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Emergency cell phone (NOKIA 201) charger from 7805 regulator circuit?

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Willen

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Somethime there is not electricity long time due to lightning. Nokia said: 'Do not use others' charger!'

Can't I charge it from 12V battery using LM7805 regulators circuit? Why nokia said so?
 
Nokia sais that so that you can´t sue them beacuse they didn´t tell you so, similar to manuals from a microwave telling you not to dry living animals in it.
Is it possible to charge it through usb?
 
There's also a limit to the charging current the batteries can handle. You can charge from a 12 V battery using a 7805 if you can limit the current to a safe value.
As kubeek said, Nokia intends to protect its market like HP, Samsung, Sony, . . . . what have you!
There are car chargers plugged into a cigarette lighter for powering almost any Cellphone, Laptop, Tablet, .....

Ramesh
 
...
Is it possible to charge it through usb?

Good idea! If you can get a USB charger lead for any device you know it can be charged from regulated +5v through that lead. That covers the "will it work" issue.


... similar to manuals from a microwave telling you not to dry living animals in it.
...

Hmm, so it's ok to dry dead animals in the microwave? Cool.

Just a short question; does the "dead" bit refer to when they went IN the microwave or when they come OUT? Because I think I'm seeing a shortcut... ;)
 
If it is a Nokia phone with a USB charger input, then design a power supply that outputs a fixed 5.0V and hook it up to a TYPE A USB socket. Plug the standard USB lead into the USB socket and the other end into your phone and you will have a charger. (the cable acts as an adaptor between the USB plug and the myriad of different USB sockets on phones)

If it does not charge, connect the 2 data lines (at the Type A connector) together.

USB should be 4.5 - 5.5V, so adhering to this voltage will make it compatible with any USB chargable device.
 
It has no USB charger, It has its own charger with small pin.and charger has been rated: 5V DC 450mA. I didn't test the real output voltage of charger.
 
The problem is if the charger has a multi-pin plug.

It's common to have 3 pins on appliance chargers; 2 for power and the 3rd pin is some type of communication signal to start the charging process.

These 3 pin plugs LOOK like 2 pin plugs, with an outr ring and inner pin. But the outer ring has an inside and ourtside wall, both are separate conductors. The inner pin is often the communication pin.

If your charger has exactly 2 pins only, and makes regulated 5v ALL THE TIME, then it looks likely that you can use any regulated 5v supply to charge your phone.
 
i have a nokia c3 with a charger that shows same values as yours and is only 2 wire, if it is the same it will work, since we are just looking at the power supply, and not the charge circuit

typically with my experiences on digital devices usually i see the lithium batteries inside , along with the balance charging circuit being built in, having said that, what you are looking at is just a power supply and not a charge circuit, it should work as long as you are powering the charge circuits with the dc input required.

also in my LIMITED experiences the hardest part about mixing chargers is finding a plug that fits
 
Nearly all mobile phones have the charging circuits built in. So you only have to supply the phone with what the wall plug will give out. This is normally 5V @ 1A.
Most wall chargers have the minimal electronics inside to pass safety rules and are pretty crude.
However not all phones can be charged via USB, but by their own external input. There is little reason why this cannot be derived from USB as long as you don't overload the USB port.
 
In simple- it has 2 pin only!

I think if charger's out is 5V then I can charge by 5V regulated DC. And I think ampere (high ampere) will not be harmful if I used recommended voltage (5V). I will test the out voltage of my charger, if got 5V reg. then will make regulator using 7805 :)
 
***** (double post)
 
OH NO!
7805 burned my thumb, wufff....!
Is 7805 not able to conduct 0.5A for cell phone charging??
Circuit and regulator is good but when I pluged my cell phone it starts to heat immediately and it's very abnormally heats!
 
If you fed the 7805 with 12 volts it will dissipate 3.5 watts (7X.5). If it is the TO220 package without a heatsink it's temperature will rise about 62C per watt. It will need a heatsink.
 
I used small heathink later but it is also hot! I think in such horrible heat the IC (7805) will die soon.

Should we have to calculate including dropout voltage for power dissipation of this IC? (like 7V for 7805, 11V for 7809 and so on?)
 
I used small heathink later but it is also hot! I think in such horrible heat the IC (7805) will die soon.

Should we have to calculate including dropout voltage for power dissipation of this IC? (like 7V for 7805, 11V for 7809 and so on?)

hi,
Its voltage across the 7805 times the current which gives the watts,

So if you have a 12Vdc input to a 7805 regulator passing 0.5A its 7V * 0.5A = 3.5Watts.

The 7805 will work with as little as 7.5V input, it requires at least 2.5V higher in the input than the output voltage.

If you have some power resistors you could drop say 4.5V at 0.5A across the resistor [ on the input side of the 7805]

So the power resistor would dissipate 4.5*0.5= 2.25watts [use a 5watt resistor] and the 7805 would dissipate 2.5v*0.5 = 1.25Watts.

It would still require the heat sink but would not get so hot.

E
 
All is not quite well in this thread. There was a thread recently that had a lot more info.

There is a lot involved with USB charging. Motorola, for instance has resistors in their USB cords that allow a larger charging current, otherwise you could be limited to 100 mA.

Apple has made it so you can get an excess of 1A from USB.

I actually THINK your best bet would be a 1 A cigarette lighter charger and a USB cordset for the Nokia Phone or a cigarette lighter charging adapter for the phone for two reasons:

1. Your not violating any warranty issues and if there happens to be the shenanegans of pull up resistors on the data lines to determine charging current, your covered.

2. The 12 V cigarette lighter will likely have the USB charging limitations/handshaking already built in, so if it's possible to charge at a higher rate, it likely can.

Look here: https://en.wikipedia.org/wiki/Universal_Serial_Bus#Power and pay attention to the charging section.

I have a CIG lighter adapter that can interface to micro and mini USB. That adapter I use for my GPS, Cell and handsfree in my car. My car cannot charge unless the ignition is on.

There is another car that has power to the cigarette lighter all the time. I use it to charge my cell. There is a handsfree device also. Not sure what connector it uses.
This is basically so I wont be without power on the cell.

I have a charger near my bed that I can adapt to the micro and mini connectors and I have a floating charger that I primarily use for the cell.

To further aid charging of all devices, I bought two universal chargers and spare batteries which are really cool. You can place nearly any Li battery in it using adjustable clips without regard to polarity. Charge state and voltage are shown on a numeric display. This little guy: **broken link removed**

My current phone yells at me when it needs charging. The LED surrounding the charge port starts to blink.
 
hi,
Its voltage across the 7805 times the current which gives the watts,

So if you have a 12Vdc input to a 7805 regulator passing 0.5A its 7V * 0.5A = 3.5Watts.

The 7805 will work with as little as 7.5V input, it requires at least 2.5V higher in the input than the output voltage.

If you have some power resistors you could drop say 4.5V at 0.5A across the resistor [ on the input side of the 7805]

So the power resistor would dissipate 4.5*0.5= 2.25watts [use a 5watt resistor] and the 7805 would dissipate 2.5v*0.5 = 1.25Watts.

It would still require the heat sink but would not get so hot.

E

little confusing!
Um... And if I used 9V supply for 7805 to produce 0.5A than
4V*0.5= 2watt?

Here 4V= supply voltage minus output voltage?
 
Why not just use a USB/Solar powerpack and USB multi charger cable like this
**broken link removed**
Don't have a pic of the power pack I used, but it is about the size of large cellphone, and can be charged via PC USB, AC USB adapter, or solar power.
Used a rig like that yesterday at my step-son's graduation to recharge his grandma's phone so she could take pictures.
 
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