This circuit was found in the 1967 RCA SCR manual. The circuit generates approximately 300 V at a frequency of 1 kHz. The components are from the era.
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....