Simple 3.7 volt battery charger with Automatic Cut Off.

Simple 3.7 volt battery charger with Automatic Cut Off.

In this video I illustrate the 3.7v charger wire connection. If the battery is fully charged to automatically close. The items needed to connect the charger are USB 5V/MJE13005 Transistor/CJ 431 011 datasheet/47 ohm resistor/two ik ohm resistors/680 ohm resistor/ and two LED bulbs.

In this video I'm showing how to make 3.7 volt battery charger circuit with auto cut off on Full Charge.

For that i used TL431 Shunt Regulator, it's actually an adjustable zener.

I used mosfet which remains on by supplying small positive voltage using 1k resistor.

And cut off voltage is set at reference pin1 of TL431 by using resistors from both positive & negative.

When voltage in circuit reaches threshold point TL431 connects negative voltage from pin2 to pin3 so positive voltage at mosfet gate pin becomes zero and mosfet turns off. 

Simple 3.7 volt battery charger with Automatic Cut Off.

In this video I illustrate the 3.7v charger wire connection. If the battery is fully charged to automatically close. The items needed to connect the charger are USB 5V/MJE13005 Transistor/CJ 431 011 datasheet/47 ohm resistor/two ik ohm resistors/680 ohm resistor/ and two LED bulbs.

In this video I'm showing how to make 3.7 volt battery charger circuit with auto cut off on Full Charge.

For that i used TL431 Shunt Regulator, it's actually an adjustable zener.

I used mosfet which remains on by supplying small positive voltage using 1k resistor.

And cut off voltage is set at reference pin1 of TL431 by using resistors from both positive & negative.

When voltage in circuit reaches threshold point TL431 connects negative voltage from pin2 to pin3 so positive voltage at mosfet gate pin becomes zero and mosfet turns off.