Quote: Originally Posted by Lady Fitzgerald
I looked up the specs on this and the mfgr. says it has a simulated sine wave. What the heck is that? Pure sine wave? Modified (stepped) sinewave?
Now from what I can gather from this article (below) and my own experience of building rectifying circuits and inverting circuits when I used to dabble in building stereos, electroplating systems, and any electronically controlled system it is the sine wave that is produced by the device in an outage and produces the voltage at a waveform that "simulates the incoming mains voltage.
You will see that the sine wave produced is very irregular in that it is not a smooth and continuous waveform that you get from the mains supply, in fact it looks like it would not work at all because the pics in the article depict what looks like a series of dashes. But again in those circuits the frequency could be many more "cycles" than the incoming mains would show. The circuitry puts that extremely fast frequency back into the frequency required by your devices.
It also mentions that this type of waveform is used in the cheaper UPS's - the one I got has a 510 watt capacity that I think I saw somewhere with all my devices hooked up - that would be two desktops, one laptop, three sound systems, a modem a modem switch, the telephone(it is a landline with the supply required for speakerphone) and maybe two desklights (which are heavy users I've since found so are only on when I need them) I would six minutes of time to shut down every machine.
Remember the device in an outage is just "converting" the stable 12v (or whatever voltage the manufacturer sets for the battery) back into the alternating waveform voltage of what the incoming voltage (and waveform say in my case 50Hz) which is then used for the purpose of shutting down the machines - whatever you have on and running at the time.
This is I am assuming is why they say not to hook up large current drawers like printers. photocopiers etc.
I can't tell you how "simulated" type of wave form my UPS produces beacause I do not have an oscilloscope any more but as this device cost me $170 I am just guessing it is a fairly good quality one, and may show a better. It as it is quite a bit heavier one than the Belkins and has a digital readout on the device which is where I think I saw the time I have to shut down the machines and looks to be a much better quality build than those Belkins too. EXTREME Overclocking - Belkin F6C1500TWRK 1500VA Battery Backup UPS Review - Page: 6 - Tweaking PC Hardware To The Max
There are other references to this question via Google but I though this was a good one because of the oscilloscope pictures / readouts. There are some that mention "interference in the lower end ones but I run for my own reasons surge boards beyond the UPS that will take care of the mains clutter and I guess there will be many more far better qualified than myself who will not like my system of doing things but I personally cannot see any difference in doing this as the electricity flows through both and unless someone can tell me what the danger is I shall carry on doing that.
To me it is like running water through a pipe with a filter then through another fitter and so on with no loss of pressure.
Anyway I suppose the bottom line is that it is better than nothing?