Timeline for Linear regulator doesn't always operate correctly depending on order in which power pins are connected
Current License: CC BY-SA 4.0
10 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 17 at 14:46 | vote | accept | Jordan M | ||
| May 17 at 2:34 | comment | added | Jordan M | @AnalogKid Q4 and Q6 are for reverse current protection | |
| May 17 at 1:57 | comment | added | AnalogKid | What is the design intent for Q4 and Q6? | |
| May 17 at 1:37 | answer | added | Spehro 'speff' Pefhany | timeline score: 2 | |
| May 17 at 1:11 | comment | added | Jordan M | @JonathanS. That would be a great idea. Unfortunately this interface is a de-facto standard for Eurorack synthesizer modules, so I can't make modifications to it without sacrificing compatibility. I think the answer may probably be to always ensure the power is off before connecting anything, unless there might be a way to block the both the power rails before ground is connected (I would like to protect the end product against abuse if possible) | |
| May 17 at 1:01 | comment | added | Jonathan S. | In general, hotplugging an IDC connector like this one is an invitation for trouble - imagine what'll happen when -12V and +5V come up first (before ground). Your +5V could become +10V for a moment (relative to the floating ground) and fry everything connected to it. You need at least some way to ensure that ground always connects first. | |
| May 17 at 0:53 | comment | added | Jordan M | @JonathanS. Thanks, that's an interesting hypothesis. The load is an analog synthesizer oscillator circuit composed of many TL074 op amp chips. I'm not sure if they are behaving strangely when the -10.5V rail comes online before the +10.5V rail does. The overall schematic is large so I might see if I can reproduce the issue with a minimal setup first. | |
| May 17 at 0:44 | comment | added | Jonathan S. | This is likely not a problem with the regulators themselves, but rather with the load connected to them. It draws too much current to allow the positive regulator to start up properly when the negative one comes up first. So... What's the load? How's it connected to the power rails? | |
| S May 17 at 0:37 | review | First questions | |||
| May 17 at 4:44 | |||||
| S May 17 at 0:37 | history | asked | Jordan M | CC BY-SA 4.0 |