Welcome to this emergency battery powered back up project, I designed it to be a back up to power electronic devises if power was removed from the Mains.

The version below is to be powered from a mains adapter for 9 or 12 volts.

Now if you would like to see the emergency battery back up power working see my You Tube video here.

Also see my page here for more Battery back up power supplies run from a mains Transformer

1). Why I designed this simple emergency battery back up design was down to the amount of electronic projects that get designed every year with no emergency back up power this design is to over come that problem.

2). The design is simple to build and the parts are off the shelf component's I designed it so it could be built in to your own electronic projects or as a stand alone devise.

3). Now a quick run down how the electronics work when the relay is turned on this will switch the current from contact 2 over to 3 in the photo above you can see contact 2 is connected to contact 1 which has no connection to it.

4). Now with no current flowing in to the relay the relay is set for a NC Normally closed contact now look at contact 6 this is in contact with contact 5 now the power from the battery can flow in to our circuit powering it.

5). Now when mains power is turned back the NC contact now become NO Normally open now the power flowing into the circuit with the battery is switched out of circuit and the LED goes out.

6) Now the contact from 5 contacts to 4 this contact 4 has no connecter so does not switch in to circuit allowing the power from the mains adapter to power your circuit again till it is removed again.

All the parts are of the self components you should not have a problem getting any thing to build this project.

Now if you have any problems than please do e-mail me at: Anthony@anthony-dacko.net