Team-BHP - Smallest portable nokia charger

Smallest nokia charger, u can even charge you mobile while jogging or when you are stuck in a jungle. I made this circuit when i heard of IIT'ians charging their nokia cell phones with portable windmill.:mad:
It costs around 35Rs. plus you need 9 v battery which cost aroung Rs18 each.
A single 9v dry cell can be used for only a little more than 1 charging cycle only (aprox.)

Well this is my cell charging on my new charger.
The curuit is quite small n easy, needs no explanation. The 7806 steps down the 9v from battery to 6 v. I attached a small capacitor just because i love my phone( to pull down any spike if produced to pluad connection n disconnection.
For more pics. circuit and details check this my link-
http://www.geocities.com/melvinisbac...okiacharge.htm

For moderators- sorry i dont know how to make a thumbmail. any way it is just a small 25kb pic.

Nice work amit :Cheering:

One question though since you are stepping down voltage to 6V why not use 4 AA cells connected in series ?

EDIT: Can you put resistance instead of transformer?

ADYA33:
4 AAA cells can be connected but i dont think they would take the load easily. tehy will not be able to provide enough current plus 4 aaa cels will cost around 28rs. 9 v battery is smaller and cheaper.
When we connect a complety discharged cell the voltage across battery reduces to 5-6v instead of 9V this shows that load is quite high.
b the way there is no resistance or transformer in circuit.

I heard this charger is also available in palika bazar new delhi.

Quote:

Originally Posted by amit1101

by the way there is no resistance or transformer in circuit.

voltage regulator. my mistake
with resistor i was saying you can easily reduce voltage to a suitable value.

Quote:

Originally Posted by adya33

voltage regulator. my mistake
with resistor i was saying you can easily reduce voltage to a suitable value.

Taking this into deeper electronics i would say
resistance are generally used to reduce current and not voltage. If your load is constant then only you can use resistance for voltage regulation. One more thing resistance tends to be lossy i*i*R losses.
transformer and SMPS are better as they are less lossy and theier o/p voltage does not varry with small change in load
7806 is not just used here to reduce 9v to 6v. I am regulating the voltage so the phone is not damaged. Hope this anwsers what you meant to say.

Quote:

Originally Posted by amit1101

yup.
thank you for explanation :thumbs up

Novel thought.. but if you are interested in using it, please be warned that the 9V PP3 battery will be drained in no time.

Some improvement tips.
- Replace 7806 with a Switch Mode Regulator since the Linear Regulator(78xx) is notoriously inefficient.
- Run the switch mode regulator off 4-6 AA cells

For people using Sony Ericsson Mobiles, the charging voltage is 5V only

Quote:

Originally Posted by Digital Vampire

When we connect a complety discharged cell phone the voltage across battery reduces to 5-6v instead of 9V.:Shockked: so there is not much loss in 78XX, plus Switch Mode Regulator will increase size.
Sony Ericsson people can use 7805 instead of 7806

Quote:

Originally Posted by amit1101

When we connect a complety discharged cell phone the voltage across battery reduces to 5-6v instead of 9V.:Shockked: so there is not much loss in 78XX,

Amit, The reduction in terminal voltage is simply because the poor 9V PP3 is unable to handle the charging current requirements. Try doing this with a packs of D or AA cells and you may not see any drop in voltage.

Agreed, the size will go a bit up with switched mode regulators.

Dude i don't know if people are already producing such equipments or no but if possible get this idea of yours patented and trademark. and if possible sell it to some company you might just get some good mullaahhh

I find this very usefull for those traveling long distance in train, where we have lack of charging optiones for our phone. and its the good way to charge.

One more thing How much time and battery dose it take to charge a phone from 0 to 100 % charged battery.

One more and the last thing. is this 78XX IC that you are mentioning available in market.

These type of devices are ok for energency use to make a call . I have one that takes 4AA batteries. They are not very usefull to charge a mobile. You can buy proper booster packs for such purposes but they are costly.

Digital Vampire
i'll try 4* AAA cells as soon as get some spare time. lets see if they can provide sufficient current.

sinner
Yes 78XX is easily avaiable but dont goto a shop keeper and say you want 78XX, say 7805, 7806, 7809, 7012 XX= voltage
i dont think this is a great enought to be patented and all. Now i have heard of these available in markets as well.
It takes around an hour to charge the cell, but it never charges fully as the current in battery falls quite low after some time. If a cell is fully discharged we can just connect this thing and make a call.

hey
you people heard of that thing which which u can control u r PC with any remote control.
its half the size of u r thumb costs around 50Rs. and you can shut down restart your PC or launch winamp or media player and change tracks and pause n forawd , suspend monitor etc. ??
check this link
http://lnx.manoweb.com/lirc/?partTyp...e=introduction
or serch google for PC IR remote u'll get endless results.

I do use my pinnacle remote...
but only with some limitiations (coz of pinnacle software)

Any other good IR Remote softawre for windows?

I use my phone too.... it has IR and remote software installed.