This circuit was found in American documentation from the 1960s. The operational amplifier is from that time, but the configuration applies to modern equivalents.
This circuit was found in Popular Electronics. Its purpose is to warn the visually impaired when a glass...
This circuit was obtained from a Popular Electronics from January 1967. It has a...
This ultrasonic transmitter was found in a 1974 documentation. The receiver is the CIR11753 or...