LED power consumption?

[Birds]

Does anyone know how many watts the inverted LEDs sold by Scott's Odds-n-Ends consume?

I'm adding more O-22 switches to my layout. With factory lamps in each switch/controller combination using about 8 watts total, I am going to drain the capabilities of the small starter transformer currently powering the switches.

I could purchase a refurbished 1033, but at 60 watts I will still be short what is needed to power all the switches from one source.

Rather than purchasing large transformers basically just to power switch lights, I think a better approach would be to reduce the power consumption at the switch end.

Thanks,
Birds

[Anonymous]

The power consumption is extremely low. LED "bulbs" will pull maybe 1/5th of the incandescents they are replacing and possible much less (like 1/30th). Given the size of the "bulbs" used in our toy trains, the 1/30th is probably more likely. AKA 30 LED bulbs would draw about as much power as a single incandescent.

Looking at some of the specs, 10-1 is probably more like it.

[jefelectric]

I don't know exactly how much scott's LED draw, but a typical LED normally runs at about 20 milliamperes. At 16 volts that is less than 1/3 watt.

[Anonymous]

And the best thing is, LED's don't really get hot either, and they last a really long time compared to regular bulbs. Don't have to worry about melted bulb housings and such over time.

Chris

[Birds]

Thanks for the replies.

It took me some real digging to find info on these bulbs. What I came up with is that each LED uses about .26 watts at 13 volts. This comes out to .02 amps.

We use 14 volts to the switches. This means the LEDs will use .28 watts (.02 * 14 = .28)

Since each switch has two lamps lit at once (lamp on switch + lamp on controller) total wattage = .56 watts per switch.

Switch with LEDs = .56 watts
Switch with normal lamps = 8 watts

10 switches with normal lamps = 80 watts
10 switches with LEDs = 5.6 watts

Those old starter set transformers from the 1970s-1990s are 40-50 watts. If we figure throwing a switch takes 15 watts, and we plan on throwing two switches at once we use a total of 30 watts. This leaves 10 watts for bulbs.

10 watts / .56 = 17 switches

It looks like using LEDs in the switches should allow a 40-50 watt starter transformer to power 17 switches, and provide enough power to throw two of those switches at the same time.

If you use 15 volts to the switches then watts for the LEDs will be more.