Introduction: Phone Charger

Picture of Phone Charger

This is a simple phone charger that is using an 7805 voltage regulator.


7805 voltage regulator

small aluminum plate (38x27mm)

thermal Paste

USB female socket

terminal block (for power connection)


2x 10uF capacitors (SMD)

180 ohms resistor (SMD)

red LED (SMD)

9V connector

JB weld

Varnish (coating the PCB)

For PCB building:

I used toner transfer method(laser printer, glossy paper and ironing)





soldering station



SMD Flux


Use Design Spark PCB (free: to open the .pcb and print with the Top Copper, Bottom Copper, Board Outline and all colors black selections made!

Step 1: Building the PCB

Picture of Building the PCB

When building the PCB make sure that your aluminum plate will fit.

Cut the PCB (39x44mm)

Use toner transfer method to make the PCB, after etching use fine sand paper (or acetone) to remove the toner

and clean with alcohol.

Drill holes in the PCB.

Drill a hole in the aluminum plate to mount the 7805, use thermal paste.

Solder the components, begin with the SMD components (use SMD Flux) then solder the USB connector, terminal block and finaly the 7805. Screw the 7805 to the PCB.

Connect the 9V connector to the terminal (red to + black to -), the 9V battery can be changed with a 12V or an 12V car plug for in car use.

Use JB weld under USB connector so it doesn't move.

For protection (anti corrosion) use the transparent varnish, spray the PCB 2-3 times from 30cm distance.

Step 2: Testing

Picture of Testing

Connect your battery or accumulator (9V-12V).

The red LED should light up.


You should get around 5V output and 660mA (0.66A)(depending on the phone you are charging).

The best result are from any 7.4-12V, but 2-5(or higher) amperage accumulators such as car(best results if used in car). With my 600mA 9V accumulator i have ~1h of power to the charger.

Make sure that the amperage doesn't exceed 1A.

The aluminum plate may get warm or hot, this is normal since 7805 is dissipating heat.

Have a nice day.Thank you!


Matīss Jēkabsons (author)2014-07-03

Hmm... i wonder - how to make such a charger but with 2.1A output?

Mock5 (author)Matīss Jēkabsons2014-07-03

That can be done with an LM338.It can handle up to 5A, but you need to use an online calculator to find the right resistor so it outputs 5V. (

Matīss Jēkabsons (author)Mock52014-07-03

And as i understood, i need to thing about how to cool LM338 because of heating, right?

Mock5 (author)Matīss Jēkabsons2014-07-04

Yes.In the datasheet you ca see how much power it dissipates per watt.

Mock5 (author)2014-04-29

It best work with li-po accumulators such as phone ones 2connected in series or for more amperage use groups 2 in series connected in parallel with another 2.You need at least 7.4V and preferably 1A or more.

Mock5 (author)Mock52014-04-29 great tutorial.

Aashay Sathé (author)2014-04-29

Capacitors can't be electrolytic, right?Or are they ?:O

Mock5 (author)Aashay Sathé2014-04-29

The caps that I used are not, if you want to use electrolytic ones make sure to connect it at the right polarity.

efahrenholz (author)2014-04-02

Good job on the circuit board, but abraham lincoln wants his 7805 back.

Mock5 (author)efahrenholz2014-04-02

It is LM7805, so i won't give it back :D

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