Steam chuffing sounds without chuff trigger?

Lee- please don't hold me to this, but I think the MRC Steam "Sounder" chuffs based on input voltage. At least I know it does on the HO version I installed for a neighbor on an older HO steam engine. It actually worked rather well considering its price. I put a better speaker in as well.

I believe there is an O gauge version of the MRC sounder but not 100%

Mack

Most of the DCC sound systems work without any triggering hardware. On my OO models, they are all determined within the electronics based upon the speed setting. i don't know whether this is from the motor voltage, or internal logic though.

Lee- just checked the forum archives and MRC site and looks as if AC Sounders were discontinued several years ago. Maybe you can find a steam sounder on the "want to buy" forum

Mack

Nicole- that is correct. I have several ESU and Zimo sound decoders in my Hornby OO steam engines and they are awesome how they interpolate the correct chuffing based on voltage and BEMF (I think!) However they do it, it is so easy and no messing with reed switches and magnets.

Mack

IF, Big if, they use a VCO you might be able to just add bridge rectifier to the input.

Making one using a VCO coupled to a divider should work. You should be able to google the circuits for these and it should not take too many components.

Pete

MTH command and Locosound use the tach strip to trigger chuffs.  MTH ProtoSound 1 boards determined the chuff from the voltage.

MTH PS-1 sound systems don't use a switch, but use the track voltage to set the chuff.  If this is for your quad steamer project, you can get to board sets and order chips for the Cab Forward or other articulated engine to get the sounds.

Lee, if you can fit a PS/1 board in, drop me an email.  I can get you the chip from MTH of your choice, and I have PS/1 board sets.  I'm sure I'm due to do you a favor.

PS-1 chuff rates are adjustable, too. They can be set to start, increase, and reach maximum at appropriate voltages.

I have actually asked ERR about this a few years back; it seems to me that if we can

program various features now that it would not be too great a stretch to have a

software solution to the chuff-rate issue.

The steam sound system would allow the operator to choose between 3 or 4 chuff rates

to be selected from the CAB-1/2/1L and set much like momentum, etc (AUX 1-something-something). The rate would vary up and down based on an algorithm (Oo!Oo! I finally got to say "algorithm"! Just like on TV!) using motor RPM data (GOT to be available to the board in some formor other) as input. The chuffing "bark" would be inferred from the amperage (the work done) being drawn by the motor (heavy train,more amps; more accurate than voltage to determine the "labor" of the sound - and I -know- that the driver board knows the amperage - it's what's feeding the motor).

One would select rate 1, 2, 3 or 4 based simply on what looked right for that locomotive/driver diameter/speed. An approximation, but a better one than an

axle-mounted magnet system.

My concern is that all the above is pretty simple stuff for an electronics type, and I

am SURE that I'm not the first genius (thank you, thank you) to come up with it,

yet, where is such a system? What am I missing? 

You mean like the ERR sound command boards which have a connection to the motor when its a diesel?  Why not use the same connection for a steam engine instead?

That connection must sense the voltage to the motor to increase the rpms for the prime mover.  It may trigger the steam chuffs.

Yes - that's the idea. Diesels rev up and down - though I still don't like the use of 

voltage to do it - so could not a similar, but programmable for different driver sizes,

system be devised for steam? 

Voltage really doesn't tell us much. An O-gauge F-3 A-unit with no train running at

100 smph is actually drawing, say, 12 volts, but is actually not working very hard at

all (drawing few amps) - so the sound should not be very "labor-intensive". Real diesels and steamers work the same way - and amperage would better reflect this in our models. 

Thanks everyone.  I have PS1 cards and may look at that.  I went ahead and built the chassis of my 2-8-8-8-8-82 loco (separate posting) with chuff magnets and sensors on the pilot wheels from and back, but I'd prefer to switch out to larger pilot wheels that are more "prototypical" if that word can be used for that loco, since it apparently would have had large front pilot wheels.  Anyway, I will look into the options listed.  Again, thank you everyone!

Lee...look at this stuff...http://www.tcsdcc.com/public_h...s/WOWSound/index.php

DCC obviously but perhaps might help you.

Bob