This simple circuit, found in American documentation, uses only one relay that locks when any of the sensors is activated. To reset, simply turn off the power for a moment.
This circuit can operate with 5 uV to 1 mV input signals from low impedance sources such as...
This very simple circuit with neon lamps indicates who pressed the button first, lighting the...
This circuit was originally designed for the practice of Morse code, something common in 1966, the year...