This 3-digit digital gauge was found in the July 1900 issue of Radio Electronics magazine. The circuit is based on the CA3161 and CA3162 A/D converters of the time.
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...