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An LM3914 could be made to do this too.
So is this comparator an ic? If so, what number is it and also what schematic would I follow? The first one or the second one? Thank you all that have helped and given advice. I have almost figured this out using an arduino micro but would rather not tie that up when I can make a discreet circuit.
Why not use a small microcontroller, sending a serial character. like a number <1>. The next send a <2> and so on. on the receiving end you need a microcontroller receiving the number and decoding it on a set of LEDs or a display. You could even have an automatic polarity correction, and indicate if the cable is reversed.
If you don't want to use a microcontroller, you can use a much simpler version with logic parts. I could try to draw a logic based tester set for you, but I need some more info.
How many testers do you need working at the same time? (I saw he number 4, but is that practical?)
Do you need to decode each lead in a cable, or is it coded?
Are the cables powerless when tested?
If you don't want to use a microcontroller, you can use a much simpler version with logic parts. I could try to draw a logic based tester set for you, but I need some more info.
How many testers do you need working at the same time? (I saw he number 4, but is that practical?)
Do you need to decode each lead in a cable, or is it coded?
Are the cables powerless when tested?
It will be used for testing coaxial cable. Only one will be used at a time. However I would like four different sensors. I would put one in different locations in the house then where all the cables meet, I would use the tester to find which cable goes where. They must be identifiable. No need for reverse polarity correction. No need to identify separate wires. No power on the line while testing.
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brevor, why don't you post the schematic here. It may be useful to others, and we can check it. I'm interested to see it too. I've started designing a circuit but it has a lot more than eight parts.
Click Go Advanced, then click the paper clip icon. Browse and select the file, click Upload.
Click Go Advanced, then click the paper clip icon. Browse and select the file, click Upload.
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The screen grab would be most useful, however if you wish to (and the files are small enough) you can also zip up the eagle files and attach them.
I would also be interested.
Schematic
Ok I will give this a try, here is the schematic.
Well I cut off the bottom, That bit at the bottom labeled TP2 is the common return to the tester ground. The resistors at the left are the remote unit. For the OP's application these resistors would be seperated.
Each resistor when individually connected between the input and common of the circuit will give a reading from 0 (zero Ohm jumper) to 9 (100K resistor). An open circuit shows a - (dash) character.
It uses a PIC 16F676 microcontroller, If anyone is interested I could post the Hex file here somewhere.
If anyone trys to build this a high brightness common anode display would work best. The segments are individually multiplexed to save power so it's not real bright. This circuit is still a work in progress, I am going to try changing R1 from 100 Ohms to 51 Ohms to try to improve the brightness.
Ok I will give this a try, here is the schematic.
Well I cut off the bottom, That bit at the bottom labeled TP2 is the common return to the tester ground. The resistors at the left are the remote unit. For the OP's application these resistors would be seperated.
Each resistor when individually connected between the input and common of the circuit will give a reading from 0 (zero Ohm jumper) to 9 (100K resistor). An open circuit shows a - (dash) character.
It uses a PIC 16F676 microcontroller, If anyone is interested I could post the Hex file here somewhere.
If anyone trys to build this a high brightness common anode display would work best. The segments are individually multiplexed to save power so it's not real bright. This circuit is still a work in progress, I am going to try changing R1 from 100 Ohms to 51 Ohms to try to improve the brightness.
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That's a good start, but not all of the circuit is visible.
GIF is a better format than BMP for schematics - the cropped GIF in this post is only one tenth of the file size of the BMP.
I see you reduced your screen capture to a monochrome image to make the file smaller. That's a good idea, but if you use GIF format, you may not need to reduce it so drastically - just to 256 or 16 colours, and it may look better as a result.
You can insert the image inline in your post, like I just did. When you've clicked Upload on the Manage Attachments dialog box, the filename will appear in the section marked Current Attachments. Right-click it, and choose Copy Link Location (or similar). Then close the dialog. Then, click the Insert Image tool (below and to the right of the paper clip) and paste the location of the attachment into the entry field.
GIF is a better format than BMP for schematics - the cropped GIF in this post is only one tenth of the file size of the BMP.
I see you reduced your screen capture to a monochrome image to make the file smaller. That's a good idea, but if you use GIF format, you may not need to reduce it so drastically - just to 256 or 16 colours, and it may look better as a result.
You can insert the image inline in your post, like I just did. When you've clicked Upload on the Manage Attachments dialog box, the filename will appear in the section marked Current Attachments. Right-click it, and choose Copy Link Location (or similar). Then close the dialog. Then, click the Insert Image tool (below and to the right of the paper clip) and paste the location of the attachment into the entry field.
Attachments
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