Hello everyone. I've got a current limiter circuit that I'm working on here that "almost works". I've attached a schematic below.
The circuit sends 50 VDC to an external load whose resistance varies. The incoming current first goes through a current sensor whose output signal goes to a microcontroller (not shown). The microcontroller evaluates the current measurement and adjusts an analog output to between 0 and 10 volts. This control voltage is connected to the bases of six MOSFET transistors to throttle the current that goes through them.
When I make the microcontroller send different control voltages, the output current changes accordingly, so it would appear the the current is being limited like I am hoping. The problem is that I keep frying the MOSFETs. I'm putting 30 amps through the external load and the MOSFETS should be good for 52A / 1250W each. Since I've got six of them in parallel, I don't get why I'm frying them. I'm not an electrical engineer so I may be approaching this in a completely wrong way. Any suggestions?
Thanks,
Ron
The circuit sends 50 VDC to an external load whose resistance varies. The incoming current first goes through a current sensor whose output signal goes to a microcontroller (not shown). The microcontroller evaluates the current measurement and adjusts an analog output to between 0 and 10 volts. This control voltage is connected to the bases of six MOSFET transistors to throttle the current that goes through them.
When I make the microcontroller send different control voltages, the output current changes accordingly, so it would appear the the current is being limited like I am hoping. The problem is that I keep frying the MOSFETs. I'm putting 30 amps through the external load and the MOSFETS should be good for 52A / 1250W each. Since I've got six of them in parallel, I don't get why I'm frying them. I'm not an electrical engineer so I may be approaching this in a completely wrong way. Any suggestions?
Thanks,
Ron
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