Dual Powered Lighting Circuit
Dual Powered Lighting Circuit
Power a lighting circuit from renewable energy or mains electricity
lighting | electric circuitIn our article
Switch from Inverter to Mains Automatically we looked at how a
lighting circuit can be powered by renewable energy, but with an automatic mains power back up. The system described was basic, but still too complicated for the average enthusiast.
Since publication, we have received many enquiries from people looking for a simple way to achieve the same goal: The ability to switch between mains power and renewably generated power for a lighting circuit whether automatically or manually.
Switching Between Mains and Renewable Energy
We came up with two solutions. The first was to have two
completely separate parallel lighting circuits - one powered by mains electricity, and the other powered directly with a
12 Volt battery (using
12V light bulbs), or via a
Power Inverter for 240 VAC light fittings.
To use
renewable energy, simply flick one of the switches connected to the renewable circuit. To use mains electricity, flick a switch connected to the mains powered circuit.
The disadvantage of this system is the
cost since the number of light fittings and switches, and the amount of cable is doubled. In addition, if this is a retro-fit solution, a lot of re-decoration will be required.
Since this solution does not require any further explanation, we will look in more detail at our second solution.
Lighting Circuit Powered via a Plug
Our second solution was to
break the connection between the mains power supply and the lighting circuit, wiring in a standard plug and socket.
When mains electricity is to be used, the lighting circuit
plug can be plugged into the new mains powered
socket. When renewable energy is to be used, the lighting circuit
plug can be plugged into the
power inverter socket (as shown in the schematic diagram below).
Most domestic lighting circuits are rated at
6 Amps - equivalent to around 1,400 Watts. The plug should be
correctly fused - for example, if just 2 Amps of lighting (around 400 Watts) are to be powered, then a 3 Amp fuse should be used.
If this technique is to be used on a
ring main (instead of a lighting circuit) a 13 Amp rated plug can be used and up to 3,000 Watts of appliances can be powered (if you have a large enough
power inverter).
nb. Thanks to recent changes to UK
building regulations, if you intend to do this work yourself you will need to have it tested and signed off by a
qualified electrician.
Article Last Modified: 08:18, 14th Nov 2007Comment on this Article
If you have any comments on this article, please email them to
neil@reuk.co.uk.
Recommended Related Articles
People who read this article also enjoyed the following articles:
Make a Simple Battery Status MonitorMonitor battery status with this easy electric circuit project - no skill required!
Article Last Modified: 12:33, 16th Mar 2007storage | electric circuitSwitch from Inverter to Mains AutomaticallyPower a circuit directly from a power inverter, but with automatic mains power back up.
Article Last Modified: 15:16, 19th Aug 2008electric circuit | storage | generalLow Voltage Battery Disconnect CircuitsFind out more about low voltage battery disconnect (LVD) circuits - used to protect batteries
Article Last Modified: 15:04, 28th May 2009electric circuit | electronics | storageSolar Charge ControllerFind out more about Solar Charge Controllers
Article Last Modified: 11:12, 29th Oct 2009solar | electronics | electric circuitLM317 High Current Voltage RegulatorFind out how to build an LM317T based high current voltage regulator
Article Last Modified: 12:29, 17th Aug 2010electric circuit | electronics | general | educationKC7783R PIR ModuleFind out more about the economical and easy to use KC7783R PIR motion sensor module
Article Last Modified: 15:16, 18th Aug 2010electronics | electric circuit | general | shoppingShunt RegulatorFind out about the uses of shunt regulators and dump load controllers in renewable energy applications
Article Last Modified: 15:13, 19th Aug 2008electronics | electric circuitPICAXE MicrocontrollersFind out about PICAXE microcontrollers and their use in renewable energy projects
Article Last Modified: 12:12, 18th Sep 2008electronics | electric circuit | educationSimple Solar Tracker ConceptMake a very simple sun tracker to maximise electricity generation from a PV solar panel
Article Last Modified: 10:37, 9th Feb 2008solar | electric circuit | generalUse a Chest Freezer as a FridgeFind out how a chest freezer can be converted to operate as an energy efficient fridge
Article Last Modified: 12:26, 30th May 2009energy efficiency | electronics | carbon