Timeline for Voltage leak when muxing Li-ion cells for voltage measurements?
Current License: CC BY-SA 4.0
12 events
| when toggle format | what | by | license | comment | |
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| May 28, 2023 at 18:03 | comment | added | Mr.Thinkage | @KevinWhite, I agree, but I can't imagine where the resistance is coming from, there is a jumper wire connecting them. I measure 5ohms between any two points on my breadboard gnd rail. and 30ohms (With the power disconnected) between MCU gnd and breadboard gnd. I have a higher quality breadboard that I could swap this out for to see if that helps. | |
| May 28, 2023 at 17:44 | comment | added | Kevin White | @evildemonic - in normal operation at least one channel should be active so the impedance of the meter shouldn't matter. | |
| May 28, 2023 at 17:43 | comment | added | Kevin White | @Mr.Thinkage - 80 ohms ground continuity sounds rather high. I would hope it would measure less than 1 ohm. | |
| May 28, 2023 at 17:26 | comment | added | Mr.Thinkage | @evildemonic I had a 10kohm pull down resistor, the problem persists with a 3.3k | |
| May 28, 2023 at 17:23 | comment | added | Mr.Thinkage | @Neil_UK, yes they share a ground, when I measure continuity it shows 80ohms between the ground of the mux and the ground of the MCU. | |
| May 28, 2023 at 17:21 | comment | added | Mr.Thinkage | @KevinWhite mux has 5v on vcc pin. Measured logic is max 1v as LOW and min 3.9 HIGH, within the 30% specified on the datasheet. | |
| May 27, 2023 at 0:15 | comment | added | user319836 | Sounds like the ground pin on the multiplexer is not connected properly. | |
| May 26, 2023 at 21:38 | comment | added | evildemonic | I wonder if the leakage current is getting you because the voltmeter is very high impedance. If you apply a 1 mA load to the output (pin 1, resistor to ground) does the problem go away? | |
| May 26, 2023 at 21:33 | comment | added | Neil_UK | does the MCU share the same ground as the mux? | |
| May 26, 2023 at 21:27 | comment | added | Kevin White | That shouldn't happen. What logic voltages are bing supplied? Does the multiplexer have power? | |
| S May 26, 2023 at 20:36 | review | First questions | |||
| May 26, 2023 at 21:46 | |||||
| S May 26, 2023 at 20:36 | history | asked | Mr.Thinkage | CC BY-SA 4.0 |