Timeline for External ADC reading zero while input is zero
Current License: CC BY-SA 3.0
15 events
| when toggle format | what | by | license | comment | |
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| Jun 17, 2020 at 8:21 | history | edited | CommunityBot |
Commonmark migration
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| Jul 1, 2017 at 18:33 | vote | accept | user30878 | ||
| Jun 29, 2017 at 12:54 | history | edited | Mark Smith | CC BY-SA 3.0 |
Added details gleaned from comments.
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| Jun 29, 2017 at 12:51 | answer | added | Mark Smith | timeline score: 1 | |
| Jun 29, 2017 at 12:45 | history | edited | user30878 | CC BY-SA 3.0 |
added 4 characters in body
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| Jun 29, 2017 at 12:44 | comment | added | user30878 | Not any else component! This is it electronics-tutorials.ws/opamp/opamp17.gif | |
| Jun 29, 2017 at 12:43 | comment | added | Mark Smith | Any input biasing? Please add a diagram. | |
| Jun 29, 2017 at 12:40 | comment | added | user30878 | Simple op-amp configuration, non-inverting and unity gain mode (voltage follower). | |
| Jun 29, 2017 at 12:39 | comment | added | Mark Smith | OK, then your problem is at the input to the op-amp. Please add a circuit diagram, including what's connected to the input of the op-amp, and then we can answer without guessing. | |
| Jun 29, 2017 at 12:31 | comment | added | user30878 | Op-amp's output is always connected to ADC input but nothing connected to op-amp's input in my case. By fluctuate I mean randomly floating values. | |
| Jun 29, 2017 at 12:28 | comment | added | Mark Smith | That's an interesting point - I assumed the poster was asking about when nothing was connected. @user30878, could you clarify please? Are you asking how to get 0-readings when nothing is connected to the ADC, or are you saying you get fluctuating readings when you have the opamp connected but nothing connected to the op-amp inputs? (Or something else?) | |
| Jun 29, 2017 at 9:53 | comment | added | Majenko | You get the output impedance and the 10k in parallel, so if the output impedance is considerably lower than 10k then the 10k will have virtually no effect on the signal. | |
| Jun 29, 2017 at 7:37 | comment | added | user30878 | Ok. But what will going on when input is connected? I'm asking because I want to understand before trying. | |
| Jun 29, 2017 at 7:35 | comment | added | user30878 | Signal is op-amp buffered pH sensor signal so its impedance is near by zero I think. | |
| Jun 29, 2017 at 7:26 | history | asked | user30878 | CC BY-SA 3.0 |
