Found in a 70s RCA manual, this circuit uses transistors from the era. Equivalent types can be used such as TIP31 for Q1 and BD135 for Q2.
We found this circuit in a technical documentation from the 70s. It can be implemented with more...
We found this shield circuit in a 1991 technical documentation. The phototransistor can be...
This circuit was obtained from a Radio Electronics from October 1963. The 4 transistors must be...