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.
In this oscillator a phase shift network formed by C1, C2, C3 and R1, R3, R4 determine the fase...
For inductive loads we have the configuration shown in the figure. Note that the optical coupler...
This circuit was found in the Linear Applications Handbook by National Semiconductor. It uses...