Portable Switchable Power Unit for LED Panels

Thread Starter


Joined Dec 31, 2015
I a newbie to electronics projects so my ambition is ahead of my competence. Before I start stripping wires and getting the soldering iron out , I am trying to learn and plan a much as possible.

I have built 5 large LED Panels for a professional photography setup. Each panel is 12V, 9.6A. They have a small remote RF Dimmer built in and all function perfectly. Currently they operate of individual 150W, 10A PSU. I now want to remote the 5 PSUs into a single "Control Station" that is portable. I have created 5m long cables (14AWG) to the box (an old pelican case).

I currently have the 5 x 150W, 10A PSUs velcroed into the bottom of the box. I have added a single 12V colour LED light between the socket and the PSU that illuminates when the circuit is made. The PSUs are plugged into a 6 gang standard extension socket, which is then connected to a switched C14 socket on the side of the case. Thus my AC circuit functions fine.

I now want to add the option of removing the PSUs, and replacing with 12V 12A Lead Acid batteries to provide me with about an hours use in the field.

I have added cables with XT60 connectors that allow me to switch between PSU and 12V battery. I now want (in order of simplicity) to:

1.Add a master Switch
2.Add a dual Voltmeter/Ammeter to just the Battery circuit. I am confused as to how to wire this given the voltmeter should be in parallel and the ammeter in series.In the attached diagram this is shown in the red box with INCOMPLETE wiring. I need help in connecting the voltmeter/ammeter correctly. It is a
DROK® Digital Voltmeter Ammeter Voltage Current Meter DC 4.5-30V/10A 12V/24V Red LED Panel Volt Amp Tester

Battery Box 12V concept2.jpg

3. Ideally find a way to flick between Battery and Mains (i.e. leave all the wiring neatly intact), when I connect the battery. The batteries will NOT be permanently installed as at 3kg each the weight of 5 of them becomes unmanageable.

I Have the newbie challenge of interpreting and creating wiring diagrams (Any reccomensaftions for a simulator that word on a Mac gratefully received). I have put together a concept diagram, that will help explain my idea. I would then try and turn this into a circuit diagram.

Thread Starter


Joined Dec 31, 2015
The block diagram is too small for the labeled text.
Sorry - here are the main text labels:

  • The bottom Left is a 150W/10A 250VAC-12VDC converter.
  • The bottom right is the 12V 10A battery which has a 13A Fuse (orange box)
  • In the red box there is an illuminated SPST switch (rated 10a), then the Dual Voltmeter/Ammeter (5-30V 10A) with 3 wires, red, black and yellow (it has integrated shunt).
  • Above the red box is a single green round LED (12V, 0.14MA)
  • Above that is the plug/connector to the LED Panels (12V 9,6A). (The plug and the LED panels work so I am seeking help on the other components)

Thread Starter


Joined Dec 31, 2015
Here is a slightly larger version, turned L-R for easier viewing. I am particularly keen to get help in how to complete the wiring in the red box, so that I have the Voltmeter and Ammeter reading the Volts and Amps from the battery when it is attached.

Battery Box 12V concept3.jpg


Joined Aug 23, 2012
I saw the video as below and the current meter should be in series with the load(led), so you can check the new connections of the attached to be the reference.

Portable Switchable Power Unit_ScottWang.gif