This circuit is from a 1968 Texas Instruments documentation. The components are from the time and the sensor photodiode is difficult to obtain today. The circuit has a response from 10 Hz to 20 kHz.
Found in English documentation, this circuit uses a thermistor as a sensor. The trigger point is...
The circuit is from the 1990 Motorola Linear Databook. Equivalent operations can be used and what...
We find this circuit in an old documentation, but it can be made using modern transistors. The circuit...