Timeline for High neutral-to-ground voltage of switching mode power supplies
Current License: CC BY-SA 3.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jan 28, 2017 at 22:33 | vote | accept | BrianB | ||
| Jan 28, 2017 at 22:33 | comment | added | BrianB | Now I have a problem that the V- input is sitting at 8V while the V+ input is 0 (both relative to ground), but I suspect I damaged the opamp through my prior poor power wiring or through ESD, so that's a new and different issue. Thank you, Peter. | |
| Jan 28, 2017 at 22:30 | comment | added | BrianB | To follow up: I took Peter's advice, but being cautious I decided to use a spare 2.7k resistor between the neutrals and ground. After doing so, the neutrals were very nicely behaved and the voltage across the resistor was negligible, which validated Peter's point that the current available was tiny. In the final circuit I'll probably use wall neutral instead of ground to ensure all current is returning through neutral, and avoid problems with GFCIs if present. | |
| Jan 23, 2017 at 3:04 | comment | added | Peter Bennett | The voltages you are seeing are due to AC filter capacitors, and capacitive coupling between the input and output of the power supplies - there will be very little current available from these sources, so you can safely connect the supplies to an earth ground, or other grounded devices. | |
| Jan 22, 2017 at 20:58 | comment | added | BrianB | Would that stop the neutral from reaching 65 V or does it just ensure they are using the same neutral? I forgot to also mention that the output neutral needs to be safe, see edit. Can I tie both neutrals to ground through some impedance to ensure the output is safe? | |
| Jan 22, 2017 at 18:32 | history | answered | Peter Bennett | CC BY-SA 3.0 |