Solid State Relays for Door Lock

Lately I've been working on a solid state module to replace the relays used for the door locks in the GM5. Finally the prototypes are done and ready for some testing.

Update 2009-06-03: I had the solid state relays in my car for a couple weeks and at first everything was fine, but, the driver's door lock would sometimes not lock or unlock all the way. I've been noticing for a while (even before the solid state relays) that that door seemed to operate more slowly than the rest. I believe that the actuator is starting to go bad. I put back my original GM5 with the good ole mechanical relays and it works again. One of these days I want to put a current probe on the actuators for each door and measure the current profile to see if that driver door actuator consumes more current. I have not put the solid state relays back in my car because I'm going to try a new set of MOSFETs with lower On resistance. The ones I originally chose where cheap and decently good. This time I bought some really good ones that cost over twice as much. I also have new boards coming. The new ones are 4 layer with power and ground plane, silkscreened, soldermasked and slightly relaidout with thicker traces everywhere.

This is a picture below if of my original solid state relay module. Four of these modules are required to replace the two V23084-C2001-A303 relays since each relay contains two independant relays. And each module contains 2 MOSFETs so that's a total of 8 MOSFETs per system.

The next two pictures show the four solid state relay modules installed on my spare GM5 module.

I currently don't have plans to offer these up for sale. This was mostly done for fun. This is not anything new. BMW uses solid state switching on their higher end cars like the 5 and 7 series.

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