Sizing MOSFET Heat Sink
12 volt solid state relay. Parallel MOSFETS opto coupler driver. MOSFETS are 100 ampere 3 milliohm 50 volt. TO220 case. Ham Operators.... Any ideas for proper heat sink selection? Individual ...
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GOOD GRIEF! Thank you (!) (!) (!)
For the download.
One of the projects is for an extreme baffled wireless remote switch that is going to handle 200 amperes. This will allow me to O/C my battery bank from a 30 meter distance. Chop power to the inverter.
Engineers tend to design things for the bench. Where it's a comfortable 20C. This thing is probably going to see 50C ambient, and that does not give me much room to work with.
The heatsinks are extra thick anodized. Nylon bushings, screws and nuts to hold things together while the epoxy cures. I do not know if the infinitesimal mass of arctic silver would generate enough capacitance to affect the MOSFET. This is why I am using isolated heat sinks and the anodizing should offer enough insulation to isolate the MOSFET, totally.
Next is a search for conformal coating that is superior to the stuff I used to use when dinosaurs roamed the earth. The heatsinks and even the opto-couplers of course have to remain clean but underneath the PCB gets coated. Same for wire junctions.
I am going to use 3ns hyperfast freewheeling diodes, plus TVS for protection. I also found a source for .2 watt (oil immersed sealed ball bearing) fans.
Things have to be engineered rather overkill I'm afraid. There is no "oops, good golly, well, time to run down to the Radio Shack Store" (9 days travel).
I've ordered up a variety of materials. The above is the most extreme duty.
Going off-grid and employing wireless operation, for everything but the A/C.
For the download.
One of the projects is for an extreme baffled wireless remote switch that is going to handle 200 amperes. This will allow me to O/C my battery bank from a 30 meter distance. Chop power to the inverter.
Engineers tend to design things for the bench. Where it's a comfortable 20C. This thing is probably going to see 50C ambient, and that does not give me much room to work with.
The heatsinks are extra thick anodized. Nylon bushings, screws and nuts to hold things together while the epoxy cures. I do not know if the infinitesimal mass of arctic silver would generate enough capacitance to affect the MOSFET. This is why I am using isolated heat sinks and the anodizing should offer enough insulation to isolate the MOSFET, totally.
Next is a search for conformal coating that is superior to the stuff I used to use when dinosaurs roamed the earth. The heatsinks and even the opto-couplers of course have to remain clean but underneath the PCB gets coated. Same for wire junctions.
I am going to use 3ns hyperfast freewheeling diodes, plus TVS for protection. I also found a source for .2 watt (oil immersed sealed ball bearing) fans.
Things have to be engineered rather overkill I'm afraid. There is no "oops, good golly, well, time to run down to the Radio Shack Store" (9 days travel).
I've ordered up a variety of materials. The above is the most extreme duty.
Going off-grid and employing wireless operation, for everything but the A/C.
