This circuit was found in a Hands On Electronics from the 80's. The circuit emits an audible alert when dawn and the sensor receives solar illumination.
This circuit makes use of a special LM195 power transistor not very easy to obtain. The circuit is from...
Found in documentation from the 90s, this circuit can employ other comparators in the series such as...
Suggested by Philips in a 1970 publication, this circuit uses components from that time. No...