Oznog
Active Member
I have been toying with the idea of replacing the diode battery isolator on my car with a MOSFET implementation. With a 160 amp alternator and some extremely high loads that thing can drop like 150 watts or more. It says it's rated for that high a current but the heatsink hardly looks sized for that. And the thing drops over 1v under load so the alternator is working harder than it should.
I'd like to use an op amp to drive a MOSFET- or several- to make a cooler running device with little voltage drop. The op amp is there so that we can just amplify the drop across the drain-source, if it's positive the MOSFET needs more drive. This can reduce the loss to something comparable to the op amp's offset voltage.
The thing I worry about here is they still need to be sinked, but a failure of the insulator would be catastrophic to say the least. This is a very high vibration, high heat environment. Fuses are quite large and expensive and it is very tricky to keep their resistance low. I know and love silicone pads, is there any truly bulletproof space-age insulator out there that would be better for such a critical app?
I'd like to use an op amp to drive a MOSFET- or several- to make a cooler running device with little voltage drop. The op amp is there so that we can just amplify the drop across the drain-source, if it's positive the MOSFET needs more drive. This can reduce the loss to something comparable to the op amp's offset voltage.
The thing I worry about here is they still need to be sinked, but a failure of the insulator would be catastrophic to say the least. This is a very high vibration, high heat environment. Fuses are quite large and expensive and it is very tricky to keep their resistance low. I know and love silicone pads, is there any truly bulletproof space-age insulator out there that would be better for such a critical app?