# A Challenge for our Smart Electronics Guys



## Jerry McColgan (Feb 8, 2008)

I can tell a diode from a resistor but I cannot follow current electronic circuits. 

The Revolution puts out PWC and my Soundtraxx Sierra diesel sound units do not work right with PWC. OK, I know Aristo is coming out with a PWC to linear adapter for their Trackside but I am old and impatient and I figure why wait if some sharp fellow MLSer can solve my problem for me. 

Soundtraxx Sierra used to make an RC Adapter Board that did three things. 
1. it lowered the voltage to a level that the sound board could work with 
2. it provided constant voltage to keep the lights bright and the sound system on 
3. it converted DCC (and PWC) to linear DC 

Here is their circuit: 

http://1stclass.mylargescale.com/jerrymccolgan/Aristo-Craft/Soundtraxx19a.jpg 

If I wanted and needed the full circuit all that stuff would be necessary but in my case I am going to be putting the Sierra sound system into some non-Aristo locos that do not have plug and play interfaces and that have (3 wire LED) lighting systems that I just don't want to mess with. 

That means that I can skip step 1 (I don't need to lower the voltage because I want to feed the Sierra board direct from the Revolution Motor Output and I will be controlling the voltage rather than feeding the board full track voltage). 

This also means that I can skip step 2 (I am willing to settle for the lights and sound system not coming on until the motor output voltage - or for the sound system the back up battery - provides the voltage they need). 

I probably don't need the bridge rectifier because I may want to use the DC voltage polarity to automatically activate the forward, reverse and stop horn signals. 

Basically all I want is a circuit like I have for DCC that works to make a LGB analog sound car work under DCC (unfortunately it does not work with PWC). 

http://1stclass.mylargescale.com/jerrymccolgan/Circuit.JPG 

http://1stclass.mylargescale.com/jerrymccolgan/LGB Sound Cars/LGB Sound with AD322.jpg 

Can anyone tell me how to make a quick, easy and cheap filter (with or without following the Sierra circuit) to get a Sierra diesel board to work with PWC? 

Thanks, 

Jerry


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## George Schreyer (Jan 16, 2009)

There is no quick and easy way, sorry, I've tried all the suggestions offered in various forums, several hacks that I have dreamed up myself and the Soundtraxx docs (in all their revisions) and in every case, SOMETHING doesn't work correctly. 

The suggested circuit will work with steam systems, but not very well with diesels. The problem there is that the engine has to get moving fairly fast before the sound starts to ramp up. Since it discards the Sierra battery, it is sensitive to track power interruptions, even with the 2000 uF cap. 

The only method that I have found that WORKS with ALL motor controllers is the one on my web site. However, it is quite a bit more complicated than even this circuit but it has worked each and every time using the older TE receivers and at least three kinds of DCC decoder. I have not tested it with a Revo, but since the Revo uses an H bridge like virtually all DCC decoders, it should work with the Revo too. 

http://www.girr.org/girr/tips/tips6/sierra_tips.html


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## Stan Cedarleaf (Jan 2, 2008)

George... thanks for that input. 

The only thing I've found that works with the REVOLUTION and Sierra diesel modules is the Sierra adapter board. I, too have tried a number of "other" things, none of which work. 

Yes, with steam modules it's not a problem. They work fine with the REVOLUTION without the adapter board.


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## Greg Elmassian (Jan 3, 2008)

Maybe I am missing something here... is the circuit that Jerry showed in his link the "Sierra adaptor board" that Stan refers to? 

I don't see the requisite pulse integration circuit that I see in George's site. 

All the Sierra docs I see are just the circuit I see that Jerry posted, a regulated DC supply and 2 optoisolators. 

Don't see how that does near the job that George's circuit does. 

Regards, Greg


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## Jerry McColgan (Feb 8, 2008)

Posted By George Schreyer on 10 Jun 2010 02:57 PM 
There is no quick and easy way, sorry, I've tried all the suggestions offered in various forums, several hacks that I have dreamed up myself and the Soundtraxx docs (in all their revisions) and in every case, SOMETHING doesn't work correctly. 

The suggested circuit will work with steam systems, but not very well with diesels. The problem there is that the engine has to get moving fairly fast before the sound starts to ramp up. Since it discards the Sierra battery, it is sensitive to track power interruptions, even with the 2000 uF cap. 

The only method that I have found that WORKS with ALL motor controllers is the one on my web site. However, it is quite a bit more complicated than even this circuit but it has worked each and every time using the older TE receivers and at least three kinds of DCC decoder. I have not tested it with a Revo, but since the Revo uses an H bridge like virtually all DCC decoders, it should work with the Revo too. 

http://www.girr.org/girr/tips/tips6/sierra_tips.html 

Well, my post went to never never land.

Anyway what I was saying was that my experience mirror's George's. The sound does not start until after the loco is moving fairly fast.

Jerry


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## Jerry McColgan (Feb 8, 2008)

Posted By Greg Elmassian on 10 Jun 2010 05:03 PM 
Maybe I am missing something here... is the circuit that Jerry showed in his link the "Sierra adapter board" that Stan refers to? 

I don't see the requisite pulse integration circuit that I see in George's site. 

All the Sierra docs I see are just the circuit I see that Jerry posted, a regulated DC supply and 2 optoisolators. 

Don't see how that does near the job that George's circuit does. 

Regards, Greg 

Hi Greg,

The schematic I posted originally on this topic is from the RC Adapter Kit back page. These schematics are from the build-your-own instructions:

http://1stclass.mylargescale.com/je...maticT.jpg
http://1stclass.mylargescale.com/je...maticB.jpg

I don't know if this will answer your questions or not. From what I can see the circuit seems to be the same as the first one I posted.

I would be confident that George's circuit would be better. I just would not understand why Sierra would put out a circuit that did not work. There must be more to the story than what I am seeing. 

*The instructions never actually mention PWC.* 

Regards,

Jerry


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## TonyWalsham (Jan 2, 2008)

Filtering the output of a pwm track side speed controller is not the same thing as filtering the output of an individual on board ESC. 

The circuit Sierra had available was designed for using Sierra sound with a pwm output on board battery powered ESC. 
I can guarantee you it works for what it was designed to do. 
I know because my, still available, # SSI-12v5 interface is based on the Sierra circuit and was used with the permission of Soundtraxx. 
I can guarantee you the # SSI-12v5 will work with the REVOLUTION using Sierra. 

BTW. If you do not use the opto interface with Sierra steam and power the Sierra with the traction batteries , a common ground is present and just like the diesel sound, the Sierra ramps to a full speed position. 
For steam that does not really matter unless you want the "at idle" effects such as the generator going on and off at the appropriate times and coal shoveling to take place automatically. The opto allows that. 

If you use the Sierra with its own battery and power the Sierra via the motor reference voltage, you will not need the opto interface on the motor voltage. You will however, need either optos or small relays on the sound trigger circuits to get them to work. 

I will indeed be interested to see what AC comes up with to filter the track voltage to achieve a linear output to suit LGB and QSI equipped locos.


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## Jerry McColgan (Feb 8, 2008)

Posted By TonyWalsham on 10 Jun 2010 05:51 PM 
Filtering the output of a pwm track side speed controller is not the same thing as filtering the output of an individual on board ESC. 

The circuit Sierra had available was designed for using Sierra sound with a pwm output on board battery powered ESC. 
I can guarantee you it works for what it was designed to do. 
I know because my, still available, # SSI-12v5 interface is based on the Sierra circuit and was used with the permission of Soundtraxx. 
I can guarantee you the # SSI-12v5 will work with the REVOLUTION using Sierra. 

BTW. If you do not use the opto interface with Sierra steam and power the Sierra with the traction batteries , a common ground is present and just like the diesel sound, the Sierra ramps to a full speed position. 
For steam that does not really matter unless you want the "at idle" effects such as the generator going on and off at the appropriate times and coal shoveling to take place automatically. The opto allows that. 

If you use the Sierra with its own battery and power the Sierra via the motor reference voltage, you will not need the opto interface on the motor voltage. You will however, need either optos or small relays on the sound trigger circuits to get them to work. 

I will indeed be interested to see what AC comes up with to filter the track voltage to achieve a linear output to suit LGB and QSI equipped locos. 

Hello Tony,

I wish I understood what you just said (really).

What is a ESC?

What is the SSI-12v5? How would it be wired and what would it do? Where is it available and for how much?

Is the SSI-12v5 any different from the Sierra RC adapter and why would it work with the REVOLUTION using Sierra if the Sierra board does not seem to be working right?

What is a traction battery? A battery pack?

"If you use the Sierra with its own battery and power the Sierra via the motor reference voltage, you will not need the opto interface on the motor voltage. You will however, need either optos or small relays on the sound trigger circuits to get them to work." 

You lost me there again. Are you saying there is an easy, inexpensive way to make the Sierra board compatible with PWC from a Revolution?

Jerry


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## TonyWalsham (Jan 2, 2008)

ESC = Electronic Speed Controller. The standard abbreviation for such items. 
I make the #SSI-12v5. I explained this all to you once before in another thread. It is more or less the same as the original Sierra opto circuit. 

I am not clairvoyant so when you say the Sierra board seems to be not working right I don't know what you mean. 

A traction battery is the battery used to power the whole locomotive. As distinct from say a back up sound battery. 

There are two ways to use Sierra. Either with or without its own back up battery. 
I gave two explanations as to what happens if you use one or the other methods. 

*"If you do not use the opto interface with Sierra steam and power the Sierra with the traction batteries , a common ground is present and just like the diesel sound, the Sierra ramps to a full speed position. 
For steam that does not really matter unless you want the "at idle" effects such as the generator going on and off at the appropriate times and coal shoveling to take place automatically. The opto allows that."* Explains what you need to do without a Sierra back up battery. 

*"If you use the Sierra with its own battery and power the Sierra via the motor reference voltage, you will not need the opto interface on the motor voltage. You will however, need either optos or small relays on the sound trigger circuits to get them to work."* Explains the way it works and what you need to do with the back up battery. 

The SSI-12v5 will do what you want. 
Contact either Dave Goodson or Don Sweet.


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## Jerry McColgan (Feb 8, 2008)

Posted By TonyWalsham on 10 Jun 2010 06:51 PM 
ESC = Electronic Speed Controller. The standard abbreviation for such items. 
I make the #SSI-12v5. I explained this all to you once before in another thread. It is more or less the same as the original Sierra opto circuit. 

I am not clairvoyant so when you say the Sierra board seems to be not working right I don't know what you mean. 

I have a terrible memory and I am not skilled with electronics. I need such things dumbed down for me to understand them.

Much of what I read goes over my head and whatever I may have read is often forgotten by the time I get around to trying to do something.

George had described the problem with the sound not starting until the loco was already moving fast. I had the same results.

I was trying to better understand what you were saying. 
No further explanation is necessary.


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## George Schreyer (Jan 16, 2009)

The Sierra was designed to work from the motor terminals when using DC track voltage. Most locos will not start to move until the track voltage is above 3 volts or so, somewhat less for USAT, more for some LGB. The Sierra does not detect that the track voltage has risen until it gets above about 2.5 volts DC. This works well for track powered locos because that is where they start to move. 

When you hit the motors with pulses, they start to turn well before the average track voltage rises above 2.5 volts and the loco can be moving along smartly before the sound picks up. This is what the circuit I designed ended up doing. As soon as it sees ANY pulses, it steps the DC voltage to the Sierra input to 3 volts or so, enough to get the loco off idle and into Run 1. The loco RPM ramps up in preparation for movement. Then as the pulse width increases and the motor starts to respond, it ramps up the input voltage smoothly causing the Sierra to run through the rest of the RPM steps. My version of the circuit is designed to reach run 8 at about 5 to 6 volts into the Sierra, right where it will make a Run 8 sound when the input sensitivity is set to the "high" setting. This is to allow the whole input range to occur before the voltage gets high enough that the Sierra wants to take some charge and draw current from the inputs. The optoisolators cannot source that current anyway.


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## TonyWalsham (Jan 2, 2008)

George, 
You are absolutely correct with respect to diesels. 
The optos I use switch on at .7 of a volt pwm. When running on traction battery power and no Sierra battery, terminals # 7 & # 8 see that .7 of a volt and will start ramping up. The actual starting setting can be adjusted a bit, although I have never actually got them right deliberately. I have got them correct accidentally. I simply do understand their programming instructions. 

With steam engines using a mechanical chuff timer operation, this is academic. The chuff starts as soon as it triggers.


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## Jerry McColgan (Feb 8, 2008)

Some projects are more trouble (time, energy and cost) than they are worth. Since I already have some locos with Sierra sound units in them and some spare Sierra sound units I was toying with putting Revolutions in them but it was not critical. The locos I run on the club layout are already 100% Revolution equipped and I just want to add one switcher with hook and loop couplers. I can do that with a Sierra RC adapter board that I have and even if it is not perfect it will do until Aristo comes out with the Consolidations which are what I really plan to use for switchers anyway.

On some non-Aristo locos where I was thinking about putting the Revolution between the track inputs and the motherboard I liked the idea of a DPDT switch (I think Jim suggested it) that would enable me to flip between analog track power and Revolution power. That way I could have moved those locos between my track powered and Revolution powered layouts. To do that I would have needed to be able to use my current Sierra sound units but considering the low cost of the Dallee sound units a PWC adapter would have to be inexpensive to buy ready made or easy for me to make.

When I get the GP-38 back together (today hopefully) I will be able to start trying to tweak the sound system to get the best speed ramping possible from it.

Thanks to everyone for their comments and suggestions,

Jerry


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## George Schreyer (Jan 16, 2009)

Dallee, while not having great sound, do integrate well in most configurations. You don't have to do much to get them to play "properly" but they never sound really great.


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## George Schreyer (Jan 16, 2009)

BTW, I have integrated DCC, Dallee, the older TE, battery and track power and an Aristo accessory switch board into one tiny loco, an LGB 2060. It was tight, but not electrically difficult. 

The thing will run on practically anything although PWC on the track SOMETIMES confuses the DCC decoder. The big trackside RX seems to do ok, but where I use an old TE onboard RX to power the track, the Digitrax DCC decoder freaks out. 



http://www.girr.org/girr/tips/tips6/2060_dcc_tips.html


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## Jerry McColgan (Feb 8, 2008)

Posted By Jerry McColgan on 10 Jun 2010 01:41 PM 
I can tell a diode from a resistor but I cannot follow current electronic circuits. 

The Revolution puts out PWC and my Soundtraxx Sierra diesel sound units do not work right with PWC. OK, I know Aristo is coming out with a PWC to linear adapter for their Trackside 

It seems that I need to get my eyes checked. If I had read correctly I would not have had any reason to start this topic.

I had incorrectly thought the new Aristo PWC to linear adapter was just for use with the Trackside Base Station. I did not think it was intended for use inside a loco with a sound system (perhaps because I saw it mentioned on the Aristo Forum under the topic "New Base Station").

My mistake.









What Lewis had actually posted was:

"We will have an adapter board ready in a few months for those people with older Soundtrax boards for instance.

All the best,
Lewis Polk" 

An adapter board for a Base Station was one thing but an adapter board that will work inside a loco with a Sierra sound system is a completely different thing and something I can wait for.









Jerry


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## Greg Elmassian (Jan 3, 2008)

Jerry, Aristo (in the form of the president of the company) has declared that they are more interested in using the new Trackside as an onboard for multiple locos. This has been clearly stated in the Aristo forum. 

Since the "Trackside" has been renamed the "Super Receiver", and due to the fact it also has the function outputs for a sound card, I can see their reasoning. 

So, with the above information, you can see that the usage of one of the (yet another) boards being produced will be to allow usage in a loco. 

If the now "adapter" can handle 15 amps is what I want to see. I would be surprised if this comes about, unless it is nothing more than a bridge rectifier and/or a big capacitor. 

Another $20 to add to the installation... you have to appreciate the clever marketing. 

Regards, Greg


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## Jerry McColgan (Feb 8, 2008)

Posted By Greg Elmassian on 11 Jun 2010 10:56 AM 
you can see that the usage of one of the (yet another) boards being produced will be to allow usage in a loco. 

Another $20 to add to the installation... you have to appreciate the clever marketing. 

Regards, Greg 

Hi Greg,

The trouble with marketing is that it is very difficult to determine where limited funds (even large corporations have limited funds) are to be spent.

On the one hand how many fewer Revolutions would be sold if everyone had to pay more to have PWC that most may not need and be unwilling to pay extra for - especially when the primary need for it appears to be for a sound system that has been discontinued and the manufacturer has left the large scale market?

On the other hand is the potential for some lost Revolution sales if the extra cost for a PWC adapter keeps some people from buying the Revolution.

Since Aristo is playing with private funds I am happy to let the one who has the most to gain or lose decide where he wants to invest his money.

The way I look at it Soundtraxx was selling their adapter for a MSRP of $25 (several years ago) so, as long as a PWC adapter is or becomes available at a somewhat comparable price, it leaves me the freedom to adjust my future Revolution purchases according to the net cost per loco and the importance to me of having that loco Revolution controlled.

I never convert everything to anything so I am always free to adjust my plans according to the toys that are made available to me. 

Regards,

Jerry


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## Greg Elmassian (Jan 3, 2008)

I was more referring to the multiple add-ons that can be necessary with this system... the board itself and an additional cap board, a smoke board, and now a pwm "filter" board. So you could have an installation with 5 boards counting the sound board. 

Regards, Greg


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## Jerry McColgan (Feb 8, 2008)

Posted By Greg Elmassian on 11 Jun 2010 01:49 PM 
I was more referring to the multiple add-ons that can be necessary with this system... the board itself and an additional cap board, a smoke board, and now a pwm "filter" board. So you could have an installation with 5 boards counting the sound board. 

Regards, Greg 

Hi Greg,

OK I missed your point. I have no idea why it was done the way that it was. 

Some Very Good News!

For some reason putting the Revolution into this GP-38 with the Sierra sound board has proven to be the most intimidating Revolution install I have done. Certainly the others were much easier because the Aristo locos with the PNP interface, Revolution, and Dallee sound systems were all made to fit and work together but even so the install for the GP-38 was not particularly complicated. I did not even have to assemble the Sierra RC kit as I had done that some time ago (but I did have one solder joint that I had missed).

Where the other installs went from a day or so for the first (I am a slow worker) to 4 in a day this GP-38 has taken me almost a full week to talk myself through it.

I was running into the mentioned problems with the sound and motor not running quite right but I finally figured I had it as best as I could get it and put everything together and put it on the track.

Quite frankly I was really surprised in that everything worked much better than I had anticipated. While there is a bit of a delay in the sound ramping up the sound comes on immediately and the delay is not that noticeable (I don't know if real diesels change sound as soon as they start to move anyway).

I suspect that what may have been happening is that I was testing the loco with the frame and trucks laying on their side so there was no drag to the wheels turning. On the layout with the wheels having to carry the weight of the loco they take somewhat higher voltage to get moving. I did notice that the red flashing light that indicates when the sound is supposed to ramp up is accurately starting to flash exactly at the voltage I set it to (within 1% on the Revolution screen).

All in all I am now very pleased with the installation and I will go ahead and use up my last 2 Revolutions and last 2 Sierra RC adapters.

Jerry


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## George Schreyer (Jan 16, 2009)

Actually, real diesels rev up, make noise and smoke BEFORE they start to move. The energy needed to start a train has to come from somewhere.


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## TonyWalsham (Jan 2, 2008)

Jerry, 
Correct me if I am wrong, but wasn't the Soundtraxx PWM adaptor sold as *a kit of parts* for US$25.00? 
If so, I would be glad to supply the the RCS #SSI-12v5 parts as a kit for the same amount. 
The difference between that price and what I sell them for made up, is my labour. 
I cannot work for the slave labour rates the Chinese workers are exploited (and often die) for.


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## Jerry McColgan (Feb 8, 2008)

Posted By TonyWalsham on 11 Jun 2010 07:44 PM 
Jerry, 
Correct me if I am wrong, but wasn't the Soundtraxx PWM adaptor sold as *a kit of parts* for US$25.00? 
If so, I would be glad to supply the the RCS #SSI-12v5 parts as a kit for the same amount. 
The difference between that price and what I sell them for made up, is my labour. 
I cannot work for the slave labour rates the Chinese workers are exploited (and often die) for. 
Hello Tony,

I had no idea what your prices were. That is why I asked. I was seriously interested or I would not have asked. I do not question your labor rates as I am sure that they are fair. Assuming that your kit includes a circuit board I would be interested in it if I need another (my labor for myself is free).

When Davis Trains went out of business I bought three of the kits (I had no idea what they were for) along with the Sierra sound systems they had left. You are right, the kits had a MSRP of $25 which included the circuit board. 










They later released the instructions alone so folks could buy the parts at Radio Shack and build their own. 










I have never priced the components but I do like having the circuit board to build on. As far as I know Soundtraxx did not sell the circuit boards by themselves.

When I asked about your board I did not think my Sierra boards were going to work. If they did not I would have been unable to complete the GP-38 I was working on. I would have needed something right away.

As it turned out I am pretty happy with the way the Sierra board is working so that gives me one plus two more sierra sound systems I can install with the Sierra adapters I have.

Once I finish the other two (I don't know when that will be) I don't know for sure if I will be installing anymore Revolutions as I will be in pretty good shape. If I do need a 4th PWC adapter and the Aristo one is not available by then I will get back to you.

Thanks,

Jerry


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## TonyWalsham (Jan 2, 2008)

Jerry,

All parts needed are included. 
The pcb is not screen printed but a diagram is provided for locating parts. 

Whilst you may not need such a device right now, there are plenty of other REVOLUTION owners who may want such an interface right now for their Sierra sound systems.
I can help them. 
So thanks for bringing the subject up.

The # SSI-12v5, and lots of other neat installation accessories can be found HERE[/b].

Full details of the # SSI-12v5 can be found HERE[/b].


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## Stan Cedarleaf (Jan 2, 2008)

Posted By TonyWalsham on 11 Jun 2010 07:44 PM 
Jerry, 
Correct me if I am wrong, but wasn't the Soundtraxx PWM adaptor sold as *a kit of parts* for US$25.00? 
If so, I would be glad to supply the the RCS #SSI-12v5 parts as a kit for the same amount. 
Tony............
Tony, you are correct. The Sierra adapter board kit sold MSRP for $25.00 US. There was a time that the street price was around $19 but when the supply from Soundtaxx was cut off, the price remained at $25 from dealers that still had them. I'm pleased to see that you would supply a "Kit" for your product RCS #SSI-12v5 for that price. Would shipping be from AU or here in the US? Thanks for making that available.


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## TonyWalsham (Jan 2, 2008)

Air postage for a single item would be about US$3. 
I could offer a package deal of 5 x kits for US$100. One set of instructions. 
Air Postage would be about US$5


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## Jerry McColgan (Feb 8, 2008)

Posted By TonyWalsham on 11 Jun 2010 08:42 PM 
Whilst you may not need such a device right now, there are plenty of other REVOLUTION owners who may want such an interface right now for their Sierra sound systems.
I can help them. 
So thanks for bringing the subject up.


Hi Tony,

I bring up topics 50% for what is in it for me and 50% because I think that what is a problem for me may be a problem shared by others.

If my needs have been met (for now) but the needs of others may be met through you then I have not wasted everyone's time reading about my problems.

Thank you for your contribution.

Cheers,

Jerry


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## Stan Cedarleaf (Jan 2, 2008)

Sounds like that might just work, Tony. I'll be in touch.


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## aceinspp (Jan 2, 2008)

As Stan mentioned the circuit he use and built for the Sierra board is nothing like you posted Jerry. Later RJD


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## Jerry McColgan (Feb 8, 2008)

Posted By aceinspp on 14 Jun 2010 04:54 PM 
As Stan mentioned the circuit he use and built for the Sierra board is nothing like you posted Jerry. Later RJD 

I'm not sure what you mean. As far as I know Stan and I are both using the same Sierra circuit. It is possible that I am using the circuit including the Sierra board and Stan is making his own board but I believe the circuit is the same. Actually I am pretty sure that Stan is using the exact same circuit including the Sierra board. 
This is the Soundtraxx RC Adapter Kit part number 810111 that I am using:

http://1stclass.mylargescale.com/je...erface.pdf

This is how I am wiring it with the Revolution:












At one time I may have mentioned a small circuit for using analog sound systems with DCC. I had thought it might have worked with PWC but it did not.

Of course I could be wrong. It would not be the first time or the last.

Jerry


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## Trains West (Oct 4, 2008)

so if the problem is that the loco moves before the sound starts then why not kill a few volts that go to the motor and not the sound with diodies or tied off full wave bridges ( ac arms together) two in line would kill 3 volts


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## Stan Cedarleaf (Jan 2, 2008)

Hi RJ.... Just a clarification on the circuit (board) I'm using for the Sierra diesel modules with the REVOLUTION. 

I am using the same Sierra adapter board that Jerry shows in his diagram. I've tried some other "stuff" and the only thing that I've found to work with the diesel modules is the Sierra adapter. 

I haven't tried Tony's board but it sounds like in would work right nicely. He's made them quite attractive price wise for the kit.

I don't have any diesel installs coming up in the near future and still have 2 Sierra adapters left.


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## TonyWalsham (Jan 2, 2008)

The RCS # SSI-12v5 is nowhere near as complicated as the board shown above.
The # SSI-12v5 is based (with permission) on the original opto isolator circuit issued by Soundtraxx which did not include a voltage regulator. The # SSI-12v5 does have a voltage regulated supply for the Sierra.
The # SSI-12v5 does not have a bridge rectifier to take power from the track. It will require a polarised DC supply. Polarity protection is via a1 amp diode.


I would suggest you read up on it here: # SSI-12v5 Instructions[/b][/b]


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## George Schreyer (Jan 16, 2009)

That works but it also kills top speed.


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## TonyWalsham (Jan 2, 2008)

George. 
When you say "it kills top speed", do you mean the sound will not ramp up to Notch 8?
It will ramp up to top speed, provided you use the provided 12 volts to power the Sierra fed into terminals # 2 & # 4 as shown in the instructions.


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## rmcintir (Apr 24, 2009)

Posted By George Schreyer on 19 Jun 2010 09:24 AM 
That works but it also kills top speed. 
That's why a controller that can go to 11 is required!


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## George Schreyer (Jan 16, 2009)

I should have been more specific. If you use diode stacks to retard the motion of a loco at low motor drive, then it also retards the loco at high drive when the PWM signal essentially becomes DC. In many cases, this is ok, the locos run too fast anyway. But for mainline passenger or fast freight service, the locos may just run too slowly.


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