Timeline for Make a switchable steady 5 V output circuit
Current License: CC BY-SA 4.0
15 events
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| Feb 21, 2023 at 18:56 | comment | added | vir | Not a knock on you but this is very much an XY problem. The Arduino has an AREF pin that is specifically designed to deal with this situation. Tie the positive supply voltage of your dividers to AREF and the internal ADC will use that as the "top" of the conversion. Also, it's likely that the internal ADC has 10 bits of resolution which means that each "step" is 4.9 mV with a 5 V full scale. | |
| Feb 21, 2023 at 11:31 | vote | accept | R Doyle | ||
| Feb 21, 2023 at 9:54 | comment | added | R Doyle | @vir It is going to supply 4 voltage-dividing circuits with thermistors for temperature measurement. So the more accurate the input voltage is the more accurate my measured voltages will be. Current shouldn't be an issue I don't think. Stable enough to temperature, given the goal. I'd say the response could be long enough I will only be taking measurements every few minutes but the whole point is to turn the thermistor circuit on and off with the Arduino so the thermistors don't self-heat. So maybe then the transient response needs to be short? | |
| Feb 20, 2023 at 17:46 | comment | added | vir | This sounds like an XY problem to me. What are you planning on doing with this 5 +/- 0.001 V power supply? How much current does it need to supply? Does it need to be stable over temperature changes? What transient response do you need? | |
| Feb 20, 2023 at 17:45 | comment | added | R Doyle | Ok thank you for your help | |
| Feb 20, 2023 at 17:41 | comment | added | winny | Close to 0 % chance on +-1 mV happening. Product recommendations are off-topic here but here are 1751 available 5 V regulators with enable pin to limit your search/point you in the right direction: digikey.com/en/products/filter/power-management-pmic/… | |
| Feb 20, 2023 at 17:34 | comment | added | ocrdu | 1 mV accuracy is more precise than any integrated linear regulator I've ever seen, but who knows. If you go looking for 7805 alternatives anyway, you may as well select one with a shutdown pin. | |
| Feb 20, 2023 at 17:24 | comment | added | R Doyle | @winny Probably on the order of 1mV. Is there a better option than an LM7085? No, I hadn't I didn't know they existed. Would have any suggestions? | |
| Feb 20, 2023 at 17:20 | comment | added | winny | Welcome! "very accurate" != 7805. How much accuracy do you need in numeric terms? Have you considered a linear regulator with an enable pin to simplify things? | |
| Feb 20, 2023 at 17:18 | history | edited | R Doyle | CC BY-SA 4.0 |
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| Feb 20, 2023 at 17:16 | history | edited | R Doyle | CC BY-SA 4.0 |
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| Feb 20, 2023 at 17:16 | history | edited | ocrdu | CC BY-SA 4.0 |
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| Feb 20, 2023 at 16:28 | answer | added | Andy aka | timeline score: 2 | |
| S Feb 20, 2023 at 16:20 | review | First questions | |||
| Feb 20, 2023 at 17:22 | |||||
| S Feb 20, 2023 at 16:20 | history | asked | R Doyle | CC BY-SA 4.0 |