We found this circuit in documentation from the 1980s. It is an input stage for a digital frequency meter. The circuit can operate with signals up to a few tens of megahertz.
We found this circuit in a year 2000 documentation. It must be powered by a voltage of 5 V as it...
This circuit was found in the February 1990 issue of Radio Electronics magazine. The circuit uses...
Voltage comparators, such as those in the LM139/239/339 series, consist of devices that can be...