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.
The circuit shown in figure 1 is suggested by Maxim (www.maxim-ic.com) and makes use of the...
This high impedance circuit uses a 12 V lamp to test voltages in a car. We found it in a Popular...
This circuit was found in an Electronic Design. It makes use of a relaxation oscillator to trigger...