Uwes Blog

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Many prototyping boards these days use USB Connectors as Power Source. For easy powering those devices with my DC Power Supply (or in german "Labornetzteil") i created a adaptor from 4 mm banana plugs to 4 USB Jacks.

Additional benefit is that all types of iThings can be loaded with the Adaptor. The necessary research for loading Apple devices was done by Adafruit, see their page about icharging.

The device in action:

Usage of LaborUSB

Find all the files necessary to build your own on GitHub.

I have a few boards available, if you like to build your own, contact me.



The design is really simple and consists of only 4 resistors and 8 jacks. The real work was to make the mechanical dimensions fit for easy and fast assembly.



Can be easily done by every board house.


Bill of materials


2Through-hole banana jack BlackReichelt
2Through-hole banana jack RedReichelt
1Resistor 43K 0805Distrelec
1Resistor 75K 0805Distrelec
2Resistor 51K 0805Distrelec
4USB JackDistrelec
1Laser cut Front panel 3mm thickFormulor
1Laser cut Back panel 3mm thickFormulor
4Nuts 6mm Fine Pitch Thread
4Screws M3 * 6mm
4Screws M3 * 10mm
4Hex Standoffs M3 * 12mm without Thread
4Hex Standoffs * 5mm with Thread


Solder Resistors


Prepare Front Panel


Place the banana jacks in the front panel and secure them with the additional 6mm fine thread nuts. Add one of the delivered 6mm fine thread nuts to every banana plug.

Add the 12mm standoff to the front panel with the M3 10mm screws. If you do not have 12mm standoffs, it is possible to replace the 12mm standoffs with a 10mm standoffs and a additional nuts.

Add board to front panel


Place the board on the 12 mm standoff and secure it with the 5mm standoffs.


Screw the 6mm nut up until the board is reached.


Take the remaining 6mm fine threaded nuts and secure the banana plugs on the board.

Add USB Jacks

USB Jacks

With the USB jacks from Reichelt, you need to first straighten the outer pins as seen on the left jack. Otherwise they will not fit through the front panel.


Place all 4 USB Jacks in the front panel and solder them to the board.

Add back panel

Use the 4 M3*6 screws and screw the backpanel in place.