Charge-a-Phone on NiMH

with the Elektor USB Power Pack

The goal of this project is to allow standard AA size rechargeable batteries, like NiMH, to effectively charge portable devices like smartphones and tablets through the USB connector. By using a separate battery holder, you’re able to exchange discharged batteries with fresh ones without having to charge first, or open the enclosure. That’s a big plus if your phone, tablet or e-gizmo is in serious need of charging and you’re in the middle of nowhere.

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Materials

120631-PCB.pdf

Gerber file

CAM/CAD data for the PCB referred to in this article is available as a Gerber file. Elektor GREEN and GOLD members can exclusively download these files for free as part of their membership. Gerber files allow a PCB to be produced on an appropriate device available locally, or through an online PCB manufacturing service.

Elektor recommends the Elektor PCB Service service from its business partner Eurocircuits or AISLER as the best services for its own prototypes and volume production.

The use of our Gerber files is provided under a modified Creative Commons license. Creative Commons offers authors, scientists, educators and other creatives the freedom to handle their copyright in a more free way without losing their ownership.

PCB

Download Gerber file: 120631-1.zip

Components

The BOM (Bill of Materials) is the technically exhaustive listing of parts and other hardware items used to produce the working and tested prototype of any Elektor Labs project. The BOM file contains deeper information than the Component List published for the same project in Elektor Magazine. If required the BOM gets updated directly by our lab engineers. As a reader, you can download the list here.
Want to learn more about our BOM list? Read the BOM list article for extra information.

Download the BOM list

Component list

COMPONENT LIST
Resistors
(0805, 125mW)
R1,R3 = 1.8MOhm 1%
R2 = 330kOhm 1%
R4,R5 = 200kOhm 1%
R6 = 47kOhm, 1%
R7 = 2.7kOhm, 5%
R8 = 10kOhm, 5%
R9 = 1kOhm, 5%
R10 = 18kOhm, 5%
R11 = 1.5kOhm, 5%
R12 = 1MOhm, 5%
Capacitors
C1,C6 = 10µF 10V 20%, X5R, 0805 (Taiyo Yuden LMK212 BJ106MG-T)
C2,C7 = 100nF 50V 10%, X7R, 0805
C3 = 10pF, 50V, ±0.5pF, C0G/NP0, 0805
C4 = 2.2µF 6.3V, 10%, X5R, 0805
C5 = 220µF 6.3V, 20%, SMD, Ir=2.8A (Nichicon PCS0J221MCL1GS)
C8,C9 = 120µF, 6.3V, 20 %, SMD, Ir=2.8A (Nichicon PCS0J121MCL9GS)
C10 = 1nF, 50V, 10%, X7R, 0805
Inductors
L1 = 10µH, 5A, 0.025Ohm, 20% (Würth Electronics 74477110)
L2 = ferrite bead, 70Ohm @ 100MHz, 3.5A, 0.022 Ohm, 0603 (Murata BLM18KG700TN1D)
Semiconductors
D1,D3 = LED, red, 3mm through hole (low current)
D2 = 5.1V zener diode, 0.5W (SOD123), Diodes Inc. MMSZ5231B-7-F
IC1 = TPS61030PWPG4 (Texas Instruments)
IC2 = TPS2511DGN (Texas Instruments)
T1,T3 = DMS3016SSS-13 (SO8)
T2 = BC847B

Miscellaneous
K1 = USB connector, type A, receptacle, PCB mount, SMD
K2 = 2-way vertical screw header, 0.15'' (3.81mm) pitch (Phoenix Contact MKDS 1/2-3.81)
S1 = Slide switch, SPDT, right angle, 100mA (C&K Components OS102011MA1QN1)
Enclosure, 66.22 x 67.22 x 28.00 mm (Hammond Manufacturing 1593KBK)
PC board screws (#4 x 1/4" self-tapping, 6.4mm, Hammond Manufacturing 1593ATS50)
BT1 = 3 AA battery holder, snap contact (Keystone 2475) + battery clip (BUD Industries HH3449)
3 NiMH batteries
PCB # 120631-1 v3.0