LED wiring

[Anonymous]

Elliot:

The main reason I'd use an LED over a light bulb is that the LED should last far longer than any light bulb will. I don't know how much heat a grain of wheat bulb generates, but an LED can put out about the same amount of light & much less heat. Especially in applications like switch lanterns & lighting interior rooms of structures.

Also, wiring LEDs is not that hard. While I've never done it, I've read stuff in Bruce Chubb's articles & C/MRI manual & even Daylight Don's posts on the OGR forum. All you need is a current limiting resistor (I can't remember the exact rating) connected serially with the LED & you're good to go.

Tony

[Anonymous]

Thanks for the info guys.
I am really new to this level of wiring.
How do you hook up rice and wheat grain lights?

As for the LEDS
I think I got it but I still have some more questions
Would I be able to put only two pairs together?
How would I hook them up to the resistor?
What comes after the resistor?
And finnaly how does that get hooked up to power?
Thanks again for the info.
Angelo

[lionelsoni]

LEDs are diodes, but, from an electrical point of view, not very good ones. The forward voltage ranges from about 1.5 volts for red up to 3.5 volts for white. This is the voltage across the LED when the current is flowing and the LED is lit. Most LEDs can stand a forward current of about 20 milliamperes.

In the reverse direction, no current flows as long as the reverse voltage is low enough, no more than about 5 volts. This is much less than most ordinary diodes can stand; and exceeding that value will easily destroy the LED.

You can run your chandelier on AC or DC. I will assume that you would use AC in connection with toy trains. In that case, the safest way to wire the LEDs is in pairs, with the cathode of each LED connected to the anode of the other. The cathode is the shorter lead. There is also a flat on the side of the body nearer the cathode. Of course, you don't need to know which is which--just connect unlike leads together. This way, each LED of a pair protects its mate from excess voltage.

Then wire several of these pairs in series, perhaps as many as 4 or 5 if you are using a 16-volt transformer. Put a resistor in series with the string of LED pairs to limit the current. I would start with 1000 ohms and reduce the resistance in steps until the brightness looks right.

As for the LEDs themselves, the white ones are very bluish, not realistic for a chandelier. However, there is a company, Richmond Controls, that sells LEDs that look much more like incandescent lamps: http://www.richmondcontrols.com/gldwhite.htm
You probably will want the smallest ones, T1, which are 3 millimeters in diameter.

[Roger Bielen]

Angelo:

If you have access to a copy of "Easy Electronics Projects for Toy Trains" from CTT there are methods for wiring LED's. Essentially you need to reduce the voltage, their method is to feed the 12-20VAC through a Diode (1N4001) to the LED's in parralle and then a 1000 ohm resistor, after each LED, then to ground. Using the diode you are converting the AC to half voltage DC so polarity of the LED relative to the diode is important or they won't light.

[NH_Chris]

Angelo:

There was a long article in a recent O Gauge RRing magazine that showed how to wire LEDs into switch motors that might help with the basics. The guy who wrote that article goes by the name Daylight Don, I think. You might want to google his name to find his website, which might have more information. Sorry I can't be more informative.

NH Chris

[Big_Boy_4005]

Why use LED's? Regular modeling light bulbs such as, grain of wheat or grain of rice, are much easier and will give off a better light.

[Anonymous]

Can anyone tell me how to wire LEDs ?
I want make a chandalire for one of my stations.


Thanks
Angelo