Mobile cellphone charger

While travelling charging of mobile battery is great problem because power supply source is not generally accessible. Here is a simple project using very common electronics components for charging mobile battery using AA cells.

Circuit descriptions of mobile cellphone charger

The main part of the circuit mobile cellphone charger is timer IC NE555, used to charge and monitor the voltage level. IC₁ get control voltage to pin 5 by zener diode ZD₁. Threshold pin 6 and trigger pin 2 is supplied with a voltage set by VR₁ and VR₂ respectively. The trigger pin 2 of IC₁ is below 1/3V_CC when discharge battery is connected to the circuit as a result flip-flop of IC₁ is switched on to take output pin 3 high. The process is reversed when battery is fully charged of charged battery is connected. Here transistor T₁ used to enhance the charging current from output pin 3 of IC₁. Adjust potentiometer VR₁ and VR₂ as per require.

LED status for different charging conditions

Load across the output	Output frequency (at pin 3)	LED₁
No battery connected	765 kHz	On
Charging battery	4.5 Hz	Blink
Fully charged battery	0	Off

PARTS LIST

Resistors (all ¼-watt, ± 5% Carbon)

R₁ = 390 Ω

R₂ = 680 Ω

R₃ = 39 Ω/1W

R₄ = 27 KΩ

R₅ = 47 KΩ

R₆ = 3.3 KΩ

R₇ = 100 Ω/1W

VR₁, VR₂ = 20 KΩ

Capacitors

C₁ = 0.001 µF (ceramic disc)

C₂ = 0.01 µF (ceramic disc)

C₃ = 4.7 µF/25V (Electrolytic )

Semiconductors

IC₁ = NE555 timer IC

T₁ = SL100 or any Medium power general purpose NPN transistor like: 2N4922 , 2N4921,2N4238, FCX1053A

ZD₁ = 5.6 V/1W

LED₁

Miscellaneous

SW₁ = On/off switch

1.5V*8 AA cells

Mobile connector

other circuit is...below..

Component of travvelling charger.

R1 = 1K
R2 = 470R
R3 = 4.7K
R4 = 270R
R5 = 27R
C1 = 100uF-25V
D1 = Green LED
D2 = 4.7V/1W Zener
B1 = 1.5Vx4 Cells
S1 = On/Off Switch
Q1 = BC548
Q2 = SK100

just_Imagine

Tuesday, 9 September 2014

Travelling cellphone charger