Good day folks. Some of you may know that this place where I work at gets its hands on all sorts of crap, from your usual stuff like TVs and PCs to fairly niche stuff like audio mixers and to downright junk like VCRs and CD players.
The device I currently have on hand falls in the second category, niche stuff, which is a set of digital scales which you'd find in a small supermarket. It's not a cash register, it just weighs stuff and displays it. It turns on alright but the problem is the readout never stabilizes: it fluctuates up/down by roughly 5 grams and it seems it tends to keep going up rather than down. I snapped some pics of the interior...nothing special: a load cell with some metal stuff attached to it for supporting the top plate and a simple board. I haven't worked with load cells before so I don't know what I should be looking for exactly and what causes unstable readings in them. I see 4 wires going to it: two of them are obvious (VCC and GND), but the other two, from what I've read are the "signal" wires which is not even a communication protocol or anything - just a set of resistors (Wheatstone bridge ?) which change value. Is it the load cell itself that is likely to be faulty in such scenario (by having something over its maximum limit placed on it for instance) or is it more likely to be an electronic issue like an op-amp ? What do you guys think ?
Two burnt resistors there, I know, but those are likely part of the battery circuit which experienced a bad battery and caused them to overheat, but I don't think they're part of the issue here...
The device I currently have on hand falls in the second category, niche stuff, which is a set of digital scales which you'd find in a small supermarket. It's not a cash register, it just weighs stuff and displays it. It turns on alright but the problem is the readout never stabilizes: it fluctuates up/down by roughly 5 grams and it seems it tends to keep going up rather than down. I snapped some pics of the interior...nothing special: a load cell with some metal stuff attached to it for supporting the top plate and a simple board. I haven't worked with load cells before so I don't know what I should be looking for exactly and what causes unstable readings in them. I see 4 wires going to it: two of them are obvious (VCC and GND), but the other two, from what I've read are the "signal" wires which is not even a communication protocol or anything - just a set of resistors (Wheatstone bridge ?) which change value. Is it the load cell itself that is likely to be faulty in such scenario (by having something over its maximum limit placed on it for instance) or is it more likely to be an electronic issue like an op-amp ? What do you guys think ?
Two burnt resistors there, I know, but those are likely part of the battery circuit which experienced a bad battery and caused them to overheat, but I don't think they're part of the issue here...
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