Found in a1967 Ferranti documentation, this circuit uses an operational amplifier from that time. The circuit uses a LDR as a sensor and has a null setting.
The transformer of this unit found in an old Japanese documentation can have 22 to 25 V of...
This JFET amplification stage was found in the April 1993 issue of Electronics Now. The input...
This circuit with two power transistors was found in Radio Electronics magazine from October 1960....