The widespread availability of USB mobile charger ports in laptops and computers has simplified the process of charging your mobile devices. This circuit is designed to provide a controlled voltage of 4.7 volts for charging your phone. USB outlets typically supply 5 volts of DC power and 100 milliamps of current, which is adequate for a gentle mobile phone charge. This circuit can also serve as a Mobile Phone Travel Charger Circuit, allowing you to charge your phone on the go.
Charging is accomplished using the mobile device’s USB connector, a convenient power source for phone charging. Most contemporary computers feature two to four USB ports. USB, short for Universal Serial Bus, represents one of the latest advancements in data transfer between computers and external devices. While USB ports provide 5 volts of power at pin number 1, with pin number 4 at 0V, it is essential to consider this voltage differential. However, the USB port can supply up to 100 milliamps of electricity, which is more than sufficient for this modest application.
USB Mobile Charger Circuit Diagram:
Components used in this Circuit:
- Zener diode-4.7V/. 5W
- Resistor: Flow of current in the circuit is being controlled by the resistor.
- Capacitor: It is mainly used to store the charges. It is of two types polarized and non-polarized, electrolytic capacitor is an example of polarized while ceramic and paper is non polarized.
- Transistor: It used to enlarge the signal strength or to open or close the circuit.
- Zener Diode: When the voltage achieves the breakdown point it starts working but in the reverse bias state.
- Diode: It is a having two terminal named as anode and cathode. It allows the current to flow only in the forward direction while stopping the flow of current in the backward direction.
USB Mobile Charger Circuit Description:
Many mobile phone batteries operate at a voltage of 3.6 volts with capacities ranging from 1000 to 1300mAh. These batteries are typically comprised of three lithium cells, each rated at 1.2 volts. For fast mobile phone charging, a voltage of 4.5 volts and a current in the range of 300-500 mA are required.
However, it’s worth noting that charging your battery slowly can enhance its overall efficiency. The circuit outlined below maintains a regulated voltage of 4.7 volts and delivers an ample current for gradual mobile phone charging. Voltage regulation is accomplished through the transistor T1, while the output voltage is controlled by the Zener diode ZD, and polarity protection is offered by D1.
The front portion of the circuit should be connected to a USB plug, with pin 1 linked to the red wire for easy polarity identification, and pin 4 attached to the black wire. To charge your cell phone, connect the circuit’s output to the appropriate charger pin. Once all circuit components are assembled, insert the USB plug into the socket and use a multimeter to measure the circuit’s output. If the output is correct and the polarity is correctly connected, you can connect your phone to it.
These days, you can easily find multi-chargers in the market, so consider purchasing one. This allows you to charge your mobile phone conveniently while on the go, as many people carry laptops or notepads with them when traveling on trains or buses.
Note: Extreme care is needed to be taken that polarity are connected in the right manner, if it attached in wrong style it will damage the battery of your mobile phone.
To construct a USB mobile charger, you’ll need a USB cable that includes at least one male socket with approximately 5cm of exposed wiring and exterior insulation at the “uncovered” end. Typically, USB cables consist of four wires, which are red, black, green, and white (along with their respective insulation).
Since the green and white wires are dedicated to data transmission and are not needed for this purpose, they can be carefully clipped, ensuring that the wires within their insulation remain protected. The negative wire is typically colored black, while the positive wire is red. It’s important to note that the voltage provided by the battery is 5V, and the device connected to the USB port should not draw more than 500mA of current.
When attaching the power line to the USB plug, be sure to verify the correct polarity.