dc supply applied to bridge rectifier

hi....! I will be very much thankfull,if someone could help me out with this !:
What happens if a DC power supply is given to bridge rectifier? :?::?r if a dc battery supply is given to adapters(like mobile chargers,laptop chargers etc....)
(actually i want to give a dc battery supply to mobile phone charger when there is no current) 8-O8-O

It works just as though it was AC, the bridge is there so the input can be either polarity as would be the case from a wall outlet. In fact, you should be able to connect the DC either way around.

That was the good news - now the bad news. Many chargers and adapters do not have a bridge rectifier at their input pins but a transformer instead. It you connect DC to one of these it will burn out. also you have to be careful about how much DC you use instead of AC. Some cheaper adapters rely on the AC power (in Watts) being lower than the same voltage DC and push their components to the limits of their ratings. If you use DC they may generate more heat and become unreliable.

Your best option is to buy a car adapter and connect it to a car battery. Don't be tempted to just connect voltage directly to the phone/laptop, the charger circuit inside the adapter is necessary to regulate and limit the current at the output.

Brian.

can i connect

with

can i connect this directly to the phones(not with the same battery but a battery with suffient voltage)

If I understand correctly from the first post you want a battery and charger connected together and to the phone, such that the battery takes over when the charger is switched off?
If so that needs diodes in the output of the charger and the output of the battery to prevent the charger connecting to the battery and the battery feeding the charger (i.e. isolating the two power sources from each other but not the phone), but both able to supply the phone.

If however you want to battery power the phone as per your second post, there are some low cost USB charger versions on the market that take a single AA cell with an inverter to get to the correct voltage. These will probably be more cost efficient than the 9V layer battery solution in your picture. But this does require unplugging and reconnecting the desired power source and that USB is a suitable charge input for the phone.

My suggestion would be:
Dont try this. There must be a circuit which should stop delivering current to your phone once its battery is fully charged. Overcharging results in very critical situations.
https://en.wikipedia.org/wiki/Battery_(electricity)#Overcharging
Be advised !
Further its upto you if you wanna try !

i guess you can

(actually i want to give a dc battery supply to mobile phone charger when there is no current)

Click to expand...

it will not work on 12v dc higher dc voltage required. and the charger should be a smps based not iron core transformer
based.