This circuit was found in a Popular Electronics from the 90s. The circuit uses an ultrasonic microphone. The indicator is dual with LED and Buzzer.
This old taster circuit, found in 1970s American documentation, is for operatives and comparators of...
November 2016 - Mouser Electronics is supplying the MAX30205 from Maxim, a human body temperature...
This circuit was found in Motorola's 1966 documentation. HEP556-type integrated circuits can be...