I am a musician. There is a metronome out called a body metronome and uses a vibrating clip rather than a speaker - so the musician "feels" the beat. *very* cool thing. Anyways they are $120 and I can make one way cheaper.
I have a couple of eletronic metronomes with ear phone jacks. These emit a square wave(ish) at 5Vpeak for about 5ms duration. I also have scavenged a cell phone vibrator motor from an old phone that takes about 3.5VDC max. I tried connecting the two thinking that the load from the motor would sag the voltage, but nothing happened. So I am guessing one of a few things. I need more current, I need a longer on time, I need a little less voltage.
So... I am thinking I should have a sperate power source for the motor - a rechargeable lithium will do. And use a transistor to control the power to the motor, and the transistor can be triggered by the metronome. However, I am unsure about any supporting components or the right spec for the transistor. Also I am unsure how I can increase the on time (although I am not sure if I even need it)
thanks for the help.