emergency light circuit help

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snazi

Joined Mar 23, 2010
3
I wana build the this emergency light with a few modifications as i'm new to electronics I need help in the modifications

here's what I want:

I need to build the emergency light as small as possible so can't use the transformer,can somebody provide me with a transformer-less solution to convert 220v ac to 9v dc 500ma ?

the battery specified is a 6v 4.5Ah battery,as the build needs to be small so can't use an sla battery because of its size are there alternatives in a small size i.e in lithium-ion ?
 

retched

Joined Dec 5, 2009
5,208
Why not use a wall wart? The wall plug in transformers, then run a wire to the device. Like a cell phone charger or the such. Instead of having the transformer in the cellphone, they put it in the 'wall wart' and you plug it into the cell phone.

As for batteries, use a niCad or NiMh 9v.. or 4 AA, C, or D size to get ~6v The larger, the longer it will last.
 

SgtWookie

Joined Jul 17, 2007
22,210
It has to have isolation from mains power.
It cannot be made safe without isolation, using a transformer.
If you want to make the transformer small, you will need to make or buy a switching power supply. This will be quite a challenge for a newcomer to electronics; perhaps too much of a challenge. Retched's wall-wart solution is the inexpensive and safe way.
 

retched

Joined Dec 5, 2009
5,208
What is the power source? You could tap into it if there is an outlet on the same circuit and use a 9v regulator IC to power the charger. Then when the power goes out, it runs off the battery, and when it returns, starts recharging the battery
 

Thread Starter

snazi

Joined Mar 23, 2010
3
What is the power source? You could tap into it if there is an outlet on the same circuit and use a 9v regulator IC to power the charger. Then when the power goes out, it runs off the battery, and when it returns, starts recharging the battery
dude all I want is a circuit for converting 220v ac to 9v dc 500ma without using a transformer.ever opened an led emergency light ? there's no wall wart or transformer in there just plugs directly to the power socket :S
 
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