Dangerous UPS componants

[Cannibal23]

hello all

just a little question and hopefully someone here knows the correct answer. basicly what im looking to know is what componants are not safe to touch inside of a ups after AC power and DC power are disconnected. i have heard that still some componants retain enough juice to seriously make your day .... well unplesent. was hoping to avoid them but i wont be able to do that if i dont know what parts. transformer? capacitor? what do i avoid touching at all costs?

[calumc]

As far as I know the capacitors are the only dangerous things, they can be discharged by shorting the poles with something like a screwdriver. Just be careful!!

[Luke122]

Agreed, capacitors are the killers. As for shorting them with a screwdriver, I wouldnt do that. That's just me. ;)

If in doubt, call your local TV repair shop; they can likely discharge the components for you.

[Cannibal23]

ok so i will dodge the caps in there... especially the huge blue ones..... shudder... im not planning on really touching any of the solder points on any of this stuff. just want to remove some of the boards temporaraly to do some work inside and dont feel like getting zapped. so i dont have to worry about a transformer inside there? i know there is one its huge but they dont hold any juice right?

[Outlaw]

Shouldn't and you can discharge the capacitors if you want. They should be rated for 12v. You should be able to put a light bulb on it to drain it if you are concerned. When I bought a 1 farad cap for my car stereo, it came with a light bulb to drain the cap.

[Cannibal23]

awesome, thanks for the advice guys. trying to see what i can do to my ups to make it a little more presentable.

[Outlaw]

Cool. Don't forget pictures. :D

[SgtM]

Shouldn't and you can discharge the capacitors if you want. They should be rated for 12v. You should be able to put a light bulb on it to drain it if you are concerned. When I bought a 1 farad cap for my car stereo, it came with a light bulb to drain the cap.

The duh light just went off. I don't know why I never thought of that. +rep

**EDIT**
I should mention that doing any of this is at your own risk.

[Cannibal23]

Cool. Don't forget pictures. :D

i wont forget dude. have to come up with a doable design idea first. there are some physical interfearances preventing me from doing exactly what i would like. beyond that i cant find my darn multimeter so i can start looking for voltages that i want to use.

[Outlaw]

The duh light just went off. I don't know why I never thought of that. +rep

**EDIT**
I should mention that doing any of this is at your own risk.

We all have our moments. :D




i wont forget dude. have to come up with a doable design idea first. there are some physical interfearances preventing me from doing exactly what i would like. beyond that i cant find my darn multimeter so i can start looking for voltages that i want to use.

What kind of PSU is it? And what is your exact idea? Maybe we can throw some options or other ideas your way :D

[TheGreatSatan]

awesome, thanks for the advice guys. trying to see what i can do to my ups to make it a little more presentable.

I thought of that once....

[Cannibal23]

I thought of that once....


yes i remember. it was the spaceballs mod. lone star's ship. i dont think you ever finished it off though wich is a shame i was really looking forward to it

[Cannibal23]

What kind of PSU is it? And what is your exact idea? Maybe we can throw some options or other ideas your way :D

its not a computer power supply its a UPS battery backup system. want to add some lighting in there. just was having a difficult time thinking of where im going to leach voltage to run my stuff from. think i have it now just some fine details to work out now.

[Outlaw]

its not a computer power supply its a UPS battery backup system. want to add some lighting in there. just was having a difficult time thinking of where im going to leach voltage to run my stuff from. think i have it now just some fine details to work out now.


DOH! i did that the other day at work.... UPS...PSU so close. lol. That is cool though. Just use some lighting that uses 120V and a standard outlet. run the outlet to the back of the UPS... Done! lol

[Cannibal23]

ya using the regular 110 voltage incoming from the back would be the normal and easy way. for some reason lately i always pick the hard way. basicly i want to put a cathode tube in there and some leds to light up some stuff. unfortuantely that all runs on DC power. figure i will have to leach into the existing circuts to get some power. i dont want all that stuff on when there is a power outage and were running off battery though so i am thinking on using some relays to do some automatic switching for me. its a little out of my normal relm but thats what learning is about i guess.

fortuantely i have some electronics people here at work that i can bother for answers here and there. as i am the network admin i can just put them on the end of the fix it list untill i get my answers... moohooahahahahhaa

[Outlaw]

From my basic understanding of electronics and transformers. You are going to have to tap into the transformer before it enters any of the circuits (unless you know which circuits stay on when the main power is off). On top of that, you will have to watch out where you tap into the transformer too since (if I'm not mistaken) will have different voltages along it and you can't just splice into the wire going into the board because it might draw too much power and your ups won't work properly or at all. Personally I think the relays might be a little much and just finding the right location to tap into (even though you like the hard way) will be easier and save you a few bucks. Plus, is there even enough room in the ups for relays and lights? Hope that makes sense...it did in my head. :D Good Luck and you are evil!!!


as i am the network admin i can just put them on the end of the fix it list untill i get my answers... moohooahahahahhaa

[Cannibal23]

here is the plan. there is a fan inside used for venting the gasses given off by the batteries either when charging or discharging (not sure yet) and there are some led's on the front panel to show if your on ac or dc. the fan is most likely 12 volts (to be determined when i find my multimeter) and the leds most likely work off of 5 volts (to be verified). i was thinking i could splice in and take my voltage from these areas with out having to learn too much about electronics. the reason i am looking at the relay idea is if you run your cold cathode tube while your running on dc power i think it will significantly impact your battery life. so i figured i would just switch it off automaticly. if you have some suggestion or any info about that situation it would be greatly appreciated. there is an empty cavity in the front half of the ups where i will store the relay. for your information, evil is relative.... ok ya your right im a little evil...

[Outlaw]

What is the brand/model ups? Have you tried looking it up for a wiring diagram or something to give you an idea of voltages or areas to splice into? Again with my basic knowledge and what I think I rememberd correctly (:Dlol) You might be able to use the fan wire, given it is 12v or whatever your cathodes/leds need for a minimum, and run it in parallel (should give you an even voltage to all required items. You would just have to watch your amps. Something like this. http://img2.freeimagehosting.net/uploads/8ccfa509c7.jpg (http://www.freeimagehosting.net/)

[Cannibal23]

thats prettly close to what i was thinking. the only diffrences are that i would wire the led up with the led thats in the front of the case so i dont have to route wires all over. there going to be placed up front anyways. and with the addition of that relay to do the switching for when were on ac or not. im concidering what type of relay to use though. i could get away with a 110VAC rated one and just use the wireing at the back where the power cord plugs in to run the thing. the ups is a Fortress LI 1.3.

[Cannibal23]

man i just had a brain wave here. i must be mental to have not thought about this option before when you were pointing me this way. like you were saying i could hook my devices up by wireing into the back where the power cord comes in. the problem i was seeing was my devices run of dc not ac. so why dont i just go buy a little acdc adaptor that runs at 12 volts and hook it up... for my next trick i will invent the slightly rounder but more complex wheel....

[Outlaw]

There you go. The only part is that, from what you said, there is a cavity in the front. Depending on the size of the converter, you would have to run the wire up to the front of the unit then throughout the ups to get it where you need it. Shouldn't be that bad though I would think. Also, is there any outlets on the ups that just work as a surge protector, not a battery backup? I think some of them will have a couple outlets that are straight through power and will just shut off when the power goes out. If so, you won't have to do the relays, just plug into that. BOOM, DONE! lol Nice thinking.

**Lightbulb!**

Unless you don't have one. You could just take a 12v transformer and cut the end off of it and just use the wires to power up what you need. Again, you would just have to watch the amps.

AC-DC Power Supply (http://www.voltage-converter-transformers.com/switching-ac-dc-supply.html)

[Cannibal23]

ok well i took off one the boards (the one with the big cap) to look at things more closely this morning. also because im going to need to make a whole to route wires through and its a good thing we worked out this ac dc adaptor idea. seems that fan works on 24 volts not 12. unfortunately im not versed in electronics enough to know how to make a voltage devider or what effect that would have on anything else.

about discharging the cap inside the ups. apparently if you read the manual for changing the battery it tells you how to discharge the thing. wich after reading it i totaly should have though of... it goes like this. unplug from wall. disconnect the batteries. turn it on.... tadaaaaaa!!!

[Outlaw]

Imagine that! lol I would just get the adapter and plug it into the back. I'm sure you could find one cheap and have the rated specs you would need leaving you with the know how of twisting/soldering/heat shrink or taping wires together and placement of the items.

[Cannibal23]

i know the adaptor is going to be 12V but i dont know how many milliamps it should be rated for.

[Outlaw]

See what your components are rated at and look accordingly.

Figuring power ratings. (http://www.powerstream.com/Amps-Watts.htm)

For example:
These use +/-3.7W at 12V (http://www.xoxide.com/bluecathode.html), that means for these alone you would need a 12v, 300mA(.3A) adapter minimum (3.7/12). Don't forget about your LED's.

[Cannibal23]

totaly going to check that out!! i have one last question here... ya i know i have been picking your brain alot but here goes. with an acdc adaptor lets say all my devices only want lets pick an arbatrary number here ... lets say 100 milliamps, and the adaptor that i have supplies 300 will i be frying my devices or will they just take what they need?

[Outlaw]

It should just "take/send" what is needed at the components. I have done that with the equipment here. Hooked up ac-dc rated at 12v 500mA to a device rated at 12v 400mA and nothing happened. If you think about it, it is just like your PSU in your computer. You have the 12V rails rated at 25A+ but your motherboard only needs 2A(exagerated). The ac-dc adapter is just a scaled down version of a PSU and in this case only has 1 output which would be equivalent to your PSU with 1 12V rail at 60A. Everything that is rated at 12V and is less then 60A will run without a problem until you reach the units peak output (60A). Then you will start to have problems, ie, burning out the power supply or the equipment not working properly due to not enough power. In short. No, there should not be an issue, BUT if you look on most applications, the required power for the device usually matches the power source. Ex. 12V 500mA connected to 12V 500mA.

**Did a quick google search and was reminded about housing... 100A service to the house, you only use 68A. Nothing blows up. :D

[Cannibal23]

thanks again :-) your very knowlageable. thanks for letting me pick your brain. +rep

[Outlaw]

lol, no problem and glad to help. Make sure we/I get pics when its done. :D

Also... found THIS (http://ths.gardenweb.com/forums/load/electronics/msg01155812860.html) Basically just proves what I said. If you don't want to read it, the person hooked up a fan rated for 12V .48A (480mA) to an adapter rated at 12V .55A (550mA) and has not had any issues.

Good Luck. Thanks for the rep.

[Cannibal23]

ok the worklog is going up now :-)

[Outlaw]

Cool...Can't wait.

[Cannibal23]

worklog is already started and you got name dropped for credit on the power issue. thanks again for the suggestions. heres a direct link

http://www.thebestcasescenario.com/forum/showthread.php?t=12331