This very low power amplifier is designed by Amperex for hearing aids. It is based on TAA370 which is not an integrated circuit that can be found today.
The circuit below was suggested by the Motorola Linear Databook of 1990. The component used is...
The circuit of the figure consists of a motor timer that can delay drives for up to 15 minutes....
We found this circuit in a 1960 Sylvania transistor manual. The relay can be 12 V and C1...