Battery Charger

536

11:38:42

Battery Charger circuit for mobile phones. It consists of a rectifier circuit which converts AC to DC. Then it is feeded to a zener diode which limits this voltage to around 14V. As the rectifier output is in pulses, base of the transistor connected to its line gets fired in pulses and hence flow of current through zener diode to resistors and then to capacitor takes place. 

Once the capacitor fully charged with voltage of 14V, voltage across zener and capacitor becomes equal and hence no current flows through base of transistor. As a result, transistor goes cutoff and eventually there is no further overcharging.

MODIFIED : Turn on the gate switch and get almost pure DC Output.

published 8 years ago

BillyT

8 years ago

Nice basic circuit design, but it has quite a few problems, Tidy up your circuit, then measure the voltages and currents around the circuit. Leaving the AC supply for the moment, the output of the transformers when rectified is less than 12v, so the zener circuit is never going to work properly. The output voltage dropping about 7V on a 515 (?) Ohm resistor is only going to allow about 14mA through to charge the phone, 500mA is the bare minimum amount required now days. Looking at the AC supply 230vRMS is about 326v peak. Here is a circuit to play with. http://everycircuit.com/circuit/5259753729294336

VivekChoubey

8 years ago

Thanks for the feedback @BillyT

ahmed_mahmood

8 years ago

good job ( try to make it DC ) 😊

VivekChoubey

8 years ago

@Abodi please check out the circuit now.

VivekChoubey

8 years ago

Battery charges in pulses of huge frequency.

BillyT

8 years ago

Still only 50 mA maximum

VivekChoubey

8 years ago

@BillyT true but how can I buck it up?

BillyT

8 years ago

Here is a circuit that I played with, adapt it to your needs. http://everycircuit.com/circuit/5259753729294336

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