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Ian Wigglesworth
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750 Posts
Discussion Starter · #1 ·
Hi,

Need some pointers on this as I'm now at a total loss.

I've just put a TCS-M1 decoder into my Hornby Castle Class Loco.

I just ignored the DCC socket as I didn't think this loco had one.

I also removed all chokes and capacitors.

I'm using a Bachmann EZ command control unit, the two loco's that came in the starter set work fine.

The Loco I've just converted will run fine on 90% of the track but in 1 area it goes mad.
As it enters the area it speeds up slightly at that point I have no control of the loco at all.
I turn the power off to the track, and when I switch it back on again I can't get the loco to respond at all.
I only need to move the loco to the next bit of track and full control is restored.

I've rewired that section of track and replaced the track. still no joy.
To get it to work I took another bus cable direct from the controller to feed this part of the track, everything working fine. If I connect all the track feeder cables to the bus cable using the white plastic conector block the same fault happens.
I've now got 3 bus cables all joined to the controller cable spreading out round the layout with the track feeder cables joined to these.

I'm now lost, ok it's working but I think it may be hiding another fault.
Could it be the decoder? but why only fault at certain points?
There again the two set loco's with Bachmann decoders work fine on the whole track.

I've checked all wiring for the decoder all looks fine, also tested continuity all fine.

Please anybody any suggestions or help would be great.

Ian
 

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Hi Ian,

A couple of DCC people I know have had similar problems if the layout is basically an oval. Their solution is to have a track break (both rails) at the midway point. Also if you have a power bus to fit a terminator at each end (this comprises of a resistor & cap in series, but I don't know the values offhand.)

Personally, I've never had this problem. I use Fleischmann Twin Controllers with a mixure of Lenz & ESU decoders.

Hope this may point you in the right direction.

regards
Brian

QUOTE (wiggy25 @ 30 Jul 2006, 16:54) <{POST_SNAPBACK}>Hi,

Need some pointers on this as I'm now at a total loss.

I've just put a TCS-M1 decoder into my Hornby Castle Class Loco.

I just ignored the DCC socket as I didn't think this loco had one.

I also removed all chokes and capacitors.

I'm using a Bachmann EZ command control unit, the two loco's that came in the starter set work fine.

The Loco I've just converted will run fine on 90% of the track but in 1 area it goes mad.
As it enters the area it speeds up slightly at that point I have no control of the loco at all.
I turn the power off to the track, and when I switch it back on again I can't get the loco to respond at all.
I only need to move the loco to the next bit of track and full control is restored.

I've rewired that section of track and replaced the track. still no joy.
To get it to work I took another bus cable direct from the controller to feed this part of the track, everything working fine. If I connect all the track feeder cables to the bus cable using the white plastic conector block the same fault happens.
I've now got 3 bus cables all joined to the controller cable spreading out round the layout with the track feeder cables joined to these.

I'm now lost, ok it's working but I think it may be hiding another fault.
Could it be the decoder? but why only fault at certain points?
There again the two set loco's with Bachmann decoders work fine on the whole track.

I've checked all wiring for the decoder all looks fine, also tested continuity all fine.

Please anybody any suggestions or help would be great.

Ian
 

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Ian Wigglesworth
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750 Posts
Discussion Starter · #4 ·
Thanks Brian,

I'm going to rewire the whole layout.
Going to use 2.5mm Twin & earth for the bus power line, then solder the feeder wires to this.
I'm hoping this will solve the problem.
I know I've got it running fine now but still not convinced I'm not just hiding another problem.

Maybe just me but the EZ command controller seems to get rather warm around the rotary speed controller, understandable as it's just a variable resisitor.

Will rewire it and then see how we go, if there is a short circuit the controller just beeps continuously with all lights flashing and the loco's all stop. so I can't see it being a dead short.

It is basically 2 ovals 1 inside the other with sidings off, runs all the way round the wall of a spare bedroom 2.7m down the long side 2.4m across the short side. quite alot really.

So maybe I need to completely isolate both ovals, although there are plenty of isolated fish plates on both sides of the room for the cross-over points.

Will also get the resisitors and capacitor to use as the end terminator
(found it from another thread:- 120-130ohm resistor 3Watts and 0.1Mfd Ceramic capacitor)

Thanks

Ian
 

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It sounds like you have created your own reverse loop. Usually this will occur at a point, turnout, where the track feeds will cross over. All you really have to do is provide an insulated break at the diverging routes of the turnout. Try this website for wiring up for DCC www.wiringfordcc.com. It's Allan Gartners site and it has a host of goodies to help you wire up for DCC.

Ozzie21

QUOTE (wiggy25 @ 31 Jul 2006, 08:27) <{POST_SNAPBACK}>Thanks Brian,

I'm going to rewire the whole layout.
Going to use 2.5mm Twin & earth for the bus power line, then solder the feeder wires to this.
I'm hoping this will solve the problem.
I know I've got it running fine now but still not convinced I'm not just hiding another problem.

Maybe just me but the EZ command controller seems to get rather warm around the rotary speed controller, understandable as it's just a variable resisitor.

Will rewire it and then see how we go, if there is a short circuit the controller just beeps continuously with all lights flashing and the loco's all stop. so I can't see it being a dead short.

It is basically 2 ovals 1 inside the other with sidings off, runs all the way round the wall of a spare bedroom 2.7m down the long side 2.4m across the short side. quite alot really.

So maybe I need to completely isolate both ovals, although there are plenty of isolated fish plates on both sides of the room for the cross-over points.

Will also get the resisitors and capacitor to use as the end terminator
(found it from another thread:- 120-130ohm resistor 3Watts and 0.1Mfd Ceramic capacitor)

Thanks

Ian
 

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QUOTE 50v 0.1uF capacitor and 100 ohm 3W resistor.

Is what's normally used for bus termination.
Maplins sell a snap lock connector ( you can get a sample from Halfords as well. This can easily be used with insualtion covered wire, it makes connecting your droppers to the bus simple and easy, buy red for the front wire and black for the back wire, these are known as (A) & (

wires.
With my last two layouts I havn't bothered with bus termination, and it's not been a problem. DCC users seem obsessed with making things complex for themselves. So if you want to use bus termination you have the values to use. However I don't run a complete bus ring, I just leave a gap. It should make no difference to the efficency of your bus.
With regard to your problem, it's most likely you switched polarity somewhere. For this reason the front rail known as the A rail is always wired with a red dropper. The B rail or rear rail is always wired with a black dropper. Similarly the red dropper goes to the front wire of the bus, and the black to the rear wire of the bus. If don't understand this buy DCC made easy from Amazon, it's less than 10 quid and will make things really clear for you.
 

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QUOTE (Dennis David @ 30 Jul 2006, 22:56) <{POST_SNAPBACK}>Someone else besides me uses Fleischmann's Twin-Center ...


Fraid so Dennis - IMHO it's an excellent piece of kit (it is of course an Ulhnebrook Itellibox without the Motorola protocols) & in any case my first "hands on" DCC experience was on a Fleischmann Factory Course.

I'm using four of them on a Belgian Exhibition layout that we are refurbishing.

They work out quite reasonable if you buy the starter set with the DB Class 218 & double deck coaches - even if you sell the loco/rolling stock & Profi track.
 

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Ian Wigglesworth
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750 Posts
Discussion Starter · #9 ·
QUOTE (Ozzie21 @ 31 Jul 2006, 09:47) <{POST_SNAPBACK}>It sounds like you have created your own reverse loop. Usually this will occur at a point, turnout, where the track feeds will cross over. All you really have to do is provide an insulated break at the diverging routes of the turnout. Try this website for wiring up for DCC www.wiringfordcc.com. It's Allan Gartners site and it has a host of goodies to help you wire up for DCC.

Ozzie21

I understand all of that but why would the original Bachmann loco's run fine on the same part of the track?
I've also used electro-frogs for all turnouts and the diverging ends all have insulated fish-plates joining them.
It is a strange one.
I've checked the wiring so many times as I think I'm missing something.
Everything is correct, inner rail of all parts of the track are red and outer rail all parts are black. no crossed over connections or any other fault of that sort.

Still very odd.

Thanks for the help and link

Ian
 

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QUOTE t is basically 2 ovals 1 inside the other with sidings off, runs all the way round the wall of a spare bedroom 2.7m down the long side 2.4m across the short side. quite alot really.

So maybe I need to completely isolate both ovals, although there are plenty of isolated fish plates on both sides of the room for the cross-over points.

Its probably a good ideal. I think your problem relates partly to the length of the loco passing from one circuit to another. Bachmann dont have tender pickups but Hornby to do, so it's possible you might be bridging a section and causing a short.
 

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Ian Wigglesworth
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750 Posts
Discussion Starter · #11 ·
Yipee found it!!

I thought I had removed all other loco's from the track.....I hadn't!

The 2 original set pack loco's (Bachmann) were still on one of the sidings.
When I took them off the track the Hornby loco would start to run perfectly.
If I placed each of the Bachmann loco's on the siding I would lose control of the Hornby straight away.

Just got to find out why that would be?
Checked all of the Hornby decoder wiring again all looks good and I have the "Shows you how leaflet" on decoder installation which actually shows a decoder installed on the Hornby Castle class loco.

So something in the Bachmann loco's?? I have sent 1 of these away to be repaired by Bachmann??

Any suggestions as to what I should look for?

Ian
 

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Ian Wigglesworth
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750 Posts
Discussion Starter · #13 ·
Thanks for that,

I've had a quick look in the Bachmann loco's and they seem to have soldered 3 capacitors onto the decoder circuit board, not sure which outputs they are across though.

So it could be these then?

I've taken them all out of the Hornby!

Ian
 

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Ian Wigglesworth
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750 Posts
Discussion Starter · #15 ·
Cheers Doug,

Capacitors gone....so has the fault!!!!
The Bachmann loco's that came in the digital starter set have the decoder fitted then 3 capacitors soldered across the decoder circuit board, looks like it's across the wires that go to the pick-ups.

I just snipped 1 side and left them in there, so it's easy to put back when/if I sell the starter set as a full operating kit.

Just can't belive that was causing so many problems!

You have to watch that!

Also I didn't think this Hornby was DCC ready but it is, when I saw the socket.

The problem with this type though is that the wires are soldered onto the socket go straight to the RF chokes then to the pick-ups.
The capacitor is ok as this is just across the motor brush terminals.
Point is though if you just plug the decoder in you would be a bit snookered!

Thanks again

Ian
 

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Any capacitor soldered across the motor terminals will be seen by the command station as a short. The Hornby loco won' have more han one and with the carbon choke across it it's easy to identify. Bachmann locos are a different deal as they can have up to four caps on a model. I usually remove the cap on the PCB and the chokes and wire jumpers in place of the chokes. Tha generally is all you have to do to a Bachmann steam loco but the diesels are different. I bought the Bachmann class 25 and found another three capacitors soldered across the motor terminals plus the one on the PCB. These extra caps make it slightly more difficult as you then have to pull the model to bits to get at the extra caps to remove them. I have since found extra caps on the Bachmann class 37, 40, 42 and 55 and have removed them all. This has now restored what was mediocre running models to excellent running models. It's strange this TV supression system as you never used to find it on US models prior to the introduction of DCC.

Ozzie21

QUOTE (wiggy25 @ 2 Aug 2006, 07:04) <{POST_SNAPBACK}>Cheers Doug,

Capacitors gone....so has the fault!!!!
The Bachmann loco's that came in the digital starter set have the decoder fitted then 3 capacitors soldered across the decoder circuit board, looks like it's across the wires that go to the pick-ups.

I just snipped 1 side and left them in there, so it's easy to put back when/if I sell the starter set as a full operating kit.

Just can't belive that was causing so many problems!

You have to watch that!

Also I didn't think this Hornby was DCC ready but it is, when I saw the socket.

The problem with this type though is that the wires are soldered onto the socket go straight to the RF chokes then to the pick-ups.
The capacitor is ok as this is just across the motor brush terminals.
Point is though if you just plug the decoder in you would be a bit snookered!
Thanks again

Ian
 

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Chief cook &amp; bottle washer
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I chipped mine with a Lenz Silver, not touching any cap's and it runs fine.
 

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How many locos are on the track at one time? Usually it'll manifest it's self as slow runner and may perform erratically when used with other DCC equipped locos. On a Bachmann Steam loco you generally find the caps mounted on the PCB and the problem is solved by snipping one leg of the cap or removing it altogether, my prefered option. The chokes are more of a problem and are there as part of the TV supression system. These are directly linked through the PCB to the decoder socket and should be removed
and a jumper wire wired in there place. All these items are there for DC but aren't required for DCC and they provide an extra load that reduces the volts available to the decoder. Also it can have affect on the Ac signal from the command station to the decoder that can affect on the main programming. it is best to remove these devices from the loco. On a Hornby steam loco it's nice and easy as the cap is easy to find and can be unsoldered quite quickly with care being taken to replace the wires to the same points they came off. Diesels with lighting can have a bit more junk as manufacturers can fit bulbs of various voltages ie 1.25V, 1.5V 3V and 12V. Some of these require a bit more care as two choices come to mind, fitting resistors, fitting new bulbs or LED's. These take a longer explanation.

Ozzie21

QUOTE (hoonsou @ 6 Aug 2006, 16:58) <{POST_SNAPBACK}>I chipped mine with a Lenz Silver, not touching any cap's and it runs fine.
 

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Capacitors and inductors (eg chokes and ferrites) have a frequency related resistive effect in AC circuits. When you switch to DCC, the drive to the motor is essentially AC in nature because a pulsed voltage drive is applied to the motor. This means that capacitors connected across the motor terminals will have an effect which is dependent upon the type and value of capacitor used (chosen by the loco manufacturer) and the nature of the drive signal (set by the decoder manufacturer).

This link on Wikipedia about low pass filters gives a reasonably straight forward explanation of how this works.

David
 

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Ian Wigglesworth
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750 Posts
Discussion Starter · #20 ·
I've had a bit of a nosey inside the Bachmann loco's.

These have the decoder connected to a circuit board.
Whats the extra circuit board for?

The capacitors were soldered across the decoder, which I have since snipped!

There maybe more bits and pieces on this additional PCB.

Very odd having all that inside these little loco's. It would be better to just connect the decoder to the pick-ups and motor and thats it!
This would leave room to fill it with lead to give it some weight......................now there's a thought.

Still have the loco's stop for no reason when the Hornby AND the Bachmann are all running, I think it's that extra circuit board in the Bachmann's that are causing the short failure.
If I run the Hornby on it's own I don't have any problems at all.

It's amazing that electronics in one engine can cause so much grief in another.
May have to remove this other PCB board and connect the decoder directly to the motor/pick-ups and remove everything else!!

Or maybe even better idea put these Bachmann loco's in the box and buy a brand new nice shunting engine


Ian
 
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