I am trying to use an arduino to control a relay which will connect 18V DC to a cordless drill. I converted a charger into a battery dock and gutted an old battery pack to allow power into the drill via a couple of connectors. The idea is to physically pin the trigger of the drill down the turn it on and off via a relay in between the drill and power source.
I have a cheap eBay solid state relay designed for AC/20 amp and DC 3-30VDC input. If I put it inline and apply power to the relay then pull the trigger on the drill it works great. If the trigger is already pulled on the drill when the relay is powered however it does not work.
Is this due to the relay being designed for AC?
Can anyone suggest a way to resolve this or a relay that would work?