Posted on Oct 27, 2012 3764
The door opener derives its power from a 9-V battery. A momentary-contact switch, 52, is provided in the event that manual opening and closing is required. Relay Kl is a 9-V type and relay K2 is a 117`Vac latching-type, which automatically latches with the first burst of current and opens on the second burst. The gate lead of the LASCR is not used; a light source triggers the LASCR unit into conduction, causing current to flow in the coil of the relay.
That, in turn, causes Kl"s contacts to close, thereby energizing K2 (closing its contacts), and operating the garage door motor.