Nice. Thanks, Ed.
When near my trains, I'm often in a fog. But it doesn't show up in photos.
John
AttuvianEd, Admittedly moving off topic, how did you get the foggy flavor to this great night photo? John
I bought one of the Halloween fog machines, maybe $35-40, from Amazon. It uses glycerine in it. I only use it occasionally for some photo shoots. The fog is odorless and, as far as I can tell, has no lasting effect on the layout.
There are a bunch out there. I bought mine maybe four years ago, something like this one: https://tinyurl.com/rhuduo9
IMG_3627 by Edmund, on Flickr
IMG_3599_fix by Edmund, on Flickr
Thanks for asking Ed
gmpullman IMG_3612 by Edmund, on Flickr Good Luck, Ed
IMG_3612 by Edmund, on Flickr
Good Luck, Ed
I used to have a big "decade box" with rotary dials that I could dial-in various levels of resistance then note the value that gave me the brightness I desired.
DC_test by Edmund, on Flickr
Today I use this tiny replacement, using jumpers instead of the dials:
https://tinyurl.com/yx75j787
You can still get the rotary dial type but they can run into some money.
It makes choosing a resistor based on the end brightness desired much easier.
IMG_2679 by Edmund, on Flickr
as OP my intent is for lighting PRR yellow posiiton light signals. Thank you.
wvg_caIf it makes any difference to you, differing colours will have differing percieved intensities ...just to make it interesting, lol
That is a very good point. To add to the point, if you are using tri-colour LEDs (i.e. for searchlight signals) each colour will need a different resistor to get the brightness to match. If you use just one resistor on the common lead the brightness will vary between colours. Thanks to Mel for that advice.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
If it makes any difference to you, differing colours will have differing percieved intensities ...just to make it interesting, lol
I use this array wizard to help prime my tiny brain when doing lighting projects. It gets me started and then I go to trial and error with other resistors until I get the desired brightness.
http://led.linear1.org/led.wiz
Brent
"All of the world's problems are the result of the difference between how we think and how the world works."
Too small a resistor will cause too much current to flow through a LED and quickly burn it out.
It takes an iron man to play with a toy iron horse.
Does increasing the resistance increase the light intensity or decrease it? Thank you