I bought an electric winch. Specifically an EWK 2000, and I would like to design a simple controller for it with relays. Just to be on the safe side, I believe I should use some capacitors, and not wire it up directly to a 12v battery. The question is, how can I calculate the size of the capacitor to use?
According to the user manual, the motor uses 25A at 12V when pulling 500 lbs, and I don't think I will ever lift more than that (Even that the winch should be good for up to 2000 lbs.).
Yes. Hook it directly to the battery to test the thing. If it needed capacitors, the factory would have sent them. Follow the included instructions and you will be ok. Keep fingers out of the mechanism!
It wouldn't be a very good winch if it didn't come with a capacitor if it needed one.
But you will need a fairly heavy duty relay that can handle the full power of the motor..
Motors draw full power to get up to speed at every start up so you can't use the 25A figure. It requires a relay that can handle the full Amp rating plus a little for insurance.
A good cheap source for this type of relay is an old ford starter solenoid.
The solenoid is 12v so you will need a mosfet and preferably a optocoupler circuit to use it with an Arduino.