L.E.D’s (Part one)

L.E.D’s

Miniature lighting technology has changed & progressed massively over the last couple of decades. With the advent of affordable L.E.D’s (Light emitting diode) & L.E.D technology coming on in leaps & bounds, L.E.D’s are now found all over the place, from street lighting, vehicle lights, torches, TV’s, high tech devices & much more. L.E.D Manufacturing costs have fallen considerably making them more widely used from industrial to domestic to now becoming very popular in hobby uses.

Grain of wheat bulbs was the medium of choice for lighting when I first started in the hobby many years ago, but with L.E.D’s being cool running, long lasting & cheap to run the grain of wheat bulb is becoming less popular. L.E.D’s when originally released were available in a limited range of colours & sizes. Now the L.E.D’s are available in many different sizes & a huge range of colours to choose from including multi coloured colour changing types, it couldn’t be a better time to start fitting them to your layout.

With the advent of S.M.D version (Surface mount diode) of the L.E.D, opens up even more options for the modeller. The S.M.D’s are now available in many different sizes including sizes under 1mm !!

So what kind of uses can L.E.D’s & S.M.D’s be put to on your layout? Here’s a few examples:

• Locomotive lighting
• Rear tail lamps
• Street & yard lighting
• Wall mounted lighting
• Interior lighting on your model buildings
• Interior lighting on coaches
• Road vehicle lighting
• Emergency vehicle flashing light beacons
• Colour light signals
• Over head lighting for displaying a layout
• Flickering fire effect

Plus many more uses not listed here.

Some facts about L.E.D’s

• L.E.D’s are very reliable with a very low failure rate if used properly. If not used properly & with care an L.E.D will fail instantly.
• L.E.D brightness isn’t linear in proportion to current consumption set by the combination of voltage & resistance. To make an L.E.D. dimmer you’ll need to use a resistor. For example: To dim an L.E.D on a 12v supply use a 1000 ohm resistor for example. But if wanting to produce a much dimmer light then look at using a resistor of 5000 ohms or more.
• Each L.E.D type/colour has a different type of efficiency. Using two L.E.D’s on the same circuit you must allow for fitting a resistor to each individual L.E.D.
• For model railway use, a safe minimum resistor value to use is 1000 ohms. This assumes an average current consumption of 10mA for coloured L.E.D’s & 20mA on white L.E.D’s. Thus giving us safe knowledge & confidence to work on DC power between 6V & 18V
• The Diode part of the L.E.D only works when power flows the correct direction from anode to cathode. If the power flows the opposite way then an L.E.D will stop & not work.
• L.E.D’s are semiconductors which come from the same family as transistors & microchips. How they are protected & powered has a bearing on their life span & performance.

Using our lighting kits

Here at Scalemodelscenery.co.uk we always recommend that you MUST use the supplied resistors with our kits if using a power supply larger than 3 volts. ALWAYS use one resistor per light when using a power supply larger than 3 volts. Fail to do so will result in blowing the L.E.D & it failing instantly!! We recommend using a separate transformer 12 to 16 volt supply to power our lighting kits.