Novel network cable automatic detection device

The working principle of the circuit of this network automatic tester is shown in the figure below. Use 555 circuit to make a symmetrical square wave oscillator with frequency f=1Hz, connect IC1 pin ③ to IC2 CP terminal, and each output pulse signal is based on IC2: Q1~Q8, IC3:

Q1~Q8 output positive pulses in turn, and C2, R3, IC2, and IC3 provide power-on reset signals.

Note: Make sure to connect the pins of IC2 and IC3 in the same order, otherwise the output indication signal may be irregular. If the wiring is correct according to the diagram, it can be used normally without debugging.

Selection of electronic components: IC1 uses NE555 time base integrated circuit, IC2 and IC3 are CD4017 decimal counting/distribution integrated circuits, and they all use dual straight plastic hard packages. The right figure is a schematic diagram of the pin arrangement of the two integrated circuits. R4~R19 uses RTX-1/8W carbon film resistors with a resistance of 820Ω: Rl, R2, and R3 are 15kΩ, 30kΩ, and lkΩ respectively. The resistance values ​​of R4~R19 are all 1kΩ. VD1~VD2 can use 1N4148 diodes. Cl is an electrolytic capacitor with a withstand voltage of 15V and a capacity of 10uF. C2 is a ceramic capacitor. S is a 1×1 small power switch. E can use a 6F22 9V stacked dry battery to reduce the size of the whole machine.

4 RJ45 plugs of CT1 and CT2 connecting cables are inserted into the female sockets CZ1 and CZ2, or 4 BNC coaxial cable sockets are used. There are no special requirements for other requirements, which shall be subject to the markings in the figure.

How to use: Insert the male crystal plugs CT1 and CT2 into the female sockets CZ1 and C22 at both ends of the network cable to be checked, and then turn on the power of the network automatic tester. At this time, the first group of LEDs LED1~LED8 and the second group of LED1~LED8 flash in sequence, indicating that the network cable is correctly inserted. If a certain LED does not light up, it indicates that the corresponding connection has a cold solder joint. It takes about 8 to 10 seconds to accurately complete the detection of two 8-core network cables.