Found in 1967 Raytheon documentation, this circuit uses a company coupler consisting of a lamp and an LDR. The transistor is according to the load current.
This amplifier for sound equipment was found in the Philips Databook of 1990. The circuit can be...
The circuit in the figure causes an incandescent lamp to flash at a speed determined by the...
Using an LDR, this Philips circuit directly activates a relay when light strikes the sensor. The...