Timeline for Op-amp subtractor - why is the output wrong?
Current License: CC BY-SA 4.0
7 events
| when toggle format | what | by | license | comment | |
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| Oct 3, 2021 at 17:32 | comment | added | Andy aka | @Marla those old dual op-amps can probably stand that situation!! | |
| Oct 3, 2021 at 17:01 | comment | added | Marla | Just for fun Andy : no one mentioned the other half op-amp floating inputs. | |
| Oct 3, 2021 at 14:49 | comment | added | Andy aka | @PrathikPrashanth there are dedicated chips that will do this based around an op-amp whose input range includes the positive supply rail. They output a current that is a small ratio value of the measured current and, a ground connected resistor converts that current into a ground referenced positive voltage. Available from TI and ADI. Off the top of my head I can't think of part numbers but, you can build it from an op-amp and a MOSFET. OK, LT6105 springs to mind. And, I think the MAX4172 also works. | |
| Oct 3, 2021 at 14:25 | vote | accept | Prathik Prashanth | ||
| Oct 3, 2021 at 13:58 | comment | added | Prathik Prashanth | So will using something like 0.1% resistors fix the problem, or should I look for other options (like a hall effect sensor)? | |
| Oct 3, 2021 at 13:05 | history | edited | Andy aka | CC BY-SA 4.0 |
added 54 characters in body
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| Oct 3, 2021 at 12:58 | history | answered | Andy aka | CC BY-SA 4.0 |