The circuit is from 1968, but we can use a modern one like the 741. The symmetrical power supply voltage (two batteries or source) can be from 9 to 12 V.
The figure shows how to control the blinking of a 5 V blinking LED with an LDR. The LED only...
Suggested by Maxim in documentation from the 90s, this circuit has its response curve given next to...
This circuit is from a 1965 General Electric publication. It uses a thermistor to fire a reed...