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Portable Battery Charger Circuit

This circuit was designed to charge Nicad battery packs in the range of 4.8 to 15.6 V from a convenient remote power source , such as automobile battery. When power is first applied to the circuit applied to the circuit , a small bias current supplied by R1 via winding L1 , starts to turn on the transistor TR1.

Portable Battery Charger Circuit Diagram

portable battery charger acircuit diagramThis forces a voltage across L2 and the positive feedback given by the coupling of L1 and L2 causes the transistor to turn hard on , applying the full supply across L2. The base drive voltage induced across L1 makes the junction the necessary base current to hold Q1 on.
Component List

R1 = 1M
R2 = 120R
R3 = 10R
R4 = 39R

C1 = 100uF 25V
C2 = 0.01uF
C3 = 4700pF
C4 = 100uF 25V

D1 = 1N4148
D2 = BYV27-5
D3 = BYV27-5

Q1 = ZTX650

L1 = 12T 36awg
L2 = 13T 36awg
L3 = 20T 30awg
L4 = 40T 30awg
Core FX3437 with gap of 0.08mm
Former DT2492

1 comment for "Portable Battery Charger Circuit"

  1. Hi,

    Portable, compact and uniquely-designed to split a 4.2charge between two ports, alternate between charging 2 Smartphones at 2.1 amp each. With a foldable prong its perfect for travel and with an universal power acceptance never be stranded or limited to charging one device from a wall socket anymore!

    This 2 USB Port 20w Travel Wall Charger is a versatile powerful and reliable charger. It is convenient, powerful, safe, easy to use, and designed to have enough power to charge Andriod or Apple 2 of any Devices Simultaneously.