Found in a 1965 Electronic Design, this circuit divides the frequency of a cascaded signal using unijunction transistors. The bipolar transistor supports an equivalent. The shock is 470 mH.
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....