Hornby's R&H 48DS for analogue control.

[pauliebanger]

Simon,

 

Thank you for your kind words and endorsement.

 

I've got more on the way............

 

Best regards,

 

Paul

[sb67]

I've read the Hornby magazine article and I've got to say there's some fantastic work gone on there. One question, if operating it on DC what happens when you reduce the voltage with the controller for any length of time I.E park your loco in a siding? How long would he stay alive keep the loco sound running and would the sound go into a shut down sequence automatically?

Hope that makes sense.

 

Steve 

[Regularity]

Generally speaking, DCC sound decoders running on DC need 7V to switch the circuits on, and use the voltage above 8V for control of speed. I assume that this is still the case, and that (say) 7.5V would still need to be applied to the rails to stop the stay alive discharging itself. No idea if it would go through the shutdown/startup sequence, though.

 

Look forward to Paul elucidating us further...

[pauliebanger]

9 hours ago, sb67 said:

I've read the Hornby magazine article and I've got to say there's some fantastic work gone on there. One question, if operating it on DC what happens when you reduce the voltage with the controller for any length of time I.E park your loco in a siding? How long would he stay alive keep the loco sound running and would the sound go into a shut down sequence automatically?

Hope that makes sense.

 

Steve 

 

Steve,

 

I just spent over half an hour typing a comprehensive response to your question, but it's now lost. I'll reply later, when I've calmed down a bit.

 

The short answer is that it depends.

If you turn off power completely (all fizzles out after stay alive is exhausted) or if you reduce power so that the model is stationary but still receiving power (say 3-5V) the sound will continue playing.

 

Paul

 

[sb67]

1 hour ago, pauliebanger said:

 

Steve,

 

I just spent over half an hour typing a comprehensive response to your question, but it's now lost. I'll reply later, when I've calmed down a bit.

 

The short answer is that it depends.

If you turn off power completely (all fizzles out after stay alive is exhausted) or if you reduce power so that the model is stationary but still receiving power (say 3-5V) the sound will continue playing.

 

Paul

 

 

Thanks Paul, that's given me the jist of what I wanted to know.

 

Steve

[Captain Kernow]

On 29/10/2019 at 12:14, Regularity said:

It is inevitable that over time, most models will come with a hybrid drive, I think. The problem with that is the quality of the hybrid drive fitted as standard by an RTR manufacturer...

 

I am looking forward to being able to buy one with a small wifi receiver (if I can get one about the size of my thunmbnail, why not?) so that I can choose how to control it: via the track, directly via an app, or via a wifi-based DCC system. I can then choose how to apply the power - rails or battery - independently of that decision, too.

 

I don't understand anything of what you have just said, Simon. You must be a Time Lord yourself! 

 

[pauliebanger]

On 13/11/2019 at 18:42, sb67 said:

 

Thanks Paul, that's given me the jist of what I wanted to know.

 

Steve

 Steve,

 

Here's what I said, but expanded a little. You should beable to pick what you need from this.

 

I've tried to keep the language simple (for non-Time Lords, LOL)

 

Driving ZIMO DCC decoder equipped models on analogue (DC)

 

I am most familiar with ZIMO decoders so this advice applies specifically to this brand. Much, if not all, may equally apply to any other brand. To avoid repetition or need for technical explanations, I’ve used the terms ‘power’, ‘voltage’ and ‘current’ very loosely to mean ‘turning the control knob’. I am aware of the difference, but it has no direct relevance to the explanations below.

 

All ZIMO DCC decoders can be set to operate on DC. It is normally the default state.

 

When this condition is set and the decoder detects power without a DCC signal it automatically switches to analogue control.

 

However, it is important to remember that the decoder still controls power to the motor plus any lighting or sound which may (optionally) be fitted. It’s not as if the decoder ‘opts out’ and allows analogue power to reach the motor directly.

 

The decoder will interpret a change in voltage as an instruction, but needs a minimum to be able to operate at all. For the sake of discussion, let’s assume that will be 2.5v

 

If you increase the power from your DC controller from 0v to say 2v nothing detectable will happen.

 

If the power is increased to say 3v, the decoder will illuminate any lights which are programmed to operate when on DC.

 

If the power is increased to say 5v and a sound decoder is fitted, the sound will play. In the case of diesel sound projects, this will normally include a start-up routine, following which the Standing or Idling sound will play continuously until further voltage changes occur.

 

If the power is increased to say 7v the motor will begin to turn and the model will move. If there is a sound decoder on board, the sound project will be triggered to change the sound from Idle to another appropriate engine sound. This may also be accompanied by other automatic sounds such as a Start Whistle or Horn and a Brake release sound. (this will determined by the author of the sound project).

 

NOTE. It’s important to remember that these thresholds exist (though not necessarily the exact voltages) as they will give you a surprising degree of control given the simple nature of DC controllers.

 

Further increases in voltage up to the normal 12v DC maximum will increase the motor speed and trigger further engine sound changes as appropriate. (Usually increased revs with diesels or faster ‘chuffs’ with steam locos).

 

Since the operational range is now restricted to the portion of the control knob’s movement representing 7v-12v, movement will need to be made with extra care in order to control speed and sound.

 

Reducing power has the reverse effect. The motor will slow down and any sound will spool down or slow until the voltage is below the threshold for movement. It may well be that in order to stop the model from moving the actual voltage can be reduced to less than the 7v needed to start movement.

 

Be that as it may, there will come a point at which the motor is no longer powered, but the sound continues to play (Idling) and any lights remain illuminated.

If power is reduced further, the next threshold will be passed and so the sound will cease. In this case it will ‘fizzle out’ as there will not be sufficient power available to drive the decoder’s amplifier. (But see ‘Stay Alive’ below).

 

At this point, the model will be standing motionless and silent but with lights illuminated.

 

Reducing volts to zero or isolating the track will cause the lights to extinguish.

 

Putting all this into practice requires just that. With practice you can achieve remarkably good control of lights, sound and motion.

 

Good luck.

 

 

Stay Alive

 

Disclaimer: The use of Stay Alive technology should not be considered as a way to avoid paying close attention to track laying, track wiring, cleaning or other maintenance tasks. However, as the use of Stay Alives is not detrimental to models running under perfect conditions we would all like, but kick in automatically when used in environments which are less than ideal, some would argue that they are a useful back-up to have.

 

A commonly used method of enabling models to run without hesitation on poorly laid, cleaned or maintained track employed in DCC equipped models is to add capacitors which are capable of providing temporary on board power. These are often referred to as ‘Stay Alive’ or ‘Keep Alive’ caps. ZIMO calls them ‘Electronic Flywheels’.

 

These automatically take over when track power is lost and continue supplying power until their reserves are depleted, in which case the model will stall, or the decoder senses DCC power again in, which case the model will continue to run under full control and the Stay Alive will be recharged ready for any further power disruptions.

 

The degree of assistance which can be provided is related to the capacitance of the Stay Alive capacitor(s), although the duration can be reduced by instructing the decoder to continue running the motor for a fixed duration without power. On ZIMO that’s achieved with CV153. If the model does not reach track with a DCC signal within that limit, it will stop moving.

 

 

So with all these benefits why not use Stay Alives on analogue?

 

There are several basic hurdles in the way of this which arise from the differences between DC and DCC.

 

The fluctuating power on DC used to control speed and direction makes it difficult to arrange for the charging of these capacitors (which are polarity sensitive).

 

There’s no way that a simple DC model can determine whether a reduction in power has resulted from a power outage, dirty track or a deliberate and controlled act by the operator.

 

There may be some other technology which can overcome these issues, but I don’t know what that could be.

 

I do know, however, that DCC decoders can control the charge/discharge of Stay Alive caps, and in some cases be able to limit their duration. I also know that DCC decoders are able to run successfully on DC.

 

ZIMO decoders are the only brand that I know of which are capable of doing both of these at the same time. Due to their advanced on board software, they can distinguish between incidental loss of power and a controlled reduction for speed regulation purposes.

 

This means that ZIMO sound decoders can regulate Stay Alive caps equally as well on DC as on DCC.

 

(Other brands are either silent on the issue or like Lenz and ESU specifically point out that their Stay Alives will not operate on DC).

 

This also means that normal operation of sound on DC is enhanced with the addition of Stay Alive caps.

 

In the driving tips above, I referred to sound which would ‘fizzle out’ if the voltage was reduced below the ‘sound’ threshold. This was because the trigger to play the ‘shut down’ sequence occurred at the same point as the decoder’s amplifier was shut down due to insufficient power.

 

With a Stay Alive fitted, this is different. The decoder will be triggered to play the ‘shut down’ sequence, but as the Stay Alive will now supply power, the amplifier remains operational and will play the sequence in full (if its capacitance is sufficient). Happy days.

 

So, it is now possible to halt the model with the decoder still playing Idling sounds, after which by a further controlled reduction in volts, the engine sounds can be shut down as they would on DCC whilst still maintaining illuminated lights.

 

 

If that all sound too good to be true, you can view and hear it in action in the video I poated earlier in this thread.

 

 

Best regards,

 

Paul

Edited November 22, 2019 by pauliebanger

[Regularity]

This suggests (to me) that a controller which uses a reversing switch (without centre off) would be the best choice here.

 

28 minutes ago, pauliebanger said:

view and hear it in action in the video I poated earlier in this thread

Sounds painful!

[pauliebanger]

I left that typo in so that only those who could be bothered to read to the end would see it. LOL

 

[Ruston]

7 hours ago, pauliebanger said:

If you increase the power from your DC controller from 0v to say 2v nothing detectable will happen.

 

If the power is increased to say 3v, the decoder will illuminate any lights which are programmed to operate when on DC.

 

If the power is increased to say 5v and a sound decoder is fitted, the sound will play. In the case of diesel sound projects, this will normally include a start-up routine, following which the Standing or Idling sound will play continuously until further voltage changes occur.

 

If the power is increased to say 7v the motor will begin to turn and the model will move. If there is a sound decoder on board, the sound project will be triggered to change the sound from Idle to another appropriate engine sound. This may also be accompanied by other automatic sounds such as a Start Whistle or Horn and a Brake release sound. (this will determined by the author of the sound project).

 

NOTE. It’s important to remember that these thresholds exist (though not necessarily the exact voltages) as they will give you a surprising degree of control given the simple nature of DC controllers.

I don't understand this, Paul. If the decoder doesn't allow the motor to turn until it gets up to 7v then doesn't that mean the loco will just speed off as soon as it moves? I've tested some of my DC locos on rollers, with a voltmeter, and by the time the time the controller is turned up to give 7v they're going quite fast.

 

 

Edited November 22, 2019 by Ruston

[pauliebanger]

Dave,

 

No it will not speed off instantly. The decoder 'sees' the voltage, the motor does not. The motor is isolated from the track voltage and will only operate at the speed the decoder determines is 'correct'.  

 

The motor will then be controlled by the PWM output from the decoder. So if the decoder decides that 7v means the motor should turn, but  'very slowly' that's what it will tell the motor to do. Increases beyong the threshold will be interpreted as 'more revs', decreases as 'stop but keep sound playing and lights illuminated'.

 

As I said, the decoder does not 'stand aside' when on DC, but interprets voltage changes as instructions and then determines what should happen depending upon the sound project and CVs loaded.

 

 

(In fact, the 7v I used is just an illustration, the actual value could be different but I have not measured it.

 

The principle of the three thresholds remains the same, however, even if the actual trigger points are different).

 

Best regards,

 

Paul

 

 

[Regularity]

Think of it subtractively, Dave.

The first seven (or whatever) volts are used by the decoder,and volts above that are fed to the motor, although there is some sharing going on.

The 5 volts from 7 to 12 are used proportionately to control how many volts between 0 and 12 get sent to the motor.

That’s all a gross simplification, but hopefully gets the idea across.

[Broadway Clive]

I have found this very inspirational and tempting, but as an analogue user with a rather large loft layout that gets only intermittent use I find Relco high frequency track cleaners invaluable. I understand that they are usually fatal to DCC decoders, so is that still the case with the Zimo? My three HF cleaners are switchable but I cant guarantee I would not forget to turn them all off or ever get a link across a section boundary. One other foreseeable problem is the feedback controllers I use to keep speed steady around curves and gradients, though I could avoid those by confining Zimo use to shunting in one of the yards.

[pauliebanger]

Clive,

 

Glad to have introduced something new to you. Whether you adopt it or not is entirely your choice.

 

I've always understood HF track cleaners to be incompatible with DCC dcoders, too.

 

I can't find specific mention in the decoders' manuals so I'll find out from ZIMO and report back.

 

There is, however, a specific note that DC Feed Back controllers are OK.

 

Quote

Analog operation
All ZIMO decoders are capable of operating on conventional layouts with DC power packs, including PWM throttles, in analog DC as well as in analog AC (Märklin transformers with high voltage pulse for direction change).
To allow analog operation CV #29, Bit 2 = 1 must be set.

This is usually the case by default (CV #29 = 14, which includes Bit 2 = 1), but analog op-eration may be turned off in many sound projects (sound decoders). It is recommended to turn ana-log mode off when operating strictly on DCC!
The actual behavior during analog operation, however, is strongly influenced by the locomotive controller (power pack). Especially in conjunction with a weak transformer, it is easily possible that the track voltage collapses when the decoder (motor) starts to draw power which, in the worst case, may lead to intermittent performance.
There are some adjustment possibilities for analog operation where motor control and function outputs
are concerned; these CV’s can of course be read-out or programmed only with a DCC system or
other programming device.

 

However, since even with pure DC supply the decoder (if set up in advance for BEMF regulation) would still be supplying PWM power to the motor regulated to maintain steady speed in tight curves and on gradients, there would be no need for a PWM feedback controller for this purpose.

 

Best regards,

Paul

 

[sb67]

On 22/11/2019 at 12:57, pauliebanger said:

 Steve,

 

Here's what I said, but expanded a little. You should beable to pick what you need from this.

 

I've tried to keep the language simple (for non-Time Lords, LOL)

 

Driving ZIMO DCC decoder equipped models on analogue (DC)

 

I am most familiar with ZIMO decoders so this advice applies specifically to this brand. Much, if not all, may equally apply to any other brand. To avoid repetition or need for technical explanations, I’ve used the terms ‘power’, ‘voltage’ and ‘current’ very loosely to mean ‘turning the control knob’. I am aware of the difference, but it has no direct relevance to the explanations below.

 

All ZIMO DCC decoders can be set to operate on DC. It is normally the default state.

 

When this condition is set and the decoder detects power without a DCC signal it automatically switches to analogue control.

 

However, it is important to remember that the decoder still controls power to the motor plus any lighting or sound which may (optionally) be fitted. It’s not as if the decoder ‘opts out’ and allows analogue power to reach the motor directly.

 

The decoder will interpret a change in voltage as an instruction, but needs a minimum to be able to operate at all. For the sake of discussion, let’s assume that will be 2.5v

 

If you increase the power from your DC controller from 0v to say 2v nothing detectable will happen.

 

If the power is increased to say 3v, the decoder will illuminate any lights which are programmed to operate when on DC.

 

If the power is increased to say 5v and a sound decoder is fitted, the sound will play. In the case of diesel sound projects, this will normally include a start-up routine, following which the Standing or Idling sound will play continuously until further voltage changes occur.

 

If the power is increased to say 7v the motor will begin to turn and the model will move. If there is a sound decoder on board, the sound project will be triggered to change the sound from Idle to another appropriate engine sound. This may also be accompanied by other automatic sounds such as a Start Whistle or Horn and a Brake release sound. (this will determined by the author of the sound project).

 

NOTE. It’s important to remember that these thresholds exist (though not necessarily the exact voltages) as they will give you a surprising degree of control given the simple nature of DC controllers.

 

Further increases in voltage up to the normal 12v DC maximum will increase the motor speed and trigger further engine sound changes as appropriate. (Usually increased revs with diesels or faster ‘chuffs’ with steam locos).

 

Since the operational range is now restricted to the portion of the control knob’s movement representing 7v-12v, movement will need to be made with extra care in order to control speed and sound.

 

Reducing power has the reverse effect. The motor will slow down and any sound will spool down or slow until the voltage is below the threshold for movement. It may well be that in order to stop the model from moving the actual voltage can be reduced to less than the 7v needed to start movement.

 

Be that as it may, there will come a point at which the motor is no longer powered, but the sound continues to play (Idling) and any lights remain illuminated.

If power is reduced further, the next threshold will be passed and so the sound will cease. In this case it will ‘fizzle out’ as there will not be sufficient power available to drive the decoder’s amplifier. (But see ‘Stay Alive’ below).

 

At this point, the model will be standing motionless and silent but with lights illuminated.

 

Reducing volts to zero or isolating the track will cause the lights to extinguish.

 

Putting all this into practice requires just that. With practice you can achieve remarkably good control of lights, sound and motion.

 

Good luck.

 

 

Stay Alive

 

Disclaimer: The use of Stay Alive technology should not be considered as a way to avoid paying close attention to track laying, track wiring, cleaning or other maintenance tasks. However, as the use of Stay Alives is not detrimental to models running under perfect conditions we would all like, but kick in automatically when used in environments which are less than ideal, some would argue that they are a useful back-up to have.

 

A commonly used method of enabling models to run without hesitation on poorly laid, cleaned or maintained track employed in DCC equipped models is to add capacitors which are capable of providing temporary on board power. These are often referred to as ‘Stay Alive’ or ‘Keep Alive’ caps. ZIMO calls them ‘Electronic Flywheels’.

 

These automatically take over when track power is lost and continue supplying power until their reserves are depleted, in which case the model will stall, or the decoder senses DCC power again in, which case the model will continue to run under full control and the Stay Alive will be recharged ready for any further power disruptions.

 

The degree of assistance which can be provided is related to the capacitance of the Stay Alive capacitor(s), although the duration can be reduced by instructing the decoder to continue running the motor for a fixed duration without power. On ZIMO that’s achieved with CV153. If the model does not reach track with a DCC signal within that limit, it will stop moving.

 

 

So with all these benefits why not use Stay Alives on analogue?

 

There are several basic hurdles in the way of this which arise from the differences between DC and DCC.

 

The fluctuating power on DC used to control speed and direction makes it difficult to arrange for the charging of these capacitors (which are polarity sensitive).

 

There’s no way that a simple DC model can determine whether a reduction in power has resulted from a power outage, dirty track or a deliberate and controlled act by the operator.

 

There may be some other technology which can overcome these issues, but I don’t know what that could be.

 

I do know, however, that DCC decoders can control the charge/discharge of Stay Alive caps, and in some cases be able to limit their duration. I also know that DCC decoders are able to run successfully on DC.

 

ZIMO decoders are the only brand that I know of which are capable of doing both of these at the same time. Due to their advanced on board software, they can distinguish between incidental loss of power and a controlled reduction for speed regulation purposes.

 

This means that ZIMO sound decoders can regulate Stay Alive caps equally as well on DC as on DCC.

 

(Other brands are either silent on the issue or like Lenz and ESU specifically point out that their Stay Alives will not operate on DC).

 

This also means that normal operation of sound on DC is enhanced with the addition of Stay Alive caps.

 

In the driving tips above, I referred to sound which would ‘fizzle out’ if the voltage was reduced below the ‘sound’ threshold. This was because the trigger to play the ‘shut down’ sequence occurred at the same point as the decoder’s amplifier was shut down due to insufficient power.

 

With a Stay Alive fitted, this is different. The decoder will be triggered to play the ‘shut down’ sequence, but as the Stay Alive will now supply power, the amplifier remains operational and will play the sequence in full (if its capacitance is sufficient). Happy days.

 

So, it is now possible to halt the model with the decoder still playing Idling sounds, after which by a further controlled reduction in volts, the engine sounds can be shut down as they would on DCC whilst still maintaining illuminated lights.

 

 

If that all sound too good to be true, you can view and hear it in action in the video I poated earlier in this thread.

 

 

Best regards,

 

Paul

 

Thanks for that explanation Paul, makes sense now. 

[pauliebanger]

On 13/11/2019 at 00:23, pauliebanger said:

Simon,

 

Thank you for your kind words and endorsement.

 

I've got more on the way............

 

Best regards,

 

Paul

 

This model was operated on the Hornby Magazine 009 layout at Warley last weekend. On analogue. (sound and stay alive).

 

Here it is limbering up for it's premiere.

 

Best regards,

 

Paul

 

 

 

[009 Phil]

I've just installed a zimo and stay alive into my Hornby ruston. The stay alive keeps the sound and motor running for about 10 seconds when removed from a DCC powered track. When doing the same on some DC powered track, the motor slows to a stop almost immediately, with the sound also dropping to tickover. Is there a CV or two that I need to tweak to get identical performance on DC and DCC, as shown in the video at the start of this thread?

Thanks,

Phil

[pauliebanger]

Hi Phil,

 

No, there are no special set-up requirements. If there's a stay alive fitted correctly and the decoder is set up to run on DC it should work as shown.

 

However, I've noticed that even though the decoder will respond normally to control inputs, if you change from DCC to DC immediately, the stay alive will not work as expected since it is already charged it will retain the decoder's settings, i.e. it believes it is on DCC. This creates an anomaly when there's another form of power. It's almost as if you need the decoder to 'switch off and switch on again' which it will do automatically once the stay alive has fully discharged.

 

Try your test again when the stay alive has been fully discharged (it retains some charge long after the motor and sounds stop).

 

The same effect would probably happen if you temporarily disconnected the stay alive from the decoder, since it's the decoder's memory which needs to be cleared.

 

Give it time for the stay alive capacitors to recharge fully on DC (this will vary with the capacitance of the pack fitted) before testing and you should find you will get a similar duration.

 

Best regards,

 

Paul

[009 Phil]

Hi Paul,

Thanks for your reply and help. I'll try again and see what happens.

Best regards,

Phil

[astropsidings]

Hello,

 

All very interesting. I wonder if for DC operation the supply needs to be a smooth dc or would it work on the output of an electronic speed controller?

 

I’ve recently fitted a Zimo decoder with Simplex sound in a 20/28 Simplex, radio controlled via an RC/DCC interface, and have the same set up in a Protected Simplex. It isn’t cheap, but I would use other sound projects in other locos if I could dispense with the interface, albeit with the loss of functions.

 

A bit of video of the 20/28 working (battery powered, Zimo decoder with Paul’s sound project controlled via RC): https://youtu.be/sCCJC3Toy5c

 

Ian

 

Edited June 10, 2020 by astropsidings

[pauliebanger]

Great video, thanks for posting the link.

 

I've only tested this on pure DC so I can only vouch for that from experience, but the ZIMO manual says that PWM feedback contollers are OK too.

 

If you already own such a controller, then it would be worth a try.

 

If not, then pure DC with be fine. The main purpose (I believe, never used one) of feedback DC controllers is to provide fine regulation of the motor so that, for instance, constant speed can be maintained on tight curves, gradients and so on.

 

The Simplex sound project, like all my projects, is already set up to include the same (adjustable) BEMF regulation on DC as would be available on DCC so feedback controllers are unnecessary from this perspective.

 

Inertia and momentum settings are usually disabled in DC in my projects as I use a high momentum for sustained coasting and a brake key to provide retardation. No access to the brake key, as on DC, would make the model difficult to stop precisely.

 

However, it is straightforward to set modest values in CV3 (inertia/acceleration) and CV4 (momentum/deceleration) and it is equally simple to set the decoder to use CV3 and CV4 to provide these features when in DC mode.

 

These changes could be made before loading the sound project to a decoder, in which case they would become 'custom defaults' or if you have access to a DCC controller the existing values in these CVs may be changed 'in situ'.

 

Best regards,

 

Paul

 

[astropsidings]

Thanks, Paul. I’ll experiment.

 

Ian