This circuit was obtained from a Radio Electronics in February 1965. The circuit uses two transistors from the time and can be created with modern equivalent transistors.
This is a different circuit for a component from the past, the zirconium arc lamp used in...
This circuit uses a FET to drive an LED with constante currente. The current up to 20 mA can be...
This circuit uses a phototransistor as sensor. The changes in the resistance of the transistor,...