Spectrum 2-8-0 with DCC Problem

[rallygsc]

Hello Everyone 

I have a problem with a spectrum 2-8-0 with dcc,

I don't use dcc so I put the dummy plugs in, and when I run the locomotive, the headlight doesn't work.

what can I do to fix this problem?, and is this a common problem?.

I don't use dcc, I am old fashioned, and I have a lot of older locomotives, so DCC doesn't suit my needs.

any help is appreciated.

take care and thanks
George

[Pacific Northern]

Why did you take out the DCC unit?

This engine will run fine on DC, the chip senses the power supply DC or DCC and reacts accordingly.

[rogertra]

Why did you take out the DCC unit?

This engine will run fine on DC, the chip senses the power supply DC or DCC and reacts accordingly.

I guess he did that because he didn't read the instructions?

How many times do we read on this list people asking if their Spectrum DCC loco can run on DC when every Spectrum advertisement and, I presume, the instructions say that Spectrum DCC locos will also run on DC?

I don't run DCC nor do I have any locos with Spectrum nor any DCC but even I know that they run on both DC and DCC.

[TonyD]

Yeeeessssss, quit interesting how Mr. Bachmann takes the time and added expense to include the pair of 3 prong DC plugs for alterations from something us mear illiterate peasants can't understand...... could it be that 'some unknown force from beyond the universe' beckons us to remove the dcc chip? Or could it be that we the ignorant couldn't get the @#$%^&* thing to roll, then READ the directions that instructed us how to remove the chip and install the prongs..... interesting how people you meet face to face aren't so quick to be sarcastic as those on a thread..... George's locomotive now moves, it just doesn't light up.... someone gonna help him or what?

[Yampa Bob]

George:
Remove the dummy plugs, plug the decoder back in and it will work fine. You probably don't have the jumpers installed properly, and they are a poor fit anyway.

Bachmann DCC locos are DC compatible. You don't have to change a thing.
Bob

[Jim Banner]

George, I assume Bachmann includes the conversion plugs ("jumpers") for the usual reason - to make the locomotive consistable with dc locomotives that do not have decoders installed.  With very few exceptions, decoders require some "overhead" when converting from DCC to dc, mostly because of the rectifier diodes involved.  This means that for a given track voltage, the motor in the decoder equipped locomotive receives less voltage than the one in the decoderless locomotive.  This it turn means the decoder equipped locomotive is not doing its share of work when consisted with a dc only locomotive and may actually damage it.

The three legged plugs, which are used in pairs, can be fitted into the correct diagonally opposite corners of the socket and both the motor and lights will work.  But if installed in the other diagonally opposite corners, only the motor will work.  Your manual should tell you which corners are the correct ones.  If you do not have a manual, let us know and one of us will post a diagram.  If you are not running locomotives in consists, otherwise known as "double heading," "triple heading" etc. then there is no reason to replace the decoder with the plugs.

**************************************************************

It sounds like it is time once again to explain the difference between a "chip" and a "decoder."  Next time you have a dead decoder, peel off the shrink wrap (if any) and have a look at what is inside.  What you see is a printed circuit board, a piece of phenolic or epoxy reinforced with paper or fiberglass.  Unless it is a very old decoder, it will have lines of copper on both sides, connecting up resistors, capacitors, diodes and integrated circuits.  The integrated circuits (ICs) are multi-legged things, typically with black epoxy cases.  Hack one of these ICs off the board and carefully split it open.  If you are lucky, you will find the tiny square of silicon that is hidden inside.  Typically, it is the size of the head of a straight pin.  This piece of silicon is a "chip" and each decoder has several of them.  Some of them contain dozens of transistors which work together to regulate voltages or to control signals.  Others contain hundreds to thousands of transistors to make up the control logic and memory which makes the decoder do what decoders are supposed to do.  Now if you can take one of those chips, and install it in a locomotive and make it do anything then you are a better man than I am.  But if you install a package that contains ICs, resistors, capacitors, etc. on a printed circuit board, then all you have done is install a decoder, a job which thousands of us are qualified to do.



 

[Yampa Bob]

Good points Jim.

All my locos are DCC equipped, therefore I have never consisted a DC loco with one that is DCC, so I haven't experienced the difference.  The only thing I noticed was having to turn the throttle a bit farther than I would normally expect, when running on DC.  That's acceptable to me, as it reduces the "jack rabbit" effect when operating a DC loco on DC power.  In other words, it is a "softer" start, and very realistic.

At one time I had an older Bachmann DC diesel loco.  At less then 1/2 throttle, the thing was flying off the track on the corners.   I sent it to my son, he enjoys "hot rods".

I like the smoothness and broad throttle response of my DCC locos in either power mode.

Bob

[mattallen37]

George, I assume Bachmann includes the conversion plugs ("jumpers") for the usual reason - to make the locomotive consistable with dc locomotives that do not have decoders installed.  With very few exceptions, decoders require some "overhead" when converting from DCC to dc, mostly because of the rectifier diodes involved.  This means that for a given track voltage, the motor in the decoder equipped locomotive receives less voltage than the one in the decoderless locomotive.  This it turn means the decoder equipped locomotive is not doing its share of work when consisted with a dc only locomotive and may actually damage it.

rectifier diodes only decrease the voltage by .7 volts.

                                                             Matt

[Jim Banner]

rectifier diodes only decrease the voltage by .7 volts.
                                                        Matt

That would be .7 volts each.  There are always at least two in series with the motor in a DCC decoder.  Add to that about .2 volts for each of two bridge transistors and the motor connected to the tracks via a decoder receives almost 2 volts less than its mate with no series diodes and transistors.  Many (most?) of my locomotives will run on a single flashlight battery with the decoder bypassed.  So they would be working already before the motor in a decoder equipped locomotive even started receiving power.  By the time the decoder powered motor is starting to run, the decoderless motor is already receiving 3-1/5 volts which in some cases is enough to make the wheels slip.  For locomotives with higher starting voltages and lower gear ratios, this effect may not be so radical. 

[rallygsc]

I read the instructions and the instructions state that if you are not running DCC, you need to put in the dummy plug 

it is an older dcc equipped engine, not the newer one, I tried running the engine with the dcc chip at first and it ran chaotic, so I took out the the dcc chip, put in the dummy plugs and it runs as smooth as silk, but the headlight doesn't work.

I can run the newer dcc equipped diesels without a problem, I have 2 ft units and they run A-ok, it is this 2-8-0 that I am having a problem with,

I am almost tempted to buy an older tender for the loco, you know take out the old style board and put it in the new loco,

I hooked up the the engine to my union pacific 2-8-0 tender, and it worked fine, the headlight even worked.

so I know the problem is in the board of the new tender,

I don't use dcc, I don't care for it, if someone else likes it, hey that's cool, I have no use for it, I run a lot of older equipment, and I am not converting everything I have because of some new toy on the block.

I like the old fashioned DC analog setup, I am happy with it, and that is what I intend to stick with on my layout.

I did read the directions in regards to the DCC chip, and it clearly stated that I had to remove the chip in order to run it in dc mode,

Why would bachmann include dummy plugs if they didn't want you to remove the chip?.

I am not being mean, but the instructions mentioned it, so I did what it stated.

I use a Pair of Spectrum Magnum controllers for the 2 main lines, and a MRC controller for the little things like the roundhouse and the sidings.

the layout is 10 x 8, I have been working on it, off and on for the last few years,

I like the possibilities of dcc, but I do not wish to switch over to it, I have a lot of older rivarossi, lionel, and such that I really enjoy using at times.

I hope this helps
take care
George

[ta152h0]

I have a few DC locomotives and the thing that makess DCC so attractive to me is the bright headlights and the sound. However, for the headlights to show any brightness to the point it is seen, I really got to run them at full throttle ( assuming the bulb is not burned out ) I have a 2-8-2 in z scale where i can only see the lights when i turn off the lights in the room. And that is the immediate visual difference between DCC and DC. You can always jerry rig a mag light bulb to a couple of AA batteries ...........