I am modernizing my car harness, and I am using a P Mosfet as a diode, powering the low beams. what will be the capacity for the P Mosfet in this application? the low beams draw about 8 amps, will an IRF9540N hold up?
Cheers
Cheers
I think it will hold up but make sure you have a good heat sink. Note that the on-resistance is about 0.2 ohms. That means, at 8 amps, there will be a voltage drop of about 1.6 V across this device. Leaving you with only 10.4 volts.I am modernizing my car harness, and I am using a P Mosfet as a diode, powering the low beams. what will be the capacity for the P Mosfet in this application? the low beams draw about 8 amps, will an IRF9540N hold up?
Cheers
Isd (source to drain current) is listed as -19 Amps. But GopherT's comments tell a better story. By the graph I see about 0.9 Volts but there probably are better choices out there.I am modernizing my car harness, and I am using a P Mosfet as a diode, powering the low beams. what will be the capacity for the P Mosfet in this application? the low beams draw about 8 amps, will an IRF9540N hold up?
Cheers
Browsing at Schottky rectifiers and MOSFETs rated at 20 Amps or so you are still going to have about 0.7 or 0.8 Volts lost across the rectifier. One of the other suggestions is a 100 Amp rated device. That gets your resistance down to milli-Ohms.I am modernizing my car harness, and I am using a P Mosfet as a diode, powering the low beams. what will be the capacity for the P Mosfet in this application? the low beams draw about 8 amps, will an IRF9540N hold up?
Cheers
Those certainly have a low ON resistance but I think they are all N-MOSFETs and you need P-MOSFETs.