We found this circuit in a Philips documentation from 1965. The circuit uses a common LDR sensor and the transistors are general purpose types. TR2 can be a BD135.
This circuit monitors the output level of an amplifier. The circuit is set to R4 and can be...
This clipper or limiter circuit limits the amplitude of AM or FM audio signals. The diodes are...
This circuit controls the passage of the signal from an input to an output using a DC signal from a...