This circuit for old flashes with xenon lamps was found in a Radio Electronics magazine from June 1966. The sensor is a photoelectric cell from the time. Power is supplied by a 9 V battery.
This circuit is the conventional configuration of a negative regulator for a current up to 1 A and...
We found this circuit in the 1982 SGS Linear Integrated Circuits manual. The L78xx is equivalent to 78xx...
This timer activates a relay after a time interval of up to 15 minutes has elapsed, starting from...