UPS Madness

There are plug-in replacements that replace the PC PS and will run directly off the battery. So no swap over time, but you pay an extra 10% in power to top up the battery(deep discharge lead acid)

Middle flashy one.

It does actually make sense if you consider you need to deal with one generic black box and interface it with many different types of other black boxes, and expect all that mess to actually work.

Back in the early days, you could get a UPS in the shape of an internal card, which fed power back into the system via the slots and existing cables. But you were dealing with one base, and it was consistent.

Today, when you're dealing with an assortment of various power rails, pretty much the only consistent single power source you have is that

240vac.

Your argument is certainly stronger when you're talking about laptops in cars for instance. Why go from 12v, to 240vac, then 240ac down to

9-19vdc, when you could do that with one step with a DC/DC converter. Or in some cases, I've read that some who have 12v input laptops plug the car's electrical system directly into it. Too risky IMO, but people insist on doing it...

Converts into many voltages typically.

Also other things (monitors etc) are usually run from the UPS. In a couple of cases I have seen a small CFL being run from one of the sockets to give a bit of light in the room if the power fails at night.

I also leave the ADSL router on the UPS, this way you can use the VOIP phone, and connect the laptop if there is something urgent you are doing on the net that just cant wait.

This is the key - its universal and can run just about anything you plug into it. (within its specified limits).

Finally, UPS only runs when the mains power fails, and usually left on just long enough to save work and safely shut down. This isnt likely to be very often to waste much power due to the inefficiency of the setup.

I think it is understandable with a fairly specialised product like a UPS. However, it seems _really_ crazy when the same principle is applied to entire households. The increasingly popular use of solar panels to provide power to a home full of low voltage lighting and electronics cries out for a standard low voltage DC power rail.

When you have a bunch of those awful halogen downlights running at 12 v

4 amps each, you quickly realise its much more efficient to run 240 volt to each point than install a 12 volt bus. And how much of that electronics runs at 3.3,5,6,9,12 or 15 volts ? Getting a standard for all that diverse stuff seems unlikely.

--
Regards,

Adrian Jansen           adrianjansen at internode dot on dot net
Note reply address is invalid, convert address above to machine form.

I will stick with the common lead acid battery voltages thank you. Good enough standard for me. However, as pointed out, that is all very fine when everything is at the same point. When it comes to transmitting it even a hundred metre, cabling losses start to make higher voltages preferred. hence it is easier to go with the commonly available 240V gear.

Cabling losses, as well as the possible need for isolation of power supplies for certain devices would be issues

There is also the greater fire risk (risk of arcing being maintained with DC unlike AC) with DC supplies. (QH transformers are 12v AC and therefore arent a problem.)

Making much more efficient switchmode supplies might be a better idea.

My F&P washing machine was emitting a noise during its emptying cycle that anyone here would recognise as meaning that the pump bearings were worn out.

It turns out that the pump can be replaced without any tools whatsoever: Unplug from the mains, disconnect the pipes from the taps, pull the waste pipe out of sink and tip the machine on its side (access to the innards is from underneath). Pull the two power lead spades off the motor, press a plastic tab to let the motor/pump rotate in its mounting, and it can be pulled out. Installing the new one is just the reverse.

I wish all repairs were that simple. Nice one F&P.

Sylvia.

Sorry, I didn't intend to for that to be a reply.

Sylvia.

I discovered that myself a few months back on a friends machine. Fortunately there wasnt anything wrong with the pumb, except for a stocking wrapped around the impeller. Removed this, replaced the pump & it all worked fine.

:Is it just me or does it seem crazy to everyone that a UPS takes, say, :12V from a battery, converts it to 240V AC through some fairly complex :electronics, just to have another set of electronics convert it back to :12V and below. Thoughts? : :Cheers, :Michael

Not madness at all...

How else do you think you can source 240Vac power when the mains supply normally used by the PC is not there? I suppose you could replace the UPS with a petrol genset but other than that what options do you have?