6volt backup battery circuit with auto charger

saad ahmed khan

hello every one!

due to frequent power outages in my area, the lan switches at different locations stop working.

so either the light is out or the switch is not working which is really irritating.

so can some one help me with a circuit that can supply 6 volts for the switch in case of power outage?

what i want is a circuit that runs of ac and charges a 6v dc battery while simultaneously running the 6 volt switch. when the light goes out the battery then should power the switch.
also their should be some way to prevent the battery from over charging.

regards,
saad

NoTime

Have you considered standard UPS equipment.
Might be cheaper than making your own.

mgb_phys

Or just a 6v lead acid battery (eg motorcycle battery) and a charger.
Most decent chargers have a floatmode where they keep the battery topped up.
Your equipement would have to be able to withstand the 7V the charger would supply while charging but most will.

+ Smaller and wastes less power than a UPS+6v dc adaptor.
- Might be tricky to find a 6V battery with a large enough capacity if you need it to run for many hours.

saad ahmed khan

the switches are on poles about a km apart. i caNT USE one ups and drag its wire for the whole distance. i want a stand alone system

i intend to use a bike battery. i want to make make own charger though coz i cant find any good quality ones locally.

mgb_phys

If the hardware can survive having slightly more than 6V supplied to it I would just use a 6v lead acid battery and a solar panel to trickle charge it.
Are you in a country where solar power is likely to be practical?

NoTime

It may be possible to use line power for the switches.
This way you only need one power setup.

saad ahmed khan

solar power is in plenty.. solar cells are NOT.

i want to use the mains to charge the battery as well as run the switch.

and when the mains fail then i want the battery to run the switch..

you people are not getting my point exactly.

NoTime

If what you are looking for is a fancy battery charger, you could look at this
http://www.rason.org/Projects/gelcell/gelcell.htm

You would need to alter it some for a 6 volt battery.