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Discussion Boards => General Discussion => Topic started by: jgaynor on September 03, 2010, 01:17:15 PM

Title: Help with MRC Decoder and light bulb
Post by: jgaynor on September 03, 2010, 01:17:15 PM
I have recently bought a MRC 1669 decoder and would like some help in figureing out what type and size light buld to use with it and if I need to use a resistor
thanks
Title: Re: Help with MRC Decoder and light bulb
Post by: Jim Banner on September 04, 2010, 10:49:33 AM
There are many, many different light bulbs and LEDs that you can use with decoders.  Some bulbs require resistors.  Some do not.  Almost all LEDs require resistors.  It is not so much a matter of what lamps can be used with a particular decoder as what kind of lamp will fit your application and have a voltage a current rating that the decoder can handle.

The voltage rating often depends on the scale, the maximum current rating depends on the specific decoder, and what will fit depends on the locomotive, passenger car, caboose, building etc. in which you wish to install the lamp.

Bottom line, your question cannot be answered without more information.  Sorry.

Jim
Title: Re: Help with MRC Decoder and light bulb
Post by: jgaynor on September 04, 2010, 01:15:34 PM
Jim
I just looked at the manual for the decoder and the directional lights are rated a 0.2 amp if that help any
thanks
Title: Re: Help with MRC Decoder and light bulb
Post by: Doneldon on September 04, 2010, 02:39:06 PM
jg-

That could still be okay for either conventional (incandescent) bulbs or LEDs.  The output voltage is what's needed.  The amperage says what the bulb can draw without blowing the circuit but the voltage dictates the light and whether a resistor is needed.
                                                                                                    -- D
Title: Re: Help with MRC Decoder and light bulb
Post by: richg on September 04, 2010, 04:01:05 PM
Many use a Miniatronics 1.2mm, 1.5 volt lamps.
Use a 470 om resistor.
Bulbs that operate at 12 volts tend to get quite hot and can melt plastic. headlights.

Click on the link below. This guy has a lot of useful ideas including light bulbs and LED's with decoders. Look in DCC Articles and Notes

http://www.members.optusnet.com.au/nswmn/index.htm

Rich