cellphone charger

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“ Heaven’s Light is Our Guide” Rajshahi University of Engineering and Technology Project Presentation Course Name : Electronic Shop Practice Course No: EEE-300 Welcome To Our Presentation…

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Page 1: Cellphone Charger

“ Heaven’s Light is Our Guide”Rajshahi University of Engineering and

Technology

Project Presentation

Course Name : Electronic Shop PracticeCourse No: EEE-300

Welcome To Our Presentation…

Page 2: Cellphone Charger

Developed By :• Imam Mehedi Hasan (101037)• Rakib Hossain (101039)• Md. Shakhawath Hossain (101043)

Portable Cellphone Charger

Project Supervisor:Dr. Md. Masud RanaAssistant ProfessorDepartment of EEE, RUET

Page 3: Cellphone Charger

*AbstractWhile travelling charging of mobile battery is

great problem because power supply source is not generally accessible.A fully charged battery becomes necessary especially when your distance from the nearest relay station increases.Here is a simple project using very common electronics components for charging mobile battery using AA cells & 555 timer IC which IC is an integrated circuit (chip) used in a variety of timer, pulse generation and oscillator application.Moreover by successfully completing such a project, we will understand the full process of what it is to design and manufacture an electronic device.

Page 4: Cellphone Charger

*Introduction Cellphone chargers are nothing but AC to DC

converters. They take an input of 220 volt AC and give an output voltage around 5Volt DC. Basically, the charger is a current-limited voltage source. Generally, cellphone battery packs require 3.6-6V DC and 180- 200mA current for charging. Current of 100mA is sufficient for charging the cellphone battery at a slow rate.

Phones have rechargeable batteries inside which need to be charged with a DC voltage (slightly higher than the battery voltage). Simple phone chargers provide this DC voltage. Ours is the one kind of this. It is a universal mobile charger so we can connect any mobile connector. For example. If we want to build a charger for Nokia then we have to install a Nokia pin or if we want to connect a Sony Ericsson mobile we can install Sony charger pins at the output.

Page 5: Cellphone Charger

*Apparatus

Apparatus ValuesR1 390 ΩR2 680 ΩR3 39 Ω/1WR4 27 KΩR5 47 KΩR6 3.3 KΩR7 100 Ω/1WVR1, VR2 20 KΩ

Apparatus ValuesC1 0.001 µFC2 0.01 µFC3 4.7 µF/25V

Capacitors

Resistors

Page 6: Cellphone Charger

*Apparatus Apparatus Values

IC1 NE555 timer ICT1 SL100ZD1 5.6 V/1WSW1 On/Off SwitchBattery 12 VLED1

Page 7: Cellphone Charger

*Circuit Diagram

Page 8: Cellphone Charger

*555 Timer IC (Pin diagram)

Page 9: Cellphone Charger

◊ Timer IC NE555 is used to charge and monitor the voltage level in the battery.

◊ Control voltage pin 5 of IC1 is provided with a reference voltage of 5.6V by zener diode ZD1.

◊ Threshold pin 6 is supplied with a voltage set by VR1 and trigger pin 2 is supplied with a voltage set by VR2.

◊ When the discharged cellphone battery is connected to the circuit, the voltage given to trigger pin 2 of IC1 is below 1/3Vcc and hence the flip-flop in the IC is switched on to take output pin 3 high.

◊ When the battery is fully charged, the output terminal voltage increases the voltage at pin 2 of IC1 above the trigger point threshold.

◊ This switches off the flip-flop and the output goes low to terminate the charging process.

◊ Threshold pin 6 of IC1 is referenced at 2/3Vcc set by VR1. Transistor T1 is used to enhance the charging current.

◊ Value of R3 is critical in providing the required current for charging. With the given value of 39-ohm the charging current is around 180 mA.

*Working Principle

Page 10: Cellphone Charger

*Experimental Setup

Page 11: Cellphone Charger

*ResultAt lab, the circuit was tested with a Nokia make

cellphone battery rated at 3.7V, 320 mAH. The charging current measured was about 200 mA. The status of LED1 is shown in the table.

Page 12: Cellphone Charger

LED StatusLoad across the

OutputLED1

No Battery Connected On

Charging Battery Blink

Fully Charged Battery Off

Page 13: Cellphone Charger

*Features and Benefits

Charger holds enough power to recharge your mobile devices.

Compatible with any model of cell/smart phones.Charge cell/smart phone for up to 12 hours of

additional talk time.Color LED indicates charging status.Automatic turn off charging when charging is

complete.Mobile can be charged anywhere where power is

not available.12V battery is rechargeable.

Page 14: Cellphone Charger

Thanks!

End Of Presentation