Published by Philips in 1965 documentation, the sensor for this circuit is a common LDR. The transistors are general-purpose types from the time, only TR3 is a power type according to the load.
This circuit was found in the December 1992 issue of Radio Electronics magazine. The current is a...
The basis of this circuit is the 723 integrated circuit, not very common today. We obtained this...
DC motors of 6 to 12 volts and currents of up to 2 amps can be controlled with this shield...