Car Battary Charger Circuit

The charger charges quickly and easily on all lead-acid batteries. The charger delivers full current, decreases until the current from the battery to 150 mA. At this time, a lower voltage to complement and support more load. If the battery is fully charged, the circuit stops and lights a LED indicates that the cycle is complete.
 This very simple circuit uses a transformer, two diodes, a capacitor and an ammeter.
To charge a battery just connect the + and – terminals of the circuit at the terminals of the battery.
If the battery is not charged, shows the ammeter reading 3.1 amps.
If the battery is fully charged the ammeter reads zero or nearly zero, after which the battery must be removed from the
Charger.
The circuit is a full-wave rectifier with two diodes for rectification. The capacitor is used for smoothing.
I think the circuit works fine without the capacitor since the battery itself acts like a capacitor BIG. But if the
12V power supply circuit (such as a battery eliminator), the capacitor must be present.
Care must be taken to reverse the + and – terminals while connecting to the battery.

usb charger circuit

This change highlights series and parallel connections of the past,
allowing an increase in the number of devices that can use a Personal computer.
This simple circuit USB charger low-dropout regulator (LDO) has use IC LT1085 .
One way to use the USB power is the battery . Since many mobile devices such as MP3 players and PDAs to exchange information with computers, peripherals convenience is significant when the battery and the exchange of data takes place simultaneously on cable. The combination of USB and battery function leads to a series of “autonomous” from devices such as webcams lid, all connected to a PC or not. In many cases, it is no longer required, a clumsy adapter or wall wart. “
The battery charger from the USB can be complex or simple as you are exempt from the requirements of the USB device.
Design influence on the choice Chorus typical “cost”, “size” and “weight”.
Others following considerations:
1) the speed of a device with a battery is compatible with all functions, if a USB port
2) the time may be granted to the battery
3) power in the USB budgeting limits and
4) the need for the power supply.

Car Battery Charger

Electronic Part List

1. R1  500 Ohm 1/4 W Resistor 
2. R2  3K 1/4 W Resistor 
3. R3  1K 1/4 W Resistor 
4. R4  15 Ohm 1/4 W Resistor 
5. R5  230 Ohm 1/4 W Resistor 
6. R6  15K 1/4 W Resistor 
7. R7  0.2 Ohm 10 W Resistor 
8. C1  0.1uF 25V Ceramic Capacitor 
9. C2  1uF 25V Electrolytic Capacitor 
10. C3  1000pF 25V Ceramic Capacitor 
11. D1  1N457 Diode 
12. Q1  2N2905 PNP Transistor 
13. U1  LM350 Regulator 
14. U2  LM301A Op Amp 
15. S1  Normally Open Push Button Switch

Car Battery Charger

Part List

C1 1 6800uF 25V Electrolytic Capcitor 
T1 1 3A 15V Transformer 
BR1 1 5A 50V Bridge Rectifier 10A 50V Bridge Rectifier
S1 1 5A SPST Switch 
F1 1 4A 250V Fuse