This telegraph monitor was found in an American documentation for radio amateurs from the 1970s. The indicator is a common 1 mA full-scale milliammeter.
Found in Maxim's documentation from the 90's, this circuit uses a component from the time and has its...
This control of DC motors for currents up to about 200 mA was obtained in an American publication of...
Any TTL inverter can be used in this circuit. We found it in documentation from the 80s, but it...