Originally Posted by DonH50
If the power supply in a component does not have enough charge storage (capacitance) to keep it working during a brief outage until an off-line UPS switches over, and/or not enough line isolation to reject noise spikes and these short glitches before the UPS takes over, then you can get flickers as you see. And may hear pops in your speakers, see lights flicker, etc. If the voltage drops out long enough that a component like your TV has to restart then you may see a longer interruption until the picture comes back. The power was switched quickly, but the TV sensed it went away and started shutting down, then had to start up again. Manufacturers will use the cheapest power supply they can get away with so this may not be uncommon.
That was fantastic!!
I have been searching around, talking to people, and jumping from forum to forum trying to make sense of what was happening and link my observations to see if the "theory makes sense". One of the issues which i didn't mention - My AVR and PC both behaved fine. No pops from speakers or restarts of either, nor any peculiar weird behavior by either the PC or the AVR. Although being a receiver, it has a fairly decent PSU - Marantz SR7005. I had the feeling it has to be my PSU and the capacitance used, but wasn't sure. Hence went fishing and I ended up getting some theory that usually left something unexplained, or the easy answer being "just use an online UPS", or even build a generator in the basement, but never a complete reasoning as to why I might be facing the issues. So if one cant explain my issues and link it with observations, then the theory is flawed.
Thanks for that Don. Makes sense!! Explains most of my problems.
I have two more questions. Hope you can help me with that.
1. Will daisy chaining UPS cause any issues?
I searched around with no clear answers or reasons. Daisy chaining meaning - The first UPS is a full house unit which powers everything except refrigerators, iron machine and motors. The second UPS (Line Inverter) is for my sensitive electronic equipment like display, receiver and PC. The second unit is plugged into the wall, which is supplied with power coming through the first UPS. I might have to do some crazy external wiring if I have to skip the first UPS and connect the second UPS directly to mains power.
2. I am trying to understand why this below issue is occurring.
One other problem that I face is, when the first UPS goes to battery, at times the second unit jumps from its battery to mains and back regularly. When the second unit comes back from battery to its mains, the display flickers.
(a). I think, when second UPS goes back to its mains, there is an instantaneous higher current draw seen at the first UPS which is still on its battery. The second UPS, just jumped from battery to mains, but its mains the first UPS being on a battery - could not supply the instantaneous higher current draw (maybe not enough juice left in the battery). But again, this instantaneous higher current draw is not one similar to one which is seen when devices are switched on, these devices are already on and drawing more or less constant current.
(b). Is my solution to this, connecting the second UPS directly to the main power instead going through the home UPS unit. This way when the UPS goes back to mains, the mains has the capacity to feed the instantaneous current draw, which my battery driven UPS may not be able to. Am I right here?
With daisy chaining, I might be fine if there is an efficiency issue with daisy chaining. But safety, well...