Voltage for older LGB motors...?

[Zerogee]

A fairly basic question: does a DCC decoder (in general, but Massoth in particular) deliver smooth DC of varying voltage to the motor, or does it deliver full track voltage in a pulsed form? The reason I'm wondering is that I have a number of older (some VERY old) LGB locos that I'm in the process of Massoth chipping, and some of these old locos have motors that are rated at 14-18 volts or similar, rather than the 24 volts full track voltage of the LGB/MTS or Massoth systems. If the chip delivers pulsed power to the motor, am I at risk of burning out these old motors with pulsed 24 volts? Can the maximum voltage supplied to the motor be configured by altering some CV settings? Or are the older motors OK as long as I don't thrash them at full throttle?

I know some of this could probably be answered by searching through the Massoth manuals, but I find them rather impenetrable and thought I'd ask for some answers here from those of you who know the techy stuff!

Thanks in advance,

Jon.

PS: I do know that the newer Massoth Dimax units can have the maximum track supply voltage reduced or limited, is this related to the question above?

PPS: I've also just got my first Hartland (HLW) loco (well, not actually got in my hands yet, but it's on the way to me), can anyone tell me what voltage the motors in these are designed for? Anyone got specific experience of putting a Massoth LS into a Hartland loco?

 

[ntpntpntp]

Decoders generally drive the motor with PWM (pulsed). I've not come across one that drives in an analogue variable voltage fashion.

I seem to remember that there are one or two Hartland locos where the motor is a lower voltage rating (maybe only 12V) compared to the other locos they make. The mogul and possibly the 4-4-0 for example? Check on their website?

I have some Playmobil locos (supposedly 14v) that are chipped and run fine, but I will admit my system only runs at about 18V track power, not the full 24V of (say) MTS. I find that's plenty for all my various locos from little guys to large Mikados and diesels.

My old Kalamazoo 4-4-0 (ancestor of the Hartland loco) is chipped and also runs ok on my system.

I tend not to thrash my locos around the track, which probably is better for the lower voltage chipped locos in the long run.

 

[Zerogee]

Thanks, Nick, that's useful - anyone know if there is way of limiting the motor voltage on an individual loco by altering a CV on the chip, or does it automatically receive pulsed power at whatever the track voltage is? I'm going to be using a Dimax 1200Z to run the system (bought but not yet installed), so it'll be pumping out 24 volts unless I switch it down - which of course means reducing the voltage to ALL locos on the track, which is why I'm hoping there is a way of limiting it on an individual basis?

The Hartland loco, by the way, is one of their cute little Mack switchers.

Jon.

 

[ntpntpntp]

Thanks, Nick, that's useful - anyone know if there is way of limiting the motor voltage on an individual loco by altering a CV on the chip, or does it automatically receive pulsed power at whatever the track voltage is?

Must admit I assumed the minimum and maximum voltage CV's work by simply limiting the duty PWM cycle to simulate a lower average voltage, but I may be wrong. Something to research &/or measure I guess.

[edit]
hmm... most sites I've just looked at (especially Digitrax FAQ & glossary) seem to refer to these CVs as actually influencing the output voltage, so looks like I've misunderstood. I suppose it makes sense, in that you'd still want full duty cycle at full speed but just reduce the voltage.
[/edit]

The Hartland loco, by the way, is one of their cute little Mack switchers.

Ah yes, I've got one of those. Handly little chap, it pulls very well but does tend to pick up wheel crud quite rapidly. When I chipped it I fitted LED headlights, if nothing else it helps give some indication which way it intends to move off!

 

[whatlep]

A fairly basic question: does a DCC decoder (in general, but Massoth in particular) deliver smooth DC of varying voltage to the motor, or does it deliver full track voltage in a pulsed form?
(snip)

My old-fashioned voltmeter (with a moving pointer, not digital numbers!) suggests it's a smooth DC output, but if you want to be sure, ask the question on Massoth's forum. They will be back at work next Monday after the usual German extended Xmas break.
http://forum.massoth.com/

 

[Zerogee]

Thanks, Nick, that's useful - anyone know if there is way of limiting the motor voltage on an individual loco by altering a CV on the chip, or does it automatically receive pulsed power at whatever the track voltage is?

Must admit I assumed the minimum and maximum voltage CV's work by simply limiting the duty PWM cycle to simulate a lower average voltage, but I may be wrong. Something to research &/or measure I guess.

[edit]
hmm... most sites I've just looked at (especially Digitrax FAQ & glossary) seem to refer to these CVs as actually influencing the output voltage, so looks like I've misunderstood. I suppose it makes sense, in that you'd still want full duty cycle at full speed but just reduce the voltage.
[/edit]

Thanks again, Nick - do you happen to know which CV(s) they are talking about? That sounds like it would solve the problem.

The Hartland loco, by the way, is one of their cute little Mack switchers.

Ah yes, I've got one of those. Handly little chap, it pulls very well but does tend to pick up wheel crud quite rapidly. When I chipped it I fitted LED headlights, if nothing else it helps give some indication which way it intends to move off!

Heh! I don't suppose you've got any notes (or even better, pics!) of the installation in yours, have you? Do they have working lights at all, as supplied? I'm planning to put an LS in mine, with the sound file from a Pigsnout railbus as I figured that would be a nice chuggy petrol engine to suit the little Mack (I've already got the chip with the sounds on it, was going to use it in my actual railbus but have decided on the new S module for that instead, as the bus is already MTS).

Jon.

 

[D J Mason]

Hi

The decoder provide pulses at full power (ie the longer zero lasts the slower the loco runs) How old are your oldest locos ?

For the last twenty years I believe that the LGB locos where provided with 24V motors

You could just have overheating problems if you ran them continuesly at slow speed (the motor not revolving high enough to dissipate the heat generated by the full 24V)

Regards DJ

 

[Zerogee]

Hi

The decoder provide pulses at full power (ie the longer zero lasts the slower the loco runs) How old are your oldest locos ?

For the last twenty years I believe that the LGB locos where provided with 24V motors

You could just have overheating problems if you ran them continuesly at slow speed (the motor not revolving high enough to dissipate the heat generated by the full 24V)

Regards DJ

Some of the oldest are 30-35 years plus - yellow box jobs......

Looking at a VERY early LGB catalogue (1970!), the transformer/controllers of that era are only putting out 14 volts, and I think the motors are rated for 14-18 volts.

Anyone know for certain what date the change to 24 volt motors occurred?

 

[ntpntpntp]

Heh! I don't suppose you've got any notes (or even better, pics!) of the installation in yours [Mack], have you? Do they have working lights at all, as supplied?

I don't have any notes but it wasn't difficult. This is from memory...

The motor block is self-contained and unclips from the body (I think one end has a bevelled clip for your screwdriver!) You'll have to open the block and separate the motor from the pickups, adding feed wiring for the decoder in the usual way. There's a pair of wires that come out of the top of the motor block, in a brass tube which supports a cab light bulb, you'll need to disconnect the bulb.

The roof, cab sides and bonnets can be separated. I think the cab sides were screwed to the floor from underneath.

There are no other lights - the headlights are simply opaque lenses through which the cab light shines. You can feed your four new wires (pickups and motor) up through this hole in the motor block and through the body floor, discard the brass tube so that you can sit the decoder on the body floor (I think on top of a hefty weight, but again this is from memory).

So, basically I refitted the cab light to the roof with hot glue and connected it to a decoder function output, and added LED headlights with suitable resistors and connected these to the decoder.

When I get home, I'll try and sort out a photo for you.

 

[Zerogee]

Ta for the info, Nick; the little HLW Mack (used off evilBay, but looks in pristine condition) arrived this morning, runs quite nicely on the test rollers, later today I'll start taking it apart....

This is drifting a bit away from my original thread question now, to bring it back a little: when I tested the Mack just now, with an LGB 1amp analogue power pack (22 volt) the little thing was going like the clappers by the time I got it up to even half throttle..... I can't find ANYTHING on HLW's website or in their instruction leaflets about the operating voltage range for the motors, but this test would suggest that it's certainly not up to 24 volts on analogue.... The one useful thing I DID find on the HLW site was their wiring colour code for DCC connections, which suggests that at least their more recent items are semi-DCC-ready inasmuch as they have separate (and presumably accessible) power and motor connections; of course I won't know if that is the case in my Mack till I get it opened up!

Jon.

 

[dutchelm]

I added a bank of diodes to my Hartland Mack to bring the speed under control. About 5 diodes in each direction.

I have fitted an LGB decoder to the Interurban & set max speed to about 50%. I don't need DCC but it now runs at a better speed.