This is a photograph of the transistor based Motorcycle Alarm No.4
. The circuit features a timed output and automatic reset. It can be operated manually using a key-switch or a hidden switch. By adding an external relay - it will set itself automatically every time you turn-off the ignition. It's easily adapted for a 6-volt system - so it will protect your "Classic Bike". And - because its standby current is zero - it won't drain your battery.