Mapper

[ngreen11]

I want to make a tester of sorts. It would be for identifying cable jacks in the house. Basically I will put a "transmitter" on the cable jack then at the meeting place in the basement or wherever I will connect a "receiver" on each cable, one at a time of course. The "receiver" will light a different led for each "transmitter". I will then be able to tell which cable goes to which room. I suspect I will be using some type of ic but I don't know much about them. I would like to have at least four "transmitters" in the set but maybe more. When I use the term "transmitter" I know that it won't actually be transmitting anything. I'm thinking of just having a resistor in the "transmitter" and having the "receiver" then determine which resistor is which and light the according led. Any help at all will be greatly appreciated. Yes I'm knew to circuit building but have a strong desire to make things myself. Thanks again everyone!

 

[Arouse1973]

As you say put a known resistor value, different of course on each jack in each room. Make a note of the values and then go to the basement with a multi meter and measure the resistance of each end of the receivers. This will tell you which room the jack socket is in.
Adam

 

[ngreen11]

Yes I know that will work but I am a cable technician and do this a hundred times a day. I need something faster and more efficient plus I want to make it lol.

 

[Arouse1973]

Oh sorry you didn't say it was a repetitive task. let me have a think. Oh how many would you need?

Adam

 

[ngreen11]

Thanks! Any help would be great!

 

[Arouse1973]

How may connection per jack do you have?

 

[ngreen11]

At least four. Maybe more if it's easy to add more.

 

[ngreen11]

One transmitter per jack. At least four maybe more if it's easy enough to add them to the project.

 

[ngreen11]

Just to clear everything up because it got kind of messy for a bit. I will use one transmitter per jack and I would like to have at least four transmitters. Maybe more if it's easy enough to add them to the project.

 

[(*steve*)]

4 different tones based on DTMF frequencies and a DTMF decoder with a LED illuminated for each frequency?

So each "transmitter" is a simple oscillator injecting an audible tone (or a pair of tones), this could be very low powered, something based on a CMOS oscillator and sending a burst every couple of seconds to preserve battery life.

Unfortunately DTMF decoder chips now seem to be difficult to get hold of. The only one I found had a bitwise serial output -- parallel is way easier to handle

 

[ngreen11]

Thanks for the reply but I don't really need it to make tones, plus.....I have no idea what you just said lol. I'm just a beginner and im certain that this can be done somewhat simpler than that. Thanks anyway. Anything super easy lol?

 

[(*steve*)]

get 4 radios, plug the earphone jack into the cable under test. Listen to them at the other end. Once you figure out the station you'll know which cable it is.

Alternatively, follow the resistor advice.

Have a plugs with 150k, 22k, 3k3, and 410ohm resistances (the last one may need more than 1 resistor to get that value).

Get a multimeter and measure the resistance. If it starts with a 1 it's plug 1, 2, plug 2, 3, plug 3, 4, plug 4.

The resistances are also very different so you can be sure that faulty connections are unlikely to lead to an incorrect result (you would need to examine the actual resistance to do that)

You need to be aware that "really simple to use" does not mead "really simple to make".

My suggestion was more directed at others who may be reading this thread and who may be able to come up with an available chip or device.

 

[ngreen11]

Your idea with the resistors is what I had said earlier was what I thought I needed to do but isn't there a circuit or ic that will turn on an led instead of using a multimeter? I check about 50 to 100 of these a day.

 

[brevor]

I have been working on something like this to sort wires in a bundle. I havn't finished building it yet, it uses different resistors that connect to the remote wire ends. The readout device uses a PIC 16F676 that reads the resistor value through the ADC and shows the wire number on a 7 segment readout. This would probably work for this application too.

 

[ngreen11]

Can you send me a parts list and a schematic? That is an excellent starting point if not the entire project!

 

[Arouse1973]

Your idea with the resistors is what I had said earlier was what I thought I needed to do but isn't there a circuit or ic that will turn on an led instead of using a multimeter? I check about 50 to 100 of these a day.

@Steve, you beat me to it!

Two trains of thought are tone decoding using the NE567. And the only other thing I can think of is a several window comparators measuring the different voltages from the plugs which would form one half of the potential divider.

Otherwise employ a 16 year old. He'll stand there and do this all day for a few quid.

Adam

 

[brevor]

Can you send me a parts list and a schematic? That is an excellent starting point if not the entire project!

Sure, Like I said it's not complete yet. Please send me a private message with your e-mail and I will send you the details.

 

[BobK]

You would not even need window comparators. You could use a single comparator for each voltage. The number of LEDs that light would tell you which resitor you were looking at. A quad comparator, reisistor and 4 LEDs with resistors would do the trick.

Bob

 

[Arouse1973]

You would not even need window comparators. You could use a single comparator for each voltage. The number of LEDs that light would tell you which resitor you were looking at. A quad comparator, reisistor and 4 LEDs with resistors would do the trick.

Bob

Can you draw a circuit then Bob please.
Thanks
Adam

 

[Arouse1973]

This will work with window comparator.

R6 is your connection from your jack resistor at the other end of the cable.

Unit 1 R2 100K R6 1K
Unit 2 R2 82K R6 820R
Unit 3 R2 62K R6 620R
Unit 4 R2 43K R6 430R

You will need one circuit for each cable.
Just an Idea.
Thanks
Adam