Simple USB Battery Charger Circuit

Phones, headphones and many more things we use in our every day life.

Do they use battery?

Yes they do, they need charging.

This is small and Simple USB Battery Charger Circuit which is easy to make

It charges phone or other devices, uses few parts only, good for learning and for home uses.

So many chargers are there in market but in this article we will show how to make one simple USB charger at home.

What is a USB Battery Charger Circuit:

USB battery charger circuit is small device it takes power from USB to charge the battery.

We see this circuit in many portable things like camera, tablet, phone and more.

It charges from USB wall charger, computer or power bank.

It uses normal USB plug which are small in size, works good and easy to use.

Circuit Diagram:

Parts List:

How to Build:

• First collect all parts as per the circuit diagram.
• This circuit uses USB power to charge battery.
• Zener diode anode connects to USB positive (+) pin.
• Zener diode cathode connects to base of TIP35 transistor.
• Battery positive (+) connect to transistor collector.
• USB ground (-) connect to transistor emitter.
• Use R1 and R2 resistors to control current and voltage.

Calculate Zener Diode Voltage (Vz):

• Choose Zener diode with voltage same like battery needs this will give good charging.
• Right Vz Zener voltage is important for mobile battery.

Formulas:

Formulas for USB Battery Charger:

Vz = Vbattery + Vdrop

where:

• Vz is the Zener voltage
• Vbattery is the battery voltage
• Vdrop is the voltage loss across diode

How It Works:

• USB port gives DC power.
• Zener diode ZD controls voltage by its Vz.
• Output give near about 4.7V to charge the battery.
• To charge just connect phone or other device to circuit.

Uses and Application:

• Can charge phone and other devices with this easy USB charger.
• Use USB power no need for extra charger, this is easy and useful.

Conclusion:

This Simple USB charger circuit is small, easy and useful it charges phone and other device using USB power.

The circuit is good for learning and home uses and there is no need for big tools or hard parts.

References:

Portable USB Mobile Charger

The Basics of USB Battery Charging