power seats controls w transistors

How's this..... I haven't shown the diodes.... I'm used to MOSFETs including a "freewheeling" diode (as shown in its circuit symbol), though not all include it. But is is best putting a (reverse biased) diode across the relay coil. (For the FET and other sensitive circuitry...) You can use an NPN transistor instead of the N-channel (MOS)FET - terminal GDS become BCE, and the resistor values will have to change. And you need a suitable transistor gain etc. Not sure what is meant by the "dual coil" relays - or is that just two relays in one housing?   (Great until one fails.) I think the 2N7002 should be ok (500mA?). As I said, I'd tend to use MJT3055 (the FET equivalent of the 3055 transistor; handles ~15-20A) or even bigger ones. The there is little question about current capability, and if I add another 2 FETs (4 per motor), I can get rid of the relay. A swede is a type of vegetable - similar to a turnip. (But I've never eaten the vegetable. Some Swedes taste like mice though....) And that Swede (he probably lives in Fitja) is on another forum. I don't think his ego and insecurity would last here. Alas no job for Wallander. As to Krister of Rolf.... I only remember the later character, though I saw the original in "After the Wedding" (Efter Brödloppet??) Ah - that's Rolf Lassgård. He's great! But Krister is superb. It's just a shame about the daughter.....

Now I have something to test. Thank you very much! I will build one of these to try it out and tell how it went.No reason not to try

You sure you want to use 2N7002 rather than a 2N7000? The 2N7002 is quite tiny, and unless you have real space constraints, you might find the 2N7000 much easier to work with. Somewhere the original suggestion of 2N7000 got switched over. I used BS170's with a bit better specs, but have a bagful of the 2N7000's because they were a bit less lower cost and basically equivalent.

I'd go big. Why not get 20A-80A capacity FETs instead of 0.5A when the prices are so similar? As I wrote (somewhere), I get 60A-80A MOSFETs for about $2 each and use them for everything.

Price and size mainly. Overkill is fine, but if it's just being used to drive a relay, 10 cents vs. 2000 cents, and the smaller size makes them easier to stash away. If you're stocking up you could always just get stockpile an assortment big and small, and use whatever's needed.

As I need about 40 transistors or MOSFET:s and 40 diodes the cost is a factor of course. I just tried a BC546B that was lying around at home and it does the work so even if I would prefer MOSFETS I will use something smaller if it works. Size is also important. I see your point though Oldspark. I will make a working model and tell how it went.No reason not to try

If you already have the relays and want to keep them, cool. Then 546s or whatever works. But in place of relays.....