-controller.
A voltage divider across the 24V DC would suffice for providing 5V at <1mA that the FET needs, this has just occurred to me.
Any insight on the matter would be more than helpful.
Thanks!
This being: the omission of galvanic separation.
I need to PWM a 24V DC fan fan from my micro-controller .
I have already sorted the power supply for the fan, but i was digging through my box and found a suitable MOSFET that will be more than open enough for my use at 4V.
Though, if I hook the PWM output up to the gate terminal with a suitable series resistance and resistor to source - then i will need to connect the source of the MOSFET controlling the fan to VEE of my micro-controller board.
This means that one of the terminals of my power supply will be connected directly to my micro-controller, which has me questioning weather or not i will need an opto-coupler.
The schematic below shows my circuit configuration. (two zener diodes are 12V to give 24V)
If i were to use an opto-isolator, then I would need to generate another DC level at 5V for gate driving of the logic level FET.
A voltage divider across the 24V DC would suffice for providing 5V at <1mA that the FET needs, this has just occurred to me.
Any insight on the matter would be more than helpful.
Thanks!
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