Solid State alternative to relay, low latch V

What's a good (see: cheap and small) alternative to a relay?

Requirements: handle a decent amount of current at the gate (up to 4As) and have a low coil/latch voltage (triggered by MCU).

Thanks guys.

I found that Triac's can accomplish this, as it seems they can handle a high current, can be used as diodes to isolate flow, and have a low control voltage.

Basically, I am going to design a device to implement the AUTO feature of power windows in cars. My car has it auto down for the driver's side using a relay, but my sister's does auto up and down for all four windows.

In my car it works by keeping both motor leads on a constant ground, then depending on whether you need it to go up or down, removes the ground from one and applies +12Vs. I would use an MCU to detect a pulse (high for 1/2 a second) from the switch and then trigger the Triac to provide +12Vs to the line while disconnecting the ground (have to figure that out somehow) and then when detecting a change of resistance (again, gotta figure this out) cutting off the Triac.

Any suggestions?

LiquidKernel said:

What's a good (see: cheap and small) alternative to a relay?

Requirements: handle a decent amount of current at the gate (up to 4As) and have a low coil/latch voltage (triggered by MCU).

Thanks guys.

Click to expand...

Power MOSFET.

MCU can drive directly in most cases. You can get a suitable one for less than $1.00 US.