I know most writings say to replace the light bulbs in Proto 1000 and Proto 2000 units for use with DCC operation, but has anyone found a suitable resistor configuration that would make these bulbs work?
Micheal
I gave up on doing it that way and now use the Digitrax DH163LO so I don’t have to replace the bulbs.
What does the Digitrax DH163LO do? Is it specially made for P2K/P1K engines with original bulbs?
'splain it to me, Lucy!![:D]
If only the NMRA, in its DCC standards, would have specified a voltage setting for the Function outputs. It would be so simple to have a CV for each output that told the decoder how much voltage to apply to the terminals. Anyone else think that this would be useful?
Yes, the voltage regulators required to do this would generate more heat, plus add complexity to the circuits on the decoder, and therefore size and expense.
They aren’t perfect, but resistors are smaller, cheaper, and simpler, at least for the time being. I retain the fond hope that future generations of decoder will start to include built-in voltage regulation somehow.
[8)]
Have you considered switching to L.E.Ds? Very bright, durable, with almost no heat.
Check out this link for info on the DH163LO.
http://www.digitrax.com/prd_mobdec_dh163l0.php
Open up and read the instructions.
It basically has a resistor/regulator on it so that you don’t have to replace the bulbs in a P2K. It replaces the light board, fits right into the 8 pin DCC socket that most P2K’s have in them. It takes the better part of 1 minute to install and get rolling again.
It was made for P2K GP7 & 9’s but I would imagine that it fits other P2k’s as well.
I think it also fits some KATO locomotives as well.
It’s not that I haven’t thought about converting to LED’s, but I have found them hard to get, plus they have an added cost, whereas resistors are pennies a piece.
Check the rating of the headlamp (ma) and then compare it to max output of the function (like 6-500ma) Place the proper value of resistor in series to drop the current to safe levels for the lamp. E=IR
O.K, I understand Michael.
It’s just that I’ve seen “warm white” L.E.Ds that were installed in Proto and Athearn HO scale locomotives and have to say WOW , WHAT A DIFFERENCE! Very bright, intense, prototypical, and the lights themselves don’t even feel warm! [8D] Looking directly at the light actually hurts my eyes! Now that’s an effect! (though not a healthy one!!)[:0][:p]
Barring any short circuits or overloads, they can last years.[;)][:D]
Also I’ve been reading DCC related info. One disadvantage that resistors offer is that they can get hot, so the recommendation was to put some distance between resistors and decoders.
Lately, L.E.Ds are becoming more and more readily available as their popularity increases.
10-4, amigos!
Thousands of LEDs can be found at:
Digikey - http://www.digikey.com/
and
Mouser - http://www.mouser.com/
You still have to have resistors for those LED’s - something has cut down the voltage! At least there is not very much current, so low wattage ones will do.
Jim Bernier
Your right Jim! [8D]
And since L.E.Ds require less “juice”, resistors will be slightly cooler. From what I’ve read the fewer amps lights draw, the better it is for overall performance, DCC and DC.
Cheers![;)][:D]
Just a Note:
The resistor is in series to limit the current flow, not the voltage to the LED. As with all semi-conductor devices, the LED is current activated. Too much and you will “pop” it.
The LED is a diode using light emiting materials and when forward biased (neg to neg, pos to pos) can drop only a small amount of voltage ( about 1.7- 2.2 volts) but can draw a high amount of current. The resistor will drop the remaining voltage and limit the total current flow to the LED.
Example: 12 volts supplied, 2 volt drop by LED = 10 volts by 470 ohm resistor.
10volts/ 470 ohms = 25.5 millamps
Series circuit means that the LED will have 25.5 ma
Main thing to remember is to always keep the LED in the design current range. This current range and LED voltage drop can be found in any supply catalog.
Hope it helps.
REX
Zimo also makes a decoder for direct connection of 5V bulbs, the MX64V5, and one for 1.5V bulbs, the MX64V1. They can be used in HO, O and smaller locos of larger scale.
They can also be updated by the user, free of charge via Internet, regardless of the DCC system used !
Anyone interested in more detail of these decoders can download the manuals here: http://www.mrsonline.net/html/manuals.html
These decoders are covered in the MX62/MX63/MX64 manual.
Regards,
Art
Zimo Agency of North America
http://www.mrsonline.net/
Rexhea,
Thanks a lot for the tip. I’ve read that one has to be especially carefull when using the lighting features when sound decoders are present as exceeding the design current range can wind up being “very unhealthy” for these decoders!
Try something in the 1/4 watt, 50 to 100 ohm range for the light bulbs. I installed a 14v Microtronics bulb and a 33 ohm resistor to dim it a bit and found I can get away with about double that without losing too much light. A 1/2 watt resistor can dissipate the heat a little better but don’t get either one too close to the plastic shell.
I see lots of answers but didn’t see any that asked what voltage you’re running your DCC on? We were originally running 17.5 V at the club but lowered it to 15 just to run the high voltage light bulbs a little cooler. At home I went all the way down to 13.5V. The resistor value will depend on that voltage plus the current draw of the light bulbs.
Different runs of Proto locomotives use different light bulbs, so you will probably have to put a meter on them to know for certain. I’m to the point of replacing light all light bulbs with ones I know the specification of anyway. Another way is to start with a high value resistor and work down to the desired brightness. Remember the brighter the light the sooner it will burn out. I run a little dull because I never want to have to replace them.
I put together a “resistor work sheet” to help the fellows in my club. Perhaps it will help you to. This is just a file not a web page so you’ll have to download.http://www.walkersquawker.net/lightbulbs.xls
I don’t know how to post a file in the form.
Texas Zepher
Nice chart. I am sure it will be handy. Thank you for making it available.
REX