Suggested by General Electric in 1965 documentation, this circuit controls the current at a load from half to maximum power. The circuit is for loads up to 900 W with the indicated components.
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....