Hi
I need some help! With my project
I have a 12 volt feed from a Vehicle battery that I have fitted with a Regulator Adapter, Step-Down to 4.5 volts, what I need is to run a battery pack of 3 AA batteries that are only used if the main supply is disconnected.im not sure weather to use a relay,
Any help will be appreciated.
Cheers
Clive
Hi
I need some help! With my project
I have a 12 volt feed from a Vehicle battery that I have fitted with a Regulator Adapter, Step-Down to 4.5 volts, what I need is to run a battery pack of 3 AA batteries that are only used if the main supply is disconnected.im not sure weather to use a relay,
Any help will be appreciated.
Cheers
Clive
A single diode is dependent on the incoming power supply having reverse blocking, and as we don't have a circuit of that PSU you can only use two diodes to make sure it works correctly.
Hi
Thanks for your replies,im a bit of a novice at this’but learning fast’
Is this what you mean about the Diodes and are they in the right place, or is this not right at all, I was wondering if the 3AA Batteries would be getting used as well as the main supply ( would they be going flat as if they were being used).
Thanks again
Clive
That's right, the main supply needs to be a little higher voltage than the battery supply, so that power is drawn from the main supply - as the main supply drops lower, the battery takes over.
Hi
Just one more Question...
If the Main supply is a constant 4.5 volts and the battery backup is slightly higher, does this mean that that the appliance will run off the Battery Backup untill it drops below the fixed main supply, then if' the main supply is stoped the battery will take over untill the main is reconnected...
Thanks
Clive
Hi
Just one more Question...
If the Main supply is a constant 4.5 volts and the battery backup is slightly higher, does this mean that that the appliance will run off the Battery Backup untill it drops below the fixed main supply, then if' the main supply is stoped the battery will take over untill the main is reconnected...