Hi, another newbie with probably a stupid question but fingers crossed.....
I'm trying to switch on a horn. A remote button is pressed, activates an rf transmitter, the receiver then activates a relay and the horn sounds. The rf side works fine, but if I connect the horn it continues to sound when the button is released. If I use a bulb or buzzer etc it works perfectly - eg relay goes off when the remote button is released. The horn is 12VDC, drawing about 7A. The relay is rated at 20A. Relay coil is 12V too (separate supply to horn). Can any one suggest why this happens only with the horn and not a buzzer, and how to overcome it?