• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Mobile charger

Status
Not open for further replies.

yasir_ali

New Member
Hello EveryOne,

I want to design a mobile charger for my mobile that would charge the mobile's Battery through 9v DC Battery. I am including the block diagram about what i think that this could be done. please find the attachment and reply me what you people think that this could be done.?
Thanks a lot
 

Attachments

Hello EveryOne,

I want to design a mobile charger for my mobile that would charge the mobile's Battery through 9v DC Battery. I am including the block diagram about what i think that this could be done. please find the attachment and reply me what you people think that this could be done.?
Thanks a lot
Hi yasir,
I dont understand that why one would want to convert dc to ac and then again to dc.I find this very interesting thats why could not stop myself from replying.I am certainly not an expert so plz take it easy if I am making a weird argument.Hope the experts here can help.:)
 

Diver300

Well-Known Member
Most Helpful Member
A mobile phone is normally charged at 5 V. A switch mode buck regulator will be more efficient than a linear regulator.

Switch mode regulators sort of convert to AC and back to DC, and the extra complication can be worthwhile if there is better efficiency as a result.

Most car adaptors for mobile phones are switch mode regulators so you could probably use one of those as is.
 

yasir_ali

New Member
But i want to design my own charger. check my clock block diagram and tell me am i right or going wrong?

@legend killer
what do you want to say? please say clearly.
 
@legend killer
what do you want to say? please say clearly.
Hi yasir,:)
I am studying electronics and I have never heard about any circuits,at least uptil now,that converts dc to ac and then ac to dc.So I just wanted to say that I could not help you but our expert forum members may be able to help.
Diver 300 gave a little bit of explanation.
Switch mode regulators sort of convert to AC and back to DC, and the extra complication can be worthwhile if there is better efficiency as a result.
 

audioguru

Well-Known Member
Most Helpful Member
Your cell phone needs 5V at 800mA. You could make a buck converter that will provide 5V at 800mA from a 9V battery but the current from the 9V battery will be about 511mA. Then a new little 9V alkaline battery will be at 7V in about 10 minutes when its current will rise to 700mA. Then the battery will be dead in another couple of minutes.

But how long does your cell phone need to charge? A couple of hours?
 

blueroomelectronics

Well-Known Member
Energizer makes a cell charger that runs on a couple of AA cells. It's also cheaper than building one and will not damage your phone.
 

ben7

Member
Energizer makes a cell charger that runs on a couple of AA cells. It's also cheaper than building one and will not damage your phone.
Good point!

You could use some AA or C batteries that will last much longer than the 9Vs AAAA batteries!

-Ben
 

yasir_ali

New Member
ok.Thanks for your replies. and thanks for the very good point. now i think i should use 3 AA Batteries because they all will make 4.5v and thank you would be fine for charging the mobile. what you people think? or should i use 4 AA Batteries to give the Buck circuit supply of 6v?
 

audioguru

Well-Known Member
Most Helpful Member
You need 5.0V to feed the charging circuit in the phone.

Three alkaline battery cells make 3V or less when used for a while which is much too low to charge a cell phone.
Even when the battery is brand new its 4.5V is probably also too low.
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top