How would I trigger a solenoid from a timer pulse, either from a 555 or the output of an electronic metronome?
Emphasis on cheap and easy. Small and portable (battery powered) also are big plus.
Basically the solenoid- triggered either from a 555 or headphone out of a metronome (which would be easier?) would tap the table (or other object) to the beat.
(I'd love to tape this to my drummers head!)