Portable USB Charger (Version 2.0)

The project name says it all. It is a device that will charge things like Ipods, PDAs, other other devices that plugs into a USB to charge.

Step 1: Supplies

The parts needed for this project are all in the second picture.

You will require:

LM or MC 7805 +5VDC Voltage Regulator
Type-A Female USB Port
100 UF Electrolytic Capacitor 10-50v
0.1-0.5 UF Capacitor  6-50v (any type would do)
150-160 ohm Resistor (optional)
9V Battery clip
2.2V 20mA LED color of your choice (optional)
Unprinted circuit board
ON/OFF Switch (optional)

These parts can be easily purchased at your local electronic store, like Radio Shack. Or you can buy them online at:
http://www.digikey.com

Regulator:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=LM7805CT-ND

USB port:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=151-1080-ND

100 uF Capacitor:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=P12392-ND

0.1 uF Capacitor:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=399-4151-ND

Comments

[imx3110]

Hello sir,
I have a doubt regarding PCB etching provided.
The 7805 has the 2nd terminal as ground and 3rd terminal as output but the design given seems to have 2nd terminal connected to output and 3rdterminal to ground(As it seems to be connected to -ve terminal of battery). Can you please provide an explaination where I could've gone wrong in the interpretation?

[jrv411]

GENIUS!

[adityam]

Hello SIR ,
Can u tell me what is highest voltage that can i give as an input to this charger and who many cell phones can it charge is 9 V is supplied as input????

[sneekhra]

hello sir plss give me the details of the changes i have to do if i replace the 3.7 volt battery instead of 9v battery to get a good charger

[skeletonkey124]

FOR APPLE USERS:
USB Female hubs have 4 prongs as you've probably noticed. the right and left ones are ground and power respectively. The middle ones are the Data + and the Data -. for 99% of the phones out there you don't need to attach anything to the data ports. Apple products however have a strict security feature that will not allow one to use home made chargers.. you can hack this by "tricking" your apple product into thinking that it is actually plugged into a laptop. This can be done by splitting the power from the Voltage Regulator into two wires and attaching them to BOTH of the data ports WITH 100 ohms resistors (on each port). It's IMPORTANT that you use the 100 Volt resistors because you can blow your iphone/ipad 's usb port otherwise and never be able to charge it again. Good luck with your chargers!

[Themaxim]

Does it work on ipad

[kaushal.1214]

I also built the same, and after 5-6 secs my phone shows warning msg "NOT CHARGING! BAD CONTACT". Problem is not with the cable as i have already checked. And I don't know what's the problem with my ckt. Plz help!

[wladicus]

If a capacitor is "Leaky" or damaged then a short circuit or intermittent short circuit to ground condition is created and the 5 volts at the regulator output will also be grounded and the output would drop to 0 volts.
If the capacitor at the output has an intermittent or 'slow leak' then that could why after 5-6 seconds your phone shows a "NOT CHARGING!" message, because at that moment the capacitor has shorted to ground and the output voltage has dropped to 0 volts.
That is one quite likely answer. These conditions are sometimes tricky to find with voltage measurements if the capacitor does this only sometimes. The best solution is to replace the capacitor or remove it completely and see if the charging is restored.
Hope this helps,
walt

[wladicus]

1. When you say "I also built the same" are you referring to the author's 7805 circuit or are you referring to the 'car lighter' charging cable idea that I described?
2. In either case - Are you reading an output voltage around 5v DC from the end of your cable that goes into your phone (before you plug it into the phone)?
-walt

[kaushal.1214]

I was referring to the 7805 ckt. which author described. and yes i have also checked the output, which is approx. 5v. I'm using 9v battery as input, capacitors of 100uf of 50v n other 0.1uf ceramic type of orange colour.
I also want to know, Is it ok to directly attach the output of 7805 to the phone?

[wladicus]

If your phone is designed for a 5V charging input then the direct output from the 7805 will work. If the output voltage of the 7805 is around 5v DC and steady (ie. the 7805 is not damaged).
A capacitor of 10uf or greater is sometimes added at the output of the 7805, and sometimes even another capacitor of about 0.1 uf is also added.  The function of the capacitors is to "smooth out" the 5 volt DC input by shunting spurious frequencies to ground. You would need an oscilloscope to actually see these 'spurious' frequencies riding on top of the  5volt DC signal.  They are usually created by the regddulator circuitry or any other nearby high or low frequencies which are always present in today's highly concentrated 'air waves' signal grid.  The larger capacitor shunts or pulls the lower frequencies down to ground potential, and the smaller capacitor shunts the higher frequencies to ground.  Most of the time you can eliminate these capacitors, but if you look at the spec sheets for the regulator you will see their suggested test circuits using capacitors for this purpose.
Capacitors are also used to 'build up' and store electrical charge, but that is not the main function of the capacitors in the regulated circuit design.

[One.]

hey thanks for this, I made one and I also came up with a better idea:

[wladicus]

Did you use a 7805 in this design? - Spec sheet indicates a minimum of 7v input.
4 AA cells = 6 volts DC... so was your regulator a LDO (Low Drop Out voltage) type?

[Euticus]

Some regulators REQUIRE a cap on the output to guarantee stability. Check the datasheet.

[One.]

then this wiring diagram would REQUIRE you to buy a stability guaranteed regulator ; )

[snowluck2345]

not gonna work, 6 volts is too low for a 5 volt regulator, epsicialy once the batteries get down to 4 volts

[One.]

errr...
that picture was supposed to have a 9 volt battery but I must have messed up somehow. oh well!

[emaylas]

cani change the battery x4 aa bateries to 9volts batt ?

[qquuiinn]

The 7805 can take anything from 6 volts to 35 volts

[One.]

yes. it doesn't really matter, but if you want to use the battery's full "energy", this is not a very good way to make one. the 5 volt regulator just wastes the other 4 volts as heat, so its as if you were charging something that was 9 volts instead of 5.
its really good for a quick charge, though, but be sure not to leave the battery in when you aren't using it.

[emaylas]

it works ?? ...

[One.]

hmmm. very much the same question, but with less question marks!
yes! of course!

[emaylas]

it works ????????

[froggyman]

While that will work, it will not give you protection from voltage jumps. Thats what the caps are there for.

[meshein]

For a 6 volt input, where would capacitors go? and what type of caps are needed?

[froggyman]

It doesn't really matter what caps you use, in reality you don't even need them... they are just a nice to have as a little "surge protector" for the voltage as the caps help regulate this voltage by storing and releasing when necessary. Plus they are cheap and could potentially save the device you have hooked up to this.

You can *NOT* use a 6 volt input for the 7805 5V regulator as that regulator needs to have atleast 7 volts to work well. I'm not sure what input you are planning to use, but depending on your space something like two 6v lantern batteries in series (have one of the batteries positive + terminal connected to the other batteries negative - and use the remaining for your power of 12 v ) or you could use 6-8 AA batteries for your power source for the regulator.

[ik110]

Hi,
Iam very much interested in making the charger but iam a totally novice when it comes to PCB and itching and cutting them nor I have any knowledge of caps or resistors... can any one load video of the entire process please >>>>

[m1s73r]

So, first of all I think making this charger isn't a good idea for you, because this is a little bit harder as maybe other Projects. You should start with something easier, with less electric parts.

The PCB isn't really necessary because you can also use a breadboard or something. I use a perfboard and it works great.

Caps (capacitors) can store energy for a time, such as your computer does.
Resistors are like a dam, they stop the energy or convert it to heat.

I hope I could help you a little

[qquuiinn]

BTW, the PCB makes it easy to connect stuff and is worth the extra minute that it takes to Dremel the board and drill holes in it.

[idsonic]

pls can i get every thing about this project? including the write up

[idsonic]

pls can i get every thing about this project? including the write up

[bbeyzat]

where to find the board or what else we can do

[qquuiinn]

Radio shack

[davelectronic]

You need a heat sink to your 7805 regulator, add one silicone diode to ground to push the voltage up 0.5 volts or so, your design will drop below 5 volts.

Alternatively do away with the whole thing, use a 4 x AA battery holder for alkaline cells = 6 volts, forward bios i silicone diode to reduce to approx 5.2 volts and a lot more current, a 9 volts only about 70mA .

[qquuiinn]

Smart, yet a diode made out of silicone would be all rubbery. It's silicon that your trying to say

[freedom25]

sir can ask something regarding an output of 4.5 volts from a lm7805? how can i reduce it from 5volts to 4.5volts? the input is a 9volt battery, can i ask what modification can i do? i'm new in this electronic devices, can u send me some circuit diagram, thanks sir, here's my email [e-mail]

[GoodAtIt]

You cannot get an output for 4.5v from the LM7805. You can add a diode on the output to drop the voltage a little, but that depends on the diode you use.

You can also use the LM317 to obtain a regulated output of 4.5v.

[tdobbins1]

In a project like this one. They said to connect the 2 data pins on the usb so it can trick the phone to charge. Do you know any thing about if that is true or what will happen if you connect them?

[qquuiinn]

I would recommend using a resistor to jump the two data pins. If you just outright connect them, the device will malfunction

[iApple guy]

Most iPods, iPads, and iPhones will need this connection in order to charge. If you do not do this to your iDevice it will not charge. And to answer your Queshton that is true.