Cable tracker
Cable tracker is a device that will help you in finding cables that are placed in thick walls up to 15 cm, or there is a possibility to use them in cases when you have to find the right cable in a bunch of cables. It consists of two parts: transmitter and receiver. In cases when you are using it, the transmitter is connected at the start point of the cable which sends a recognizning signal through the cable, which you have to follow with the receiver. It is a simple project but very handy, because it can save you a lot of trouble during cable tracking.
The receiver
The schematics of the receiver is presented below. It is a very simple schematics, made of the following parts:
- Antenna is made of isolated wire with length of 10 cm. This wire must be protected, so it would be nice to place one plastic pipe of the same length or just 1 cm more, and insert the antenna in it.
- High pass filters (C1, R2)
- Amplifiers (IC1) output (T1)
- Speakers with high impedance of 220R, which you can find in phone handsets
Parts list for the receiver
Antenna – 10 centimeters of wire
Battery – 9 V
Switch
C1 – 39pF
IC1 – CA3031T1
LED1 – 3mm, green
P1 – 50k
R1, R2 – 1M
R3, R4 – 1k
T1 – BC547
Potentiometer P1 is placed for setting the amplifying of the device. The “ground” is connected with the metal part of the switch.
The transmitter
Below this section, I have presented the schematics of the transmitter. I have used “timer 555”, but is used two of them, and that is why the hosuing is listed as 556. The other timer is used for modulation of the signal, which is produced by the first timer. The output frequency varies between 2100 Hz and 2200 Hz. The signal is easily recognized. The output is actually made from one resistor R6 and short piece of wire that acts as antenna, while the other end is connected on RJ11 and RJ45 slots on the box.
Parts for the transmitter
Battery - 9 V
C1, C2 - 100nF
C3 – 10 uF for 63 V
IC1 – NE556N
LED1 – 3 mm, green
R1 – 10k
R2 – 100k
R3 – 68k
R4, R5 – 2.2k
R6 – 100R
R7 – 1k
Switch
Important: This device should be used while there is no voltage applied on the cable.
