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is it possible to run AC power Cordless phone by AA battery input power 6 volt 500 MAH? Answered

I have purchase a cordless phone few days ago. its not work when the power down, so i want to run it by AA battery during AC power down. or is it possible to run automaticaly by battery when AC power down.

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NikonDork (author)2009-04-25

I see what hes saying. Basically he wants to beable to still use his cordless home phone when his household mains is out (power outage). The handset itself is powered by battery, but he wants to power the base station. I actually did this myself. I use a VOIP phone system with my modem (that has a 48 hour battery backup system). Since the power in my area is pretty much guaranteed to go out for a few hours during bad storms, I thought it would be pretty useful. Since most cordless phones' charging stations are powered by a wall transformer, its pretty much as easy as making a battery pack that matches the output voltage of the transformer. I wouldn't recommend using AA batteries, but D cells, since they will last longer. What I did was make a 4 cell D battery pack out of a 4 D cell battery holder and a smallish project box. I even added a switch and kept the wall transformer plugged in so I could use the switch to select either AC power or Battery back up. The circuit design for this project is very easy, just remember to match both the size and the polarity of the DC adapter plug that goes into the actual phone cradle.

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atmhoque (author)NikonDork2009-04-25

The adapter of Base station mark 6 volt & 500 MAH but there is no indication of polarity. How I measure it & what is the meaning of size.

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NikonDork (author)atmhoque2009-04-27

I made my battery pack to plug right into the same jack as the AC Power Adapter plug. If you look on the wall transformer itself (the chunky part that goes into the wall). You'll most likely see a little symbol that looks like this

(-) ---------------( · ---------------- (+)

Heres a picture of the same symbol:
http://gravitech.us/MicroResearch/PowerSupplies/WallAdapters/9V-2_1mm-PosCen.jpg

This symbol is letting you know that the tip (the center dot on the symbol is positive, and the collar is negative.

This was just my idea to plug it into the existing jack, rather then open the phone's case.

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atmhoque (author)NikonDork2009-04-27

Hi! Thanks for the advise. The output current of the adopter is 500mah. can I use 4 AA NIMH 2500mah. if possible need any Extra circuit.

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ry25920 (author)2009-04-25

Um... Does it have a wall transformer... Be more specific. If the power jack on the back of it says ?volts. Put ?volts at however many amps into it.

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