Cows that moo

 Bindlestiff,

You might be able to use the triggers to route the speaker output to the correct speaker with a relay or look for a trigger that has multiple contacts. Sounds like a great idea. My club uses wireless throttles from Aristocraft and they have aux contacts that we use to trigger tape players with loop tapes right from our handhelds. We want to switch to some thing digital so maybe this might be good for us. Keep us posted on you progress.

Barry Rosier

Strasburg Model Railroad Club

"The Road to Paradise"

+ +

This is known as multyplexing.  you have 2 options, manual or automated. Automated is what you want.

As mentionned by others, this would require  as many relays as there are sound points (speakers). 

Also  needs some logic trigger to attache the detection or sensing device too.  Something similar to a DS64/DS54 could suit the bill.  Anything that has multyple inputs and multyple outputs.  The inputs would be your sensing device. The ouputs must sink a few volts to activate the relays.  View the outputs as turnout motors. 

The sound source (MRC gizmo)  would then have a common bus to the relays on the center tap  to route the sound. To trigger the sound we use the third pole of the relay.   Requires triple  pole/double throw relays as the relay is routing the sound and triggering it.   You might get by with double throw/ double pole if you wire one side of the speakers as a common return.

Drew up this diagram to give you an idea what would be involved..

A -  Your  MRC sound device. 

B-  Turnout controler, DS54, DS64, or other similar device. But these would require a mechanical trip trigger.   Could use reed switches and the timed outputs  integrated into most turnout controlers.  Fancier solid state solution will require  more electronics to activate the turnout controler.

C -  Three pole / double throw relay. Allied Electronics sells these.  $80.72 for 10. You could also  get by with DP/DT relays  (DigiKey  PB383-ND,  $2.14) and wire up turnout return common and speaker return common.

D -  Triggers; reed switch /magnets.   Any optical type, field effect transistor, BOD  option  will require more electronics (to power the device and amplify the signal to the proper voltage levels.

So in all it will cost more than $10 per sound.  But it is dooable.

Hope this helps you along.

This might be worth a look.

This might be worth a look. The Dream switcher by Pricom Design. I'ts designed to work with their Dream Player but the info says it can work with any audio source. It has 4 speaker outputs with only 1 in use at any time.

http://www.pricom.com/Trains/DreamSwitcher.shtml

cheers Steve

+ +

Nice device that is,  Comes to what  our friend  is looking for. This one has the advantage of accepting new sound files via the mem card and the sound quality will be as good as your recordings are compared to the MRC gizmo. They are also working on a JMRI interface for the Dream Player/Dream Switcher using the RS-232 port.

Still you need external triggers to get automation  and he shows a solution using  BOD (Block Occupancy Detectors)  from Team Digital.    This is the type of additional electronic I was referring to, BOD, either current sensing or diode leak.  These can also be used with the  turnout controlers.  or you go the reed switch/magnet route. 

When you look at both solutions, they are close on the price range once you get all the electronics together and wired up. 

Only catch with this solution is he allready purchased the MRC sound gizmo for $30..

Marc

There is another way to go

There is another way to go and that is using photo interrupter circuit. see this following tutorial one you read it and see the photos you just need to find some of the old electronics that contain these circuits and the parts like old printers, broken VCR's and a number of other product. see the URL below  for a tutorial

http://cirictech.com/?p=51

you do need to know a little about Digital electronics Like Vcc means + voltage in-- Gnd + Ground and Sig means the light from a LED as the signal activator.

VCR's use the type interrupter circuit you can use activating your (Moo) circuit as when the train passes in front of the LED it blocks the light that shuts the circuit off and the photo interrupter then turns the circuit you want activated like in a VCR when the clear tape allows light to pass through to the Photo interrupter Transistor no picture would be broadcast to the TV once the Dark Tape blocked the Light aimed at the Photo interrupter transistor it turns on the video feed. Lionel Trains makes a little remote circuit that works on this principle if this is out of your range of electronics. Don't feel bad if you don't understand it as 90% of the world don't and I'm very sorry I'm no teacher just an adviser.

NOTE: the basic Idea for this circuit is to be the switch to turn on the (Moo) circuits as the train passes the interrupter circuit set up on the tracks just before reaching the speaker of what ever you sound will be broadcasting.

Dan

Dream Players

Thanks Marc for taking the time to post the circuit.  It does seem that the Dream Switcher should meet the need. I glanced at the web site and it appears that the Dream Player is vastly superior to the MRC unit.  Still though automating sound with four outputs would cost $110 plus speakers plus switch/triggers.  Superior sound though.

I'm a foot in the door kinda guy.  The $25 MRC unit (from Modeltrainstuff - MRH ad sales send them a solicitation) gets me started.  For now, the plan is to put a speaker in the barn and let the cows, roosters and chickens sound off there.

Last year I ponied up  about $160 for  a pair of NJ International crossing gates and the Logic Rail Technologies board, card, speaker, infrared (IR) sensors and Tortoises to make the thing work.  Then I learned that I needed more IR's and another logic board because of my double track situation.  So I just put the project on hold and built some more scenery. I'll get back to it though.  In the mean time, I'll steal the IR's and use them to make those cows moo.

But then it's not so simple because a detector circuit is needed to allow the IR's to do any good.  Maybe I'll just add some momentary contact switches in the fascia and the grandkids can make the cows moo.

+ +

IR or any optical detector is nice but require wiring for power and detection feedback. The ones suggested by Dan are difficult to apply to a railroad as they work by obstruction of the IR beam between transmitter and received  and they are close together. 

But it got me thinking.  What if you mount  the emitter ( IR LED) under the  tender or any rolling stock, power it from track power (about the amount an LED would require)  and point it at the track . Mount the received between the rails.  So when the rolling stock (and emitter) pass over it, bingo, detection. You could have two emitters in a row,  just  to give you that much more chance of being detected.    

Another option is the NCE BD20 ($12). It does not require anything but a loop of  feed from track going thru it.  

You can also get it to trip your relays by adding a power source of 5V and having this feed direct to your relays. This would remove the turnout controler from my diagram.   Using the BD20 with relays is covered in the BD20 manual.  The manual also covers using it with logic level current/voltage. This might be a solution to both your issues, MRC and NJ Int.

Random Switch Generator

After giving my first idea some though, I realized that using train movements to trigger the cows mooing probably wouldn't be effective.  I mean the train would go by  and the cow would moo.  Ah so what.

The issue is that it would take way too many train movements to generate enough triggering events. The train goes over the sensor.  The cow moos and that's it.  The cow doesn't moo again until another train goes over the sensor.  While with the bell ringing and the lights flashing with a crossing signal stay happening until the train as passed with the MRC thing you press the button, the cow moos and stays silent until you release the button and press it again.

So I guess what I am looking for is some kind of random sequencer   or even something simpler like whateever makes the lights twinkle on a Christmas tree.  There oughta be something.  Any ideas will be welcome and considered  even if not adopted.

+ +

  I have not tried it but put one of these blinking bulbs in the circuit and you should get random cow moo.  By-metal  curls when power is applied, eventually opens circuit. Cooling lamp closes the circuit again and the cow goes on.   For a sample of operation click on the bulb ...

Nice

Tres Bien, Marc.

That was one of the more novel sound effect machines.  Now, if you'd just bring back your thumbnail mug shot and animate it,  we'd have the complete package.