Retrofitting Low Voltage AC Garden Lights

Using LED License Plate Lights

  The object of this project was to replace the 11 watt, low voltage, incandescent lamps used in these outdoor lighting fixtures, 8 fixtures in total, with LEDs. The lamps normally used in these fixtures either burned out or became loose and would go out.

The LED License Plate Lights Used

  Although the LED assemblies used are more expensive they will pay for themselves in a few years by not having to replace or adjust the lamps and by using much less energy.

  The LED light assemblies used for this project were purchased from Princess Auto, stock number 8197618. These are designed to be replacement lights for automobile and truck license plates.

  The lights retail for $11.99 but often appear in sale flyers for half price. Similar light assemblies are available from other automotive parts retailers for varying prices.

  The packaging for the Princess Auto lights indicates that they are for 8 to 14 volts DC but the lights are actually not polarized and therefore can be used with timed or light activated, outdoor AC supplies without a rectifier.

  Two LED assemblies were used in each fixture. Each assembly has two LEDs and draws about 40 milliamps at 12 volts which gives 0.48 watts or 1 watt total per fixture.

  Each light comes with two mounting screws and a metal cover that was not used for this project.

Installed LED Lights

  For this project the LED assemblies were retrofitted to the existing fixtures to make use of the already installed supply wiring. For a new installation or a complete rewiring, the LED assemblies could be wired directly to the power supply without using the existing lamp socket.

  New aluminum foil tape was added to the floor of the fixtures to increase the reflectivity or to replace any of the original material that had deteriorated.

  Washers were used as spacers under the LED assemblies to provide clearance for the wires.

Two LED Assemblies Connected Together

  Two LED light assemblies are connected together with BLUE crimp connecters. The eyes of the connectors fit #10 terminal strip screws.

Inserting The Crimp Connectors

  The crimp connectors are inserted into the original lamp's socket with two small pieces of plastic between them to prevent short circuits. The pieces of plastic were cut from the packaging that the LED assembly came in.

  NOTE: The pieces of plastic may have to be replaced periodically as they might deteriorate when used out of doors.

Other Information

  The license plate LED assemblies could be used for many other lighting needs such as in under the layout where they could be supplied by existing low voltage power supplies or battery powered systems due to their low power consumption.

  As part of the overall project, on a four step stairway, three of the LED assemblies with their metal covers were used to replace two of the plastic light fixtures. This provided light that shone on the treads rather than across the the steps.

  The assemblies can be used by themselves with the metal cover that is supplied with each light.

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Please Read Before Using These Circuit Ideas

  The explanations for the circuits on these pages cannot hope to cover every situation on every layout. For this reason be prepared to do some experimenting to get the results you want. This is especially true of circuits such as the "Across Track Infrared Detection" circuits and any other circuit that relies on other than direct electronic inputs, such as switches.

  If you use any of these circuit ideas, ask your parts supplier for a copy of the manufacturers data sheets for any components that you have not used before. These sheets contain a wealth of data and circuit design information that no electronic or print article could approach and will save time and perhaps damage to the components themselves. These data sheets can often be found on the web site of the device manufacturers.

  Although the circuits are functional the pages are not meant to be full descriptions of each circuit but rather as guides for adapting them for use by others. If you have any questions or comments please send them to the email address on the Circuit Index page.

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18 March, 2012