Using A Ups Power Suppky To A Tv - PeachParts Mercedes-Benz Forum

euronatura · #1 06-10-2008, 07:33 PM

Ok, there are tons of smart people here. So someone may be able to help answer a question.

Problem is, the rainy season just started here in Guatemala and well, I live in the middle of nowhere and the power comes on and off various times per day due to the rain. Power cuts out usually for no more than 20 - 30 minutes and today it cut out 5 times for about 15 minutes each time, since the morning.

I am tired of losing the TV and Direct TV Sat and my internet when the power goes out ( I work from home the majority of the time.) So I want to get one or two of these to hook up to my TV and Direct Box and then another for the internet. Will it work? How long will it last on battery?

My tv is a simple 27 inch thing. The Direct TV box is the normal old Hughes and my internet is an EVDO Modem.

http://www.radioshack.com/product/index.jsp?productId=2262122

Thanks

Iggy

MTI · #2 06-10-2008, 07:52 PM

So long as the current draw of all the devices are within the 390W that the RS UPS batteries provide, it should work.

Angel · #3 06-11-2008, 01:04 AM

I am thinking that you'll need a bit more of a UPS than that model. walk with me as we do some math...

If your 27" tv requires 140W (guess), your computer requires 300W and both the router and cable box require 90W each (all guesses, you may have better numbers...) then you are looking at 620W req'd at any point in time. Already, your UPS choice is too small, look for something bigger than 620W (I think they make 500VA and 750VA models. 1VA (volt-amp) does not equal 1watt, but for this example, they are probably pretty close. Serious EE's will call me out about the capacitive loading of your TV (if its a CRT...), and I'll take that hit, I've forgotten my AC theory.

I cannot find the amp-hour ratings of the batteries on any radioshack page. Looking up a similar model on newegg.com (surf to here

its shows that a 300W load only lasts 5 minutes. blah. You'll need 6 times the # of batteries this thing has to power your setup for 30 minutes. Bigger UPS's will have more/larger batteries, but you will pay more. Most UPS's are used to provide just enough power to keep the machine alive long enough for you to hit save and shut down (or to clean up the dirty power that plagues most of the world...). Some UPS makers make battery packs that hook to an existing UPS to extend its battery life (you can tell by the big cables they have to use to hook them up together.

If you give up and turn the TV off when power goes out, you'll increase your battery life by almost a factor of 2, with any UPS. But I think you can see where I am going - to keep your TV and computer going during an outage is going to require more than $100 in UPS equipment.

The small UPS you linked would give you enough time to hit save and shut down windows normally (prolly a bit more). But I really don't think that it's gonna last you 30 minutes.

-John

euronatura · #4 06-11-2008, 12:32 PM

MTI/Angel
Thanks for the comments.

Angel as for keeping my computer attached to power I am not worried. It is a lap top that has a battery life of more than 4 hours when fully charged. So that I would keep seperate.

It is mainly the TV and Direct Box along with the EVDO Modem. I may sacrifice the TV part just to keep me running on the modem and Wifi system I have in the house. There I am not worried about the local provider since it is thru the cell system and the cell towers do have back ups in case of power outage.

I guess I am going to have to take a trip in the city and see what I can find that is reasonable priced. What I am trying to avoid is the expense and time to set up a generator that handle all of this.

Iggy

Dee8go · #5 06-11-2008, 12:44 PM

Most of the stores in the Washington DC area have been pushing these as "add ons" to their TV sales for a while now. If you have a lot invested in your HDTV (you know, after you GET an HDTV), it makes sense to isolate it from the power coming out of the wall to protect your investment.

euronatura · #6 06-11-2008, 12:47 PM

No at this moment I do not have lots $$$ invested in the electronics. All the good stuff stayed with my ex-wife. The most expensive part of the system is the 1.5 meter dish on the roof and well, that cannot get fried cause of electrical variances......

powerpig · #7 06-11-2008, 01:18 PM

An UPS is what it is. It's designed to maintain power for a short time so you can do a graceful shutdown to your devices. The unit you linked to won't power them for any period of time. We lost power this past weekend and I was able to hook a TV and DirecTV to a jump box I had with AC input plugs. Worked great for a couple of hours and I even hooked a lamp in. I picked it up on Amazon for around $80. Does a great job jumping the cars too.