This circuit is from a 1964 Electronic Design. The sensor is an LDR and the transistors are general-purpose types. The circuit triggers when the light that falls on the sensor is cut off.
With this circuit it is possible to control an operational amplifier so that it switches an input...
This circuit consists of a traditional amplifier version with complementary output using BD series...
This circuit was obtained from a Texas Instruments 1985 document. The circuit is powered by 1.5 V...