Need Help with a relay Circuit


Old 07-12-09, 12:59 PM
CircuitBreaker's Avatar
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Need Help with a relay Circuit

I have frequent power outages (I live in a rural area outside a city) I have a CyberPower UPS but what I want to do is have a lamp come on if I lose power and then go off when power restores. I don't know alot about electronics but I think what I want to do is simple right? Here's what I think I need to do but again I have little electronics knowledge I have a extra 5VDC/12VDC transformer that will be plugged into the surge only (When the power goes out those outlets loose power) and then a relay comes in to switch on the lamp (9W 120VAC CFL) when the the DC 5V or 12V goes dead the relay will switch on the lamp which will get power from the battery backup outlets. I just need help with what kind of relay to get and how to wire the high and low-Voltage parts
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Old 07-12-09, 01:14 PM
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Take a look at this post..would it work for you?
Old 07-12-09, 01:19 PM
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Hi CB, I know it is interesting to create your own designs, and what you stated can be made to work, but you can buy one for $15. Just do a search on "emergency lights". They come with their own batteries so no load on your ups and you can install them anywhere.

Anytime you wire up something as you propose, you accept the liability of anything that happens. A UL approved package doesn't guarantee that things won't happen, but it usually says the insurance will cover the damage.

Be Safe,
Old 07-12-09, 05:10 PM
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It's extremely simple to wire a relay for what you want but I agree with Bud that the simplest is to purchase a power failure light. Why waste that wallwart you have and have to purchase a relay, enclosure, receptacle and spend an hour building this thing when you can pick one up for about the same price as just the parts?

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