Roco/Fleischmann Multimaus power 18v transformer

[portsladepete]

Hi, I have a multimaus and use it on a small ish layout.

 

I occasionally and intermittently have locos stopping and starting immediately,regardless of their position on the track without any evidence of a short.

 

The track is cleaned to within a inch of its life,same goes for loco wheels.

 

The supplied transformer 18v 36va (new type).

 

Would an 18v 4amp transformer be of any benefit,if the supplied transformer can only supply 2 amps?

 

Would really appreciate any advice.

 

Thanks Pete

[Phil S]

Without some more information about the number of locos on your layout, and the proportion with sound, if any, and the number  of coaches with lights ...I'd hesitate to suggest a specific cause.

Are you ALSO using the track power to operate point motors  - or do you use eg the Lenz LS150 which uses a 16Vac power supply (from an old fashioned mains transformer), and only uses the dcc signal for the information content. 

I only have 18Vdc 4A SMPS power supplies providing my track power, and I use 4 of these for my loft layout...  feeding through PS-X intelligwent breakers which ALSO inhibit the surge currents occuring after a short circuit or at Power On. As DutchMaster mentions, sound-fitted locos with their large capacitor storage, or some coach lighting with large capacitors, can cause start up problems...

 

However, the imference from your description is that these stop/start problems occur 'randomly'??

This suggests a variation in the (quality or amplitude) of the dcc sigfnal reaching the loco: check any analogue interference suppression capacitors have been removed from the track feeds. Check that there is sufficient 'conduction' from all parts of the track back to the controller, by applying the 'coin test: Place a metal coin across the track - anyhere and everywhere - it should ALWAYS cause the Multimaus and Amplifier to indicate a Short Circuit and cut the track power .... if this does not iccur, it may be that you have poor contacts through fishplates etc resulting in a voltage drop whenever/wherever power is being taken from the track. ... the solution is to improve the track bus feeds with more frequent connections to the track and thicker wire.

 

If it is simply 'too much stock' for the 2A supply - you must be running about 6-8 modern efficient locos, or perhaps 1 old one with an X04 8-) ... changing to a 4A supply (3.2-3.5A limit from the Amplifier) will improve the situation ... but recheck with the coin test to ensure that the newer, higher short circuit current is enough to trip the Amplifier.

[portsladepete]

Thanks for your inputs,to clarify some of the questions raised

 

I have bus wires supplying power approximately every 2 feet of track,

 

There are no point motors fitted,I am only using the latest transformer adapter,

 

All my locos are modern,I only have 2 or at most 3 active at any one time,the rest are "parked"

 

I have two Hornby TTS locos,they are the worse culprits for momentary stopping,all the rest of my locos are non sound,the majority fitted with Hattons own decoders.

 

Up until recently when a loco hesitated,nothing showed on the multimaus screen,after a weeks holiday away,a Bachmann class 37,(fitted with Bachmann decoder) hesitated,the loco lights went off,and the multimaus screen showed the start up scrolling as though it had been switched off.

 

Since then I have cleaned the track again before operating each session,and have had no stopping,but this fault is so random I can never be sure I have identified anything specific.

I have read Phil S's posts on the multimaus and you seem to be a font of all multimaus knowledge,hence my question regarding a higher amperage transformer.

 

Hope you can offer some advice,I will try the coin test in the meantime.

 

Thanks again Pete

[Suzie]

It depends which power supply you have. Early ones have a high power transformer (very heavy) that might be producing a rather high track voltage, and later ones have a wal wart type switch mode power supply that produces the correct voltage but probably not enough current if you have a heavy load.

 

The answer probably for both scenarios is to get a new 18V 4A switchmode power supply to replace what was supplied.

 

The 'amplifier' supplied with the Multimaus is a 4A one and you will only need to add an extra booster if you are drawing more than 4A.

[portsladepete]

The adaptor/transformer supplied gives 36va which equates to 2 amps I think.

 

There are universal ones on ebay for about £10 that give 18v  90watts which is 4 amps I think.

 

Would these be ok,just don't want to risk the multimaus.

 

Thanks again everyone

[portsladepete]

The adaptor/transformer supplied gives 36va which equates to 2 amps I think.

 

There are universal ones on ebay for about £10 that give 18v  90watts which is 4 amps I think.

 

Would these be ok,just don't want to risk the multimaus.

 

Thanks again everyone

[Phil S]

Sorry Phil, but I have to disagree about that transformer. The MultiMaus system is designed for the PSU it has and the booster part can't deliver any more power then the 2A limit. To illustrate this analogy (s'cuse the pun ): if you have a 1/4" water tap, it doesn't change one iota in how much water comes out of it whether the water mains is 1/2" or 12 inches wide.

Phil: Sorry, but you are incorrect in this case: The 10764 Amplifier (which is also the SAME as the Booster, internally) is rated as 3.2A output. It was originally supplied with a 50VA transformer 10752, which can no longer be supplied, except as a spare part, once old stock was used up, as a result of EC regulations on energy saving and efficiency: hence replacement by SMPS supplies.

Note that although the original amplifier was marked as ac input, it is now marked as ac/dc (or simply 'unmarked'); because it has always had a full wave rectifier inside it, with sufficent rating for the full power via dc.

 

Therefore an 18Vdc Power Supply of 3.5-4A rating is perfectly satisfactory to use with it:  It ensures the Amplifier will NOT be 'starved' of power which would or could prevent the over current protection from working correctly.  (Note that the range of acceptable voltages is lower if the input is ac, becasue it is the rms and not peak value which is quoted)

 

If you are in doubt; I recommend you use a Rampmeter to monitor your output voltage and current ... as I do on each of mine.

 

As with Hornby, Roco now supply a lower-capacity SMPS with the Multimaus/Amplifier as a starte pack - it is cheaper to make and distribute. However a higher rating version is available (4A).

Any 2-terminal SMPS with 18Vdc regulated output, able to provide 3.5-4A , with a suitable plug can be used - NOTE THAT EXCLUDES certain Dell power supplies which uses a 3rd sense terminal !!

 

Similarly, I use a 10A 22V supply for my Massoth Dimax 800 (selectable to 8A max),

[Phil S]

Thanks for your inputs,to clarify some of the questions raised

 

I have bus wires supplying power approximately every 2 feet of track,

 

There are no point motors fitted,I am only using the latest transformer adapter,

 

All my locos are modern,I only have 2 or at most 3 active at any one time,the rest are "parked"

 

I have two Hornby TTS locos,they are the worse culprits for momentary stopping,all the rest of my locos are non sound,the majority fitted with Hattons own decoders.

 

Up until recently when a loco hesitated,nothing showed on the multimaus screen,after a weeks holiday away,a Bachmann class 37,(fitted with Bachmann decoder) hesitated,the loco lights went off,and the multimaus screen showed the start up scrolling as though it had been switched off.

 

Since then I have cleaned the track again before operating each session,and have had no stopping,but this fault is so random I can never be sure I have identified anything specific.

I have read Phil S's posts on the multimaus and you seem to be a font of all multimaus knowledge,hence my question regarding a higher amperage transformer.

 

Hope you can offer some advice,I will try the coin test in the meantime.

 

Thanks again Pete

This might be the best clue so far !!! - Check that the clips on the RG plugs at each end of the Multimaus connecting lead are not broken  or bent back such that they do not engage properly in the socket .... if the lead pulls out slighty, the power will be lost and the multimaus (WHICH IS WHERE the PROCESSOR is located, and which generates the Master DCC signal, when plugged via the Master Socket) has to restart itself.  Alternatively, the lead itself may have become damaged.  Try another one.

    The MASTER uses all 6 wires of the cable - the SLAVES only use 4 .... 2 For Power, and 2 for Expressnet ... The extra 2 FROM the MASTER are the DCC signal TO the Amplifier

 

(I have a couple of leads in which the clip has broken - embarassing a a show if used on the master, as it stops everything 8-(. 

On the small ZTC 'shaped' handset, I once had, the RG plug was poorly retained internally, and kept coming loose - a better grommet was required as a strain relief)

 

SOUND ! You now advise that 2 TTS locos are on the layout - even if not moving, they are consuming power, and probably don;t have 'stay alive' circuitry ... the other stationary locos will also be taking some power, but not much.  I have not checked to see at what track voltage the TTS decoders 'drop out'.

 

I only use the 2A supply on my 'test board' for programing, or a static display track (for lighting etc), and so I am only used to the full capability of the 50VA transformer originally (!Caution: excessive voltage when no trains running!! - I now use these transformers ONLY for 16Vac accessory control).

 

I also have Rampmeters on each of my Power Disitricts - showing that with 18Vdc in (from SMPS supplies) a track voltage of 16Vdcc andtypical currents from 0.25 to 1.5A where I have many coaches with lights parked!  I can follow a loco around the layout by watching the current level change in each disitrict as it goes round.

Each District/sub-District also has its own PSX intelligent circuit breaker to overcome problems experienced when I first started having sound locos and increasing coach lighting (I had to disconnect the capacitrors inside the early Hornby Pullmans!)

 

(Also note, that despite the apparent paranoia or excessive concern some have about track voltage being above 12V !! - Prior to electronics, Triang Hornby Controllers were rated as 14-16Vdc ouptut, H&M '12Vdc' outputs could be as high as 20V! (easily)  with a very unsmoothed full wave rectified waveform, and WHEN A DECODER IS FITTED a Motor never sees the FULL TRACK VOLTAGE !! .... It can get close to it ONLY if you then drive it at FULL SPEED ... which many of those who might be 'concerned' would never approach because it is above the walking pace of their branchline 8-)

 

Since decoders became high-frequency switching, and not 50Hz like Zero-1/early DCC days, this has not been a problem. The other 'voltage limit' NMRA advice was the concern about an UNFITTED loco being used (very inefficiently) on dcc and advising against having a track voltage higher than 16V for this ...now solved by many controllers not allowing 'Loco Zero'

However, unregulated Coach Lighting, which was designed to be adequate for analogue track voltaqge/speeds, CAN result in too bright and too hot a coach lighting experience !!!

manufacturers (in europe if not elsewhere) changed to 16V bulbs many yeatrs ago ... then to LEDs often with regulators. Note that '12Vdc LED strips will take double their current at 14Vdc .. so I add diosed and resistors to dim them

 

A 16Vdcc (regulated) is much better than a transformer-load-varying output of say 14-22V .... 'drop out' is less likely to occur at distant parts of the layout. Lighting is more constant.

 

TESTS which should be made on the track:

 

1/ The COIN TEST - to ensure that the wiring is adequate so that a track short (eg with a coin) ANYWHERE on the layout trips the Protection of the Amplifier/Central Unit  .... too much resistance in the path would allow the current to flow with a reduced voltage, giving NO protection.  The HIGHER the Central UNit CURRENT RATING the better the wiring needs to be !!!

 

2/ THE LOAD TEST: CHeck the TRACK VOLTAGE at the 'most distant part' of the layout when a SOUND or other heavy-consuming loco is moving in the area ... the track voltage must not drop below 7V, or some decoders will restart themselves ... preferably remain much higher 8-)

 

18V SMPS 3.5/4A Power Supplies are readily available from under 20GBP to 50+ if you buy from Maplin when not on offer.  An SMPS thends to 'run cool' espacially when nothing much is being taken from it .... unlike a transformer ...  so also check your 2A supply is not running hot, or in direct sunlight.

 

Whilst I would normally recommend PSX's.... recent threads have suggested they have changed software, incorporating a faster response time which can interfere with older relay-based Auto Reversers ..  However,  PSX -AR is also available, as are Auto Reversers which DO NOT have a Short-Circuit-Triggers, but use a Short SENSE TRACK instead.

[portsladepete]

Thanks Phil,for your detailed reply.

 

I understand most of it,although I was competent with dc, the apparently simple dcc leaves me a bit unsure what the dickens is going on.

 

I have now tried isolating all other locos when running the tts locos,(separately)it does seem to cut down on the momentary stops,and a strange fault on the diesel tts,where it sits playing the brake release noise but not moving is also less. This fault can be overcome by pressing a function (horn,thrash etc) or switching the sound off,and was thought to be a decoder issue.

The unit was replaced by Hornby eventually but the glitch is still there,

 

However it seems that isolating  the other locos reduces this a lot.

 

I have checked the throttle end of the cable,that seems ok,will check the other end shortly.

 

Can you confirm that the coin test is perfectly safe?

 

I bought the multimaus initially because it seemed far superior to the start set controllers at a fantastic price,but when comparing it to other sub £200 controller reviews,to my mind it is a far more user friendly device,and does everything I need remarkably well,

 

I have ordered an 18v 90w transformer off ebay for £9,seems a cheap way to check the possibility of "starvation"

 

Thanks

[Phil S]

 

Can you confirm that the coin test is perfectly safe?

Phil: I can confirm that if the Coin Test Works - then your layour is correctly protected ! - if Not, I guarantee that it is not ! (Remedy if it fails to trip is to use thicker wiring ... )

 

If it does not trip immediately, then remove the coin.   I once had a fault inside a Fleischmann Point, with its internal switch ... and a current of 3.5A was flowing... unstopped, because my ZTC511 I was using at the time had a 5A limit ... but thankfully it had a current display.. so I saw the large current being taken with no train moving, and looked for the fault with an ohmmeter...

 

By ohms law, for the continuous current allowed  of 3.2A @ 16Vtrack ... V=IR       so  16 = 3.2 x the wiring resistance including locos etc ....    (Layout) Resistance  16 / 3.2  = 5 ohms

So, for the automatic protection to work as intended, the layout resistance must be LESS than 5 ohms or you will NEVER get enough current during a short circuit to operate the trip.

 

I have ordered an 18v 90w transformer off ebay for £9,seems a cheap way to check the possibility of "starvation"

Phil: I hope you mean 'Switched Mode Power Supply' with 18Vdc output,  and not a 'transformer' !!!     

 

I refrained from 'recommending' on on ebay because there are some 'poor' suppliers offering mislabelled products .... I once had a 'Dell' Laptop power supply which was probably the lower rating, but labelled as the higher 90W rating model my laptop required ... it ran hot, and failed after a few months.

 

A (mains) transformer is frequently misdescribed in model railway forums: - an inductive device (ie [2] windings coupled by [a laminated core for mains frequencies] for changing ac voltages from one value to another.  Its inefficiency comes from having to store all of the energy required in 1/100 second as a magnetic field in the laminations, and then back to electrical energy in the secondary wnding. It has no inherant regulation of the output voltage, which therefore tends to vary with the load ... DROPPING to the QUOTED value at FULL LOAD. (and much higher voltage with minimal current)

 

FYI

There is a much smaller transformer used inside a Switched-Mode Power Supply ... here the input (ac or dc, 110 or 230V for example) has been CHOPPED at high frequency my high-power transistors, to form a high frequency ac signal which is sent to the Primary of the (small) transformer ... again converted to magnetic energy and back again into the seconday, beforer being rectified and regulated to produce the 18Vdc output required.  

 

The switching of the power transistors is controlled, so that it is proportional to the POWER being used by the LOAD (layout)  -so they are hardly on when minimal current is required, and fully on when full load is requested.   Because the frequency sent into the transformer is so much higher, it is probably a ferrite core, and only has to store the energy used in perhaps 1/10,000th of a second... which allows t to be made smaller and more efficient, which , in turn, makes it smaller and more efficient ......

 

The regulation circuitry will also include overload protection, so that it will work upto the full load, with the correct voltage, but once over a certain limit, will cut out instantly.   The 10764 also has its own protective cutout - but based on 3.2A presumably.

 

Obviously I too like the Multimaus - having rather a lot of them !  We use them for 00, H0, 009 and G Scale  indoors. -

Although we have also gone down the MultiCentralePro route (now a dead-end) giving us the Wireless Pro version.  I now have a Z21 but have not yet used it for a layout

rgds

phil

[Tim V]

Is it an EU import Multimaus adapter, with the two round pin plug?

[portsladepete]

I think I am using the wrong term,the "transformer" on ebay is for a laptop,so I have assumed it is a suitable supply.

 

My PSU ?? is indeed a 2 pin european 36va one,not the earlier version with its  reported associated high voltage problems.

 

I bought my multimaus  from Europe for around £60,as stated it has been reliable and user friendly purchase.

 

My layout is only about 10ft long so I cannot see any real benefit in having a booster besides the cost implication.

 

Having read seemingly reams of threads regarding DCC, to me, it seems the amount of problems people have are not necessarily reduced by the purchase of more expensive control systems.

 

 I realise that the variety of layouts/locos and people's ability makes it difficult to pin down the reason for more unusual problems.

 

I just hope that my laptop supply purchased works as described,and doesn't melt my mouse!!

[Tim V]

In that case check the security of the two mains pin in the adapter, what is happening is intermittent contact to the mains, causing your multimaus to reboot. Happened to me a lot!

 

You can even create the problem by waggling the mains adapter.

 

Try replacing the two pin adapter with a better one.

[portsladepete]

Thanks Tim,

 

 

makes sense,I will ensure it is fully home,I am going to try the laptop supply,at least that will have a normal 3 pin plug!

[portsladepete]

Just received my multi voltage laptop power supply,everything works,thanks to everyone who gave advised.

 

The 18v setting gives 18.8 volts and the 16v gives 16.8 volts,I have left it on the lower setting for now,as I wanted your advice whether the 18.8 volts is ok.

 

The multimaus gave 17.8 volts.

 

These voltages are all without load.

 

Thanks in advance

 

Pete

[Phil S]

The only specific item I have found to 'not work' due to too low a voltage, has been PROGRAMMING the Rocoline DIGITAL point motor - operation was okay once programmed.

From my earlier trials with voltages, I don't think either setting will cause you a problem .... the choice might then be more related to the physical size of tour layout, and the length of cabling runs, to ensure that under maximum load, the voltage does not drop noticeably .. such that sound decoders have problems when at this furthest extent.

I use RRampmeter's to monitor my voltage and current, as well.

(Note that the 'higher' voltage will be better for the overload protection, as being more likely to be able to generate enough 'short circuit current' around the track - but if the overload protection still works at the 'lower' voltage, there is no problem )

It was reducing the voltage down nearer 12V that showed (on a scope)  the output waveform suffering - as if the internal switching was spending too much time in the linear region

 

Have you already noticed how cool the SMPS runs (although, it was, of course, a smaller  SMPS you were using before ... which I assume was the 17.8V mentioned above ??)

Unlike the old-fashioned 50Hz transformer (230Vac:16Vac 50VA) which runs warm even when no trains are running.

[portsladepete]

Thanks Phil,

 

yes the power supply does run cool,I have been trying  the TTS locos,the steam one stopped momentarily twice on the lower voltage so upped it to the 18 volt setting and no

 

stopping,neither time did the multimaus reset itself.

 

I did try to replicate the fault by wiggling the two pin adapter on the original power supply,but could not get it to cut out

 

My layout is only about 10 feet by 5 feet, the running lines are are two continuous ovals.

 

Hopefully this is the end of my problems.

 

On the whole I have found moving to dcc a positive decision,but  at times I have felt like tearing my hair out !!

[Mark Forrest]

I've been running my Multimaus with two throttles (one wired, one wireless) with an 18v 1.1 Amp power supply from Gaugemaster for a while now. Never had any issues, although it's only used on a small layout and rarely used for more than one loco at a time.

[Phil S]

Mark Forest  Yesterday, 22:31

I've been running my Multimaus with two throttles (one wired, one wireless) with an 18v 1.1 Amp power supply from Gaugemaster for a while now. Never had any issues, although it's only used on a small layout and rarely used for more than one loco at a time.

 

Phil: Out of interest; have you tested the overload protection - does the cutout occur at the Roco Amplifier - or at your Gaugemaster Power Supply? (is it SMPS?- you didn't specify - I assume it is)

If the Gaugemaster has to do the protection, then you will presumably be losing power to all your handsets... with power starvation during a short,  and watching them restart????***

With a 3.5-4A supply, the supply is 'maintained' with the Amplifier operating the protective cutout ... there is no interruption of handsets, and the Red light on the Amplifier indicates the protection occuring which is then released from a handset.

 

*** or there may be more 'intelligence' in the Amplifier's detection circuitry than I give it credit for 8-)

 

(Note that SMPS have their own inbuilt protection - and if they have an LED visible - this might flash during ITS OWN overload protection ... usually from a damaged cable to the Amplfier/load)

[Mark Forrest]

The Gaugemaster is just their basic "wall wart" type, can't seem to find it on their website right now.

It doesn't cut out when there is a short, the throttles remain on and indicate the short on their display and (i think, from memory) the red LED on the amplifier comes on as it should.