This continuity test was found in a 90s Electronic Engineering. Transistors are types of general use of the time with equivalents such as BC548 and BC558.
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...