This converter was found in the June 1991 issue of Radio Electronics magazine. The circuit uses common circuits at the time and its operating range can be changed.
Found in American documentation from the 90s, this circuit can measure frequencies on a linear...
This circuit was found in a 1980s US publication. It indicates when the phone is off-hook by...
This circuit was found in a Philips documentation from 1966. The circuit provides 1 mW with a...