survival usb charger

8/13/2019 Survival USB Charger

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Survival USB Charger: Use any power source to

charge your smartphone

You forgot your power adapter for your cell phone? Or there is no electric socket available?

But you need to charge your smart phone urgently?

Let's build a USB Power Adapter, you can use anywhere! So you'll be prepared for an

emergency!

Just connect this helpful gadget to any rechargeable battery and charge your phone. Even a AC

voltage source like a table lamp will work!

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Step 1: Parts list


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You will need:

- voltage regulator L7805CV

- rectifier, min. 1 A

- capacitor, min. 50 V, 0.1 F

- capacitor, min. 50 V, 220 F

- female USB jack, for example from an USB charger

- USB charger or plastic case

- copper plate or heat sink

- cable with alligator clips (or even better 2 alligator clips)

- soldering tin

- wire


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Step 2: Prepare the casing

First open the casing of the USB Charger and cut off the wires which are connected to the male

jack. Desolder the female USB jack. You can use any box you like, but then you have to get the

female USB jack from elsewhere.

Step 3: Prepare the wires


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To remove the alligator clips from the short cables, you have to pull the protective cover off.

Now you can desolder the alligator clips.

The next step is to cut two 1m long wires and to solder one alligator clip to each one. Don't

forget to put the protective cover back on.


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If you want to use the plug of the power adaptor as shown in the last picture, just remove the

rivets with a pair of pliers. Now you can thread the free cable ends through the holes. To avoid

any traction on the solder joints make a knot in each wire as shown in the 4th picture.

Step 4: Connecting rectifier to voltage regulator


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Now we will solder up the elctronic components. The negative pole of the rectifier is connected

to the GND (middle pin) of the voltage regulator. The postive pole is soldered to the left pin of

the voltage regulator.

Help? Have a look at the pictures in this step.

Step 5: Connecting capacitors


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The capacitors' negative poles have to be connected to the middle pin (GND) of the voltage

regulator. The positive pole of the 220 F capacitor is soldered to the left pin of the L7805CV

and the postive pole of the 0.1 F capacitor is soldered up the right pin of the voltage regulator.

Step 6: Connecting the copper plate


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The backside of the L7805CV has to be soldered up the bent copper plate. To achieve the best

result we recommend to heat the copper plate with the soldering iron and spread some

soldering tin on the surface evenly. Quickly join the back side of the L7805CV to the copper

plate. The same procedure is done with the USB female jack. Depending what casing you useyou have to solder the USB female plug up the right spot.

Step 7: Connecting USB to voltage regulator


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As marked in the third picture the positive pole of the USB connector is on the right side, if you

look up front. This pin has to be soldered up the right pin of the voltage regulator with a short

piece of isolated wire. On the very left of the female USB jack is the ground pin, which has to be

connected to the middle pin of the voltage regulator with another piece of isolated wire.

Step 8: Finishing touches


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The free ends of the alligator clip cables are soldered up the free pins of the rectifier. The

polarity can be ignored in this case.

Now put everything in the box. It is possible that you have to bent the copper plate or the other

components to fit in the casing.

The Survival USB Charger is ready to use!

Step 9: Tests


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The power source you connect to the Survival USB Charger has to have a potential of at least 7

Volt and a maximal potential of 30 Volt. If the potential of the power source is under 7 Volt,

also the output voltage will be under 5 Volt.

Possible power sources can be any type of (rechargeable) batteries.

Thanks to the rectifier the power source can even be a alternating voltage source like a table

lamp. Have a look at the pictures!

I will use it with a bunch of batteries when I go camping

Have you any further possible applications? Leave a comment!

Thanks :D

survival usb charger

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