This circuit was obtained from an 80's Electronic Engineering. The circuit detects ice formation by triggering a warning light. The operational amplifier is of the time.
This complex circuit with many digital components measures inductances in 6 ranges ranging from 100...
This circuit was found in old publication from 1958. The circuit uses germanium transistor, common in...
Some old analog multimeters use a 22.5 V battery for high resistance measures. These batteries can no...