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Project Notes

#311 Juice

Building the Boldport Juice battery replacement kit (Project #12).

Build

Notes

Juice is a battery replacement kit that uses a pretty nifty set of AA, AAA, A23 and CR2032 inserts to inject the required regulated power where a battery or two would normally be required.

Power can be supplied via the micro USB connector, or any other power supply that can be clipped or screwed on to the body of the Juice.

All the structural parts punch out from the classy PCB like a model plane kit;-) The box folds up and doubles as a “Juice box”.

Juice_pcb_front

Juice_pcb_rear

Juice_box

Juice_box_closed

Regulating the Supply

The core of the kit is the ST LDF regulator, which has a very low-dropout voltage (500 mV max. at 1 A load).

Resistor networks and the “chooser” plug allow switching between 1.5, 3V, 4.5V or an adjustable output.

Parts

Ref Description Qty
IC1 Adjustable LDO regulator, ST LDFPT-TR 1x
VR1 20KΩ trimmer, Bourns TC33X-2-203E 1x
R1,3 1KΩ resistor, Multicomp MF25 1K 2x
R2 3.3KΩ resistor, Multicomp MF25 3K3 1x
R4 5.6KΩ resistor, Multicomp MF25 5K6 1x
R5,6 1.2KΩ resistor, Multicomp MF25 1K2 2x
C1,2 2.2µF ceramic capacitor, Multicomp MCMLR50V225MY5V 2x
C3 10µF electrolytic capacitor, Multicomp MCMR35V106M4X7 1x
LED1 Orange LED, Kingbright L-9294SECK 1x
  Micro USB connector, Multicomp MC001009 1x
  6 contacts long pin header, Samtec TSW-106-22-T-S 1x
  3 contacts 2.54 mm SMD header, Samtec TSM-103-01-T-SH 1x

Juice_parts

Construction

Schematic

Build

Juice_build_front Juice_build_rear

The SS Juice with CR2032 adapter:

Juice_complete_cr2032

The SS Juice with A-series battery adapters.

Juice_complete_a_series

Note the jumper to allow multiple batteries to be replaced in series. Here’s the Juice replacing a 2xAA battery holder:

Juice_2xAA_replacement

Credits and References

About LEAP#311 BoldportPCB DesignPower
Project Source on GitHub Return to the LEAP Catalog

This page is a web-friendly rendering of my project notes shared in the LEAP GitHub repository.

LEAP is my personal collection of electronics projects, usually involving an Arduino or other microprocessor in one way or another. Some are full-blown projects, while many are trivial breadboard experiments, intended to learn and explore something interesting (IMHO!).

The projects are usually inspired by things found wild on the net, or ideas from the sources such as:

Feel free to borrow liberally, and if you spot any issues do let me know. See the individual projects for credits where due. There are even now a few projects contributed by others - send your own over in a pull request if you would also like to add to this collection.