A friend is trying to identify a device on a circuit board. It is identified as a resistor (R34) and looks like a resistor, but only has one band. If that band was black I;d say it was a "zero ohm_ reistor
- aka a "jumper" but this is a single blue band at the one end. Looks like about a 1/2 watt.
There are actually 2 of them on the board. It is the probe board from an Amprobe ACD14 Plus which has gone out of calibration. No schematics are available -and apparently no parts either.
sci.electronics.repair
As to parts, you can grind up walnut shells and mix it with some copper dust and press it into the shape of a resistor. I have no idea what its value will turn out to be, but it's a good activity for a rainy weekend.
Any signs from the traces on the board that it's in series with the current leads? It may be some proprietary high precision, low ohm resistance to generate a voltage to measure the current?
- google search only
- is it related to a zener diode - see link - and poorly labeled ? .. click on the thumbnail photo to enlarge
John T.
Most definitrely NOT a zener, Not at akk simuikar to the one shown.
Mabee it;s green.
See it at
The band looks green to me. Off hand I would say it is a 5 ohm resistor and looks like it could be some sort of wire wound. It may even be a
1/2 ohm resistor. There seems to be 2 of them. Has he tried measuring them ?
They are also right at the input terminal of that current measuring probe, which is the question I raised earlier. Clare won't see it, he ignores me, so his loss. I suggested that they might be special precision resistors that convert the current to voltage for measurement. Now that we have a pic, I agree they look like they could be wirewound. Another question, what's the point here? Just curiousity? Did he measure the resistance? I'd expect it's very low.
Another thing, there is a gold band resistor in between. I wonder if those two are low ohm wirewound, maybe all three are in parallel and the gold band one is hand selected at assembly to adjust and set the exact resistance for the combo of all three?
Isn't there any schematic that can be looked at????
"No schematics are available -and apparently no parts either."
Not that I have found It is an Amprobe ACD14plus. If you can find a schematic, I'd be gratefull (and so would my friend Kevin)
use an ohmmeter to compare them
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