/diy/ - Do It Yourself

I was pointed here from /g/ from an anonymous poster

I'm looking for something but I don't know what it is yet

I'm currently using mechanical relays controlled by an arduino to drive my thing, but they're too power hungry and too slow for my liking
had a look at solid state relays but they only seem to work with AC and tap into the output load, of which there is less than 1.5v, so not ideal

so is there some miracle component that will satisfy these criteria?
I'm an idiot with this stuff in case that wasn't obvious