This car alarm was found in a 1965 General Electric manual. The SCR can be commonly used with the TIC106 and sensors are placed in the doors using the existing courtesy light switches.
This fast trigger circuit allows the counting of up to 300 pulses per minute. The circuit is from...
This intercom uses transistors from the 60s. It was found in a Japanese publication at the time....
This circuit is from an old publication from the 90s, but it can be adapted to operate with LEDs....