As above - need to flash two bike 12V 21W indicator bulbs (in parallel) in an environment with severe vibration - I have tried two makes of mechanical (bi-metallic strip) units which are prone to vibration upsetting the flash rate. So I want to buy/make an electronic flasher. The flasher unit is a two terminal device in series with the load - i.e., the passing current heats up the strip within. I am not sure there exists a two terminal electronic unit, although I assume adding an earth would not be unacceptable, but I don't really want to have to rewire the bike to accommodate e.g. a 555 timer circuit driving a FET or Power Transistor.
Anyone any suggestions ?
Apologies if a bit OT - it is DIY though !
Nick