Yellow Lights in DCC On Board GE 44 Ton Switcher

[hotrainlover]

Dear Board,
Has anyone changed the lights in one of these locos?  I want to just swap out the YELLOW LEDS for WHITE ones.  I do not know if there is a specific LED needed.  I would think I could just clip off the old and solder on new ones.  Anyone know if the PCB would support that?

[richg]

The resistors should be on the PC board. Take a look. Very easy to do.
My 44 ton with sound is the version with light bulbs so not an issue for me.

Rich

[Br 98.75]

i took out the pc board an put us a 9 pin wiring harness and a dh123 because the one that was in it ran poor.

[electrical whiz kid]

A rule of thumb is not to overload whatever you are installing.  Since LEDs have very little resistance in a forward" position, then whatever resistor you had with the existing LED  should be ok.  DO CHECK YOUR SPECS THOUGH.  I usually use about a 700ohm resistor, 1/4 watt.  I like the golden LEDs as they seem to give a realistic glow.  The only one I haven't done it to is my Bachmann 4-8-2 mountain-There is just something about that blue glow on that locomotive that grabs me!  Sort of like a blonde in a red dress.
Rich C. 

[hotrainlover]

Thanks for the replies.  Will try a direct replacement...  Or a Redhead in black fishnet.......  Grrrrrr   

[richg]

The OP might be interested in these measurements. I have worked in electronics since the 1950's and started working with LED's in 1972. Never had to use math thought I can if necessary.

LED Resistor Values

Measured with 12.2 VDC supply using 20 ma max current LED's. Values will vary a ittle depending on actual DC supply value. My decoders put out about that level of voltage.

Resistor      Current
1000 ohm    9.0ma

750 ohm     12.45ma

680 ohm     13.12ma

510 ohm     16.25ma

Some of the super bright LED's to day can require at least double the resistance. I keep a supply of resistors on hand, plus a 2.5 k pot and a 5 k pot for testing.
Four multimeter's
If you want to work at the component level, have the proper stuff. Eliminates guess work.

Rich

[Br 98.75]

the redhead may be a good replacement but a tcs micro led should work great. plus you gave me an idea to tell which way is forward on my little rust bucket

[utdave]

here's a simple way to figure your resistance for leds
Most LEDS  are 3 volt 10ma or RGB are about 20ma   knowing these are important . To find the current limiting resistor first you need a power source   lets say  13 volts dc can be anything over 3 volts  forward voltage .  OK  you need to take 3 volts  from 13 volts which gives you 10 volts  and 10ma =.01a     take your voltage  10 volts  and divide by .01a  and you should get 1000 ohms or 1k ohms minimum

example 2      now you are hooking to a 24 volt dc source         21 volts divided by .01a and you should have  2100 ohms . 
OK this is the minimum size resister you will need always add  more resistance  to dim and save the life  of the LED.

i found this on a led website  this is so easy to use  play with it  and have fun 

[richg]

Everyone remember, if you happen to get some super bright LED's everything will change. Calculation will probably not help.
I belong to a number of DCC groups and every so often read where some have to at least double the resistance. There you need a variety of resistors and maybe a potentiometer to get the correct brightness and pick out the closest standard value from your junk box.

Rich

[richg]

If you like experimenting for colour. many use Tamiya Clear orange X-26 acrylic paint.

Rich