Like all its counter Parts, this network wiring tester comprises two elements, a transmitter unit, powered and fitted at the network start point, and a receiver unit, passive, which can be moved around from socket to socket. Each of these units carries eight LEDS, identically labelled 1 to 8. By operating a push-button in manual mode, or using a clock in automatic, the eight LEDs light up in sequence on the transmitter unit and obviously they should do the same on the receiver unit. In this way, just by watching the LED lighting cycle on the receiver unit, you can immediately spot any crossed wires, as well as any open circuits (the relevant LED never lights up) or shorts (two or more LEDs light at the same time). Circuit diagram : Network Wiring Tester Circuit Diagram The transmitter unit circuit is simple' The Schmitt-input NAND gate lCl.A is wired as a multi-vibrator, whose speed can be adjusted using Pl, while lCl.B is wired as a simple debounce circuit for button 52, used...