This circuit was found in a 90s Popular Electronics. It is possible to analyze the voltages of an automotive battery. The integrated voltage comparator circuit admits equivalent.
This circuit transmits the sound signals from a television or amplifier to an FM receiver at up to...
This is one of the first games that came out in the 70s. This one is from a Radio Electronics...
We found this circuit in an old American documentation. The operational amplifier is not common...