Obtained from a 1969 neon lamp documentation, this circuit shows how to assemble an indicated circuit triggered by - 24V pulses. The neon lamp is of the era type.
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....