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.
This circuit can use a pendulum sensor. We found this configuration in a 1994 publication. The...
This circuit is from a 1964 Electronic Design. The sensor is an LDR and the transistors are...
This circuit works both as a preamplifier and activates a relay when speaking in front of the...