Here is the array I would like to use. It draws 140MA total. That means every 4 lights draws 20MA. Can I use #38 Magnet Wire (rated 35MA) for each four light string (20MAs) as long as a heavier gauge wire is at either end? If so what gauge should the heavier wire at the ends be?
Thanks.
I wired my roundhouse with 100 LEDs in a similar fashion to what you show in your diagram. Some of the exterior lights are four SMDs in series. Most of the wire I used inside the building was 30 gauge.
The leads feeding this is 22 gauge. I didn’t do any scientific math. I used what I had on hand that I could hide among the rafters and beams.
RH_lights5 by Edmund, on Flickr
Good Luck, Ed
Looks good Ed.
I want to use these tiny LEDs with the Ngineering lampshade and use the Magnet wire to hang them down between the post in the RH. I think it will look great if I can do it.
We have a few microscopes in the house and my wife use to do lots of microsurgeries so we will see.[(-D]
That would work OK. My only comment is that’s a lot of very bright LEDs. I never run LEDs at max current, most are too bright at 50% or 10ma each. The majority of my LEDs are running about 5ma and still bright. My passenger cars average about 1ma.
Mel
My Model Railroad
http://melvineperry.blogspot.com/
Bakersfield, California
I’m beginning to realize that aging is not for wimps.
Can I use one of these upstream to adjust the brightness?
Hi Mel,
What size resistor are you using to get the draw down that low?
Thanks,
Dave
The camera exposure makes them look a lot brighter than they actually are.
I bought a few kits of those Ngineering lampshades. I thought they forgot to put them in the package! I needed the microscope just to find them. The WeHonest ones are fine for my needs:
RH_lights2 by Edmund, on Flickr
Cheers! Ed
If you’re asking me Dave I use from 3.3K to 10K at 4 volts for my passenger cars. The majority of my cars have 8 wide angle warm white LEDs to get balanced lighting. I use a 2K twenty turn pot to tweak the final light level in each car.
I placed the pot in the center of the door so that they are easy to get to and the diaphragm hides the pot and wires.
The meter is measuring the total current at 4 volts. My cars dra
Sorry Mel, senior’s moment.
Dave
That should great as a dimmer.
Mel
My Model Railroad
http://melvineperry.blogspot.com/
Bakersfield, California
I’m beginning to realize that aging is not for wimps.
Mel you do fantastic work.
I’ve not seen reference to wide angle LED’s Years ago we were looking at LED motorcycle tail lights, and while they were brighter, it was only if you were directly behind the bike.
[quote user=“RR_Mel”]
BATMAN
Can I use one of these upstream to adjust the brightness?
That should great as a dimmer.
Mel
My Model Railroad
http://melvineperry.blogspot.com/
Bakersfield, California
I have a half dozen DC to DC convertors in service on my layout and I’ve never any problems with them. I use the high current model, 8 amps continuous and up to 12 amps with a small fan. I run several voltages on my layout. 1.4 volts for the 1mm bulbs in over a 100 vehicles, about 6 amps. 5 volts for Arduinos and my control system, about 2 amps. 8.5 volts for my 12 volt Grain of Wheat bulbs in structures and street lights. 9.3 volts at about 5 amps for the GOW 12 volt bulbs that are powered by my Arduino Random lighting Controllers, about 150 GOW 12 volt bulbs total. The reason for the 9.3 volt supply is to compensate for the .7 volt drop through the high current driver so that they match the rest of my structure lighting at 8.5 volts.
The DC to DC convertors are powered from a 12 volt 30 amp switching power supply.
This is an early view of the control panel mounted Arduino card shelf with three DC to DC convertors mounted on top. Left to right is 5 volts, 8½ volts and 9.3 volts.
Thanks for the good words Henry! Here is a link to the wide angle LEDs I bought to use in my passenger cars.
I space them at about ⅞” in open areas and the center of the room in sleepers. I found using a pot to adjust the individual car lighting works out very good. I had Cataract surgery Monday and yesterday I turned down the LEDs in my heavy weight observation car.
