We found this circuit in the Radio Electronics magazine of May 1977. The transformer voltage is 6 + 6 V, and the current depends on the zener diodes and is in the order of 100 to 200 mA.
We found this circuit in a Mullard manual from 1960. The transistor is a phototransistor of the...
The circuit that gave rise to this configuration was found in a magazine of the 1980s with the...
This oscillator with FET was found in Popular Electronics from the 90s. This traditional...