Individual motor starting voltage adjustment.

[Neil Robinson]

On DCC this is programmable into the chip, but for unchipped analogue locos this is of use in several applications.
These include delaying the loco start until there is some power to the lights or smoke unit or sufficient power to get standing sounds from a sound unit. It may also be used to get differing locos to run at similar speeds on the same controller settings.
From GSM

Edit, diagrams added as they may no longer be available via the link.
Non conducting diodes shown in outline.
A B and C are possible positions for constant voltage lighting, A is non directional, B and C are directional.

 

[Alpineandy]

Neil,

always useful posts, have you got the one for 5v voltage regulator as well ?

Thanks
Andy

 

[Tony Walsham]

Neil Robinson - 26/10/2009 7:59 PM

On DCC this is programmable into the chip, but for unchipped analogue locos this is of use in several applications.
These include delaying the loco start until there is some power to the lights or smoke unit or sufficient power to get standing sounds from a sound unit. It may also be used to get differing locos to run at similar speeds on the same controller settings.
From GSM

1. How does one go about programming start speed in an analogue loco that is not chipped?

2. Assuming the loco was chipped, how does one go about programming start speed if there is only analogue DC present on the track?

 

[Neil Robinson]

Alpineandy - 27/10/2009 10:38 PM

Neil,

always useful posts, have you got the one for 5v voltage regulator as well ?

Thanks
Andy

Yes it's the "Low voltage circuits for lights, smoke etc." thread in the "Locomotives Trams & Rolling Stock -> Locomotives & Trams section."

 

[Neil Robinson]

Tony Walsham - 27/10/2009 11:18 PM
1. How does one go about programming start speed in an analogue loco that is not chipped?

2. Assuming the loco was chipped, how does one go about programming start speed if there is only analogue DC present on the track?

Hi Tony,
1. add diodes to the motor circuit as per diagram.

2. Get a dealer or mate to alter the CVs. I think it's CV2

 

[don9GLC]

<p>

Neil Robinson - 27/10/2009 11:38 PM

Tony Walsham - 27/10/2009 11:18 PM 2. Assuming the loco was chipped, how does one go about programming start speed if there is only analogue DC present on the track?

Hi Tony, 2. Get a dealer or mate to alter the CVs. I think it's CV2

</p><p>From my reading of the Massoth XLS manual (version 2.2) CV2 is effective only on DCC. It actually varies the voltage applied to the motor corresponding to speed step 1. If set too low it does not ensure that the loco will actually start. But if set too high will give the Ferrari type acceleration that seems to be common at least in the smaller scales
</p><p>To quote the Massoth manual</p><p>'The start voltage (CV2) defines the driving voltage of speed step1. The smaller the voltage the slower the locomotive drives. If the PI-Load Control is &ldquo;off&rdquo; and the locomotive does not move in speed step 1, the start voltage should be increased.' </p><p> </p><p>On test, I have found that my Massoth chipped locos require about 10 Volts DC (LGB) to 12 Volts DC (BRAWA) on analog before they start to move which easily allows lights and sound to be functional before any movement. Voltage measured at the controller, not the wheels, so I'm not sure how much Volt drop there was along the rusty track, which also is R1 circle (hence more load on motor, but locos running 'light'). My analog controller is a cheap and rather insensitive device and the Voltage seems to fall (slightly) once the loco is moving.</p><p>In my experience there is no need to program a higher start Voltage for a chipped loco on analog. The electronics are more sensitive than the motor. I'm fairly sure that on a straight test track even a single unloaded analog loco had its lights on before it started to move, even without diodes. Two final reservations, my locos are relatively large RhB models (Ge2/4, Ge 4/4 and G4/5) and might just need a bit more power than some smaller ones and also they have voltage regulated lighting - i.e. connected to the decoder. So my experience may not hold true for everyone.
</p><p>Don
</p>

 

[Neil Robinson]

Ah, thanks Don. With hindsight probably the statement in my original post should just have said that the diode circuits are pointless for chipped locos.
I have been lead to believe that some analogue running characteristics of chipped locos can be adjusted and some find this advantageous.

 

[Tony Walsham]

So I guess the answers to my two questions are just as I thought:

1. You cannot. Adding diodes is not programming.

2. You cannot. Taking it to someone who has DCC means it is not able to be programmed on DC.

Unlike a QSI PnP DCC sound decoder, which can be run on DC and programmed on DC.

 

[Neil Robinson]

Tony Walsham - 28/10/2009 5:42 AM
Taking it to someone who has DCC means it is not able to be programmed on DC.
Unlike a QSI PnP DCC sound decoder, which can be run on DC and programmed on DC.

I hope the ESU product is similar to the QSI in some respects as I have purchased, but not yet installed, an ESU chip on the basis of the following exchange with ESU's U.K. agent.

Me:-Hi,
I'm considering using an ESU locsound unit as purely a sound unit in an analogue LGB loco.
Am I correct in assuming that I may program the motor starting voltage to be relatively high (I have a computer-decoder interface unit) in order to get the loco standing sounds by applying a track voltage just under the motor start voltage?
Also is there any way of triggering effects such as the bell and whistle with an external device such as a magnet and reed switch?

Reply:- Hi Neil,
Sorry for the late reply. The decoder can provide both sound and traction. This is the only way of synchronizing sound with the motion. the decoder requires 7v to wake up the sound, so setting the motor voltage to say 8v would be good. Aux outputs 5 / 6 can be re configured as inputs for sound to be triggered from a reed switch.

 

[don9GLC]

<p>

Tony Walsham - 28/10/2009 5:42 AM So I guess the answers to my two questions are just as I thought: 1. You cannot. Adding diodes is not programming.

</p><p> If there is no chip, what is there to program? However, if you need a higher DC track voltage to energize lights or sound units before a loco starts to move, adding diodes is one way you could do this.
</p><p> </p><p>

Tony Walsham - 28/10/2009 5:42 AM 2. You cannot. Taking it to someone who has DCC means it is not able to be programmed on DC. Unlike a QSI PnP DCC sound decoder, which can be run on DC and programmed on DC.

</p><p>I'm not familiar with the QSI decoders but a quick look at their website seems to indicate that they can only be programed in DC using their Quantum Engineer which seems to be a DCC controller but without several DCC features, for example loco selection or multiple loco control. Alternatively you can program them using separate devices, as you can with 'normal' DCC. In theory you can run DCC with DC rather than AC track power, (just like the Quantum Engineer appears to do) so your answer is not technically correct. Unless you are programing on main, (when you have to stop the loco anyway) DCC does not energize the track power, either AC or DC, when setting CVs. The output is a series of command pulses, a data stream rather than AC or DC. I suspect you have to stop a QSI chipped loco to alter CVs so technically you are not programing on DC.
</p><p> </p><p>I'm not sure why anyone would want to retain analog control when operating chipped locos, but Rule 8 applies. Its your railway, do whatever you want and enjoy! </p><p> </p><p>Don
</p>

 

[Tony Walsham]

There are many Large Scale people who would like the quality of the QSI sound but do not want DCC period.
That is not a criticism of DCC. It is just the way it is.

The QSI sound can be run on DC and the only proviso for successful operation is the DC voltage must be filtered linear and not PWM.
You can control the Whistle/Horn and bell by simply flipping the direction switch.
No provision is made for having trackside triggers. Although I understand that may change in the not too distant future.
Although the Quantum Engineer does make programming easier you can actually program a QSI sound decoder on DC. I know. I have done it. I have also controlled the loco and sound with on board battery R/C and programmed the QSI with the R/C to achieve the optimum performance.

I have no experience of ESU Loksound, but if they are half as good as the QSI they will likely be pretty user friendly.

 

[don9GLC]

<p>

Tony Walsham - 28/10/2009 1:15 PM There are many Large Scale people who would like the quality of the QSI sound but do not want DCC period. That is not a criticism of DCC. It is just the way it is.

</p><p> </p><p>Quite right Tony, Rule 8 is paramount. Its all about having fun and doing what you enjoy. </p><p>Incidentally technically speaking, the alternative to DCC is analog, not DC. Some very early German toy trains used AC analog! You are in fact using a simple form of DCC when you flip the direction switch to produce a sound on your DC loco, but what's in a name!
</p><p>Keep having fun</p><p> </p><p>Don
</p>

 

[Tony Walsham]

As far as I know QSI is the only DCC sound decoder that can be manually controlled when running with non DCC track power without the addition of any extra components other than a reversing switch.

Given that the DCC signal is actually bi-polar DC and not AC, then yes, flipping the direction switch could be considered a crude form of DCC.

 

[madmanx]

Not being an expert on electronics, but is it not feasible to insert a suitable resistor in series with the motor to reduce track voltage across the motor, whilst maintaining full track voltage for sound, lights etc. My Accucraft loco starts to move at about 2.5V and protoype max speed reached at only 7V, but the sound card and lights need minimum 8V to function properly.

 

[Neil Robinson]

madmanx - 1/11/2009 12:45 PM
Not being an expert on electronics, but is it not feasible to insert a suitable resistor in series with the motor to reduce track voltage across the motor, whilst maintaining full track voltage for sound, lights etc. My Accucraft loco starts to move at about 2.5V and protoype max speed reached at only 7V, but the sound card and lights need minimum 8V to function properly.

Indeed it is feasible, the choice is yours.
Personally I choose to use diodes as their forward voltage drop is, unlike that of a resistor, constant and independent of the current flowing through it.

 

[Doug]

Neil - just a quick question on diodes vs resistors to drop the voltage to the motor.

Does a diode dissipate the same amount of heat as a resistor ? (both in the same case scenario ie dropping 0.7v)

 

[Neil Robinson]

Doug - 1/11/2009 4:29 PM

Neil - just a quick question on diodes vs resistors to drop the voltage to the motor.

Does a diode dissipate the same amount of heat as a resistor ? (both in the same case scenario ie dropping 0.7v)

Quick answer; yes, the energy lost has to be dissipated somehow.

 

[palmerston]

<p>For all analog locos with DCC-interface (no dekoder) Massoth sells a liitle device thats let the light burn <strong>before </strong>the loc sets off! DC-motorregelung fur LGB-loks</p><p><a href="http://www.massoth.de/de/produkte/8410101.de.php">http://www.massoth.de/de/produkte/8410101.de.php</a></p><p> </p><p> </p>

 

[tramcar trev]

Of course for us tramoholics banks of resistors are de rigour as I have plenty of underfloor space I may install a few of these, just for effect.....

 

[Rhinochugger]

MMmm, I think I must be a bit simple.

I thought analogue was two wires; one directional switch; and a speed control....................................

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