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Grade Crossing circuits, Ding-Ding sound module

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  • Member since
    August, 2006
  • From: Franconia, NH
  • 1,935 posts
Grade Crossing circuits, Ding-Ding sound module
Posted by dstarr on Tuesday, July 23, 2013 5:14 PM

I have a grade crossing that needs a little protection.  Finally broke down and bought two lovely brass crossbuck with flashers and crossing gates models.  I want to install some leds on the gates and flash them too.  Started out with the sound.  I had an old Jameco sound kit, about 10 years old, been sitting in my pile of unbuilt kits.  Looks like this.

Not much to it, a tiny circuit board, a push button for each sound, a three inch speaker.  I used Goo Gone to clean 10 years of corrosion and crud off the contacts and make them solder nicely.  Then we step back into electronic history, back when breadboards were actually made of wood.

A piece of soft pine to hold everything.  The push buttons are mounted on a piece of aluminum angle.  The whole thing will fit under the fascia, and for the time being I'll sound the crossing dinger by hand, pressing the push button.  Later I'll install train detection to trigger the sound automatically.  One thing at a time. The whole thing runs off pen light cells. 

Got it all soldered up.  It works.  Could be a little louder, but maybe the sound has been scaled down 1:87.   Or I could add another transistor to boost the sound level.   The sound isn't too bad.  This kit is no longer on the Jameco website, but there are a couple of newer ones and the price ain't bad. 

  • Member since
    February, 2002
  • From: Reading, PA
  • 16,846 posts
Posted by rrinker on Tuesday, July 23, 2013 6:58 PM

 Looks like the same sound chip they use in greeting cards, so that probably explains a lot about the volume and the price (at least, i HOPE it was inexpensive). And probbaly the availability, I haven;t seen a card with a grade crossing bell sound in a long time. However, peruse the selection of sound cards, in among all the ones with a song recording, there might be some with sounds that could be used on the layout. They run a long time on a watch battery, so the set of AA batteries should REALLY last a long time.

             --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    November, 2005
  • From: Phoenix, AZ
  • 347 posts
Posted by woodone on Tuesday, July 23, 2013 7:10 PM

Put the speaker into some type of enclosure. Sealing off the front to the back and I bet the volume will double!

  • Member since
    August, 2006
  • From: Franconia, NH
  • 1,935 posts
Posted by dstarr on Tuesday, August 06, 2013 3:51 PM

woodone

Put the speaker into some type of enclosure. Sealing off the front to the back and I bet the volume will double!

Did that.  Actually I found a better three inch speaker, heavier with more magnet, scrounged out of a dead set of computer speakers,  and made a very small enclosure for it.  All wood enclosure.  Then I sank it into the two inch foamboard that underlays the crossing.  Painted it earth tone to blend into the ground cover.

 

The enclosure and the better speaker brought the sound up to just about the right level, loud enough to hear, but not so loud as to seem unreasonable for an HO scale crossing flasher.  Then a structure atop the speaker and it's outta sight.

For now, we have some buttons to make it sound off.  Track detection is coming. 

  • Member since
    November, 2007
  • From: sharon pa
  • 367 posts
Posted by gondola1988 on Wednesday, August 07, 2013 6:50 AM

I don't think that preacher is going to like your hard work with his church sitting next to your RR tracks LOL. Jim.

  • Member since
    November, 2007
  • From: sharon pa
  • 367 posts
Posted by gondola1988 on Wednesday, August 07, 2013 6:56 AM

By the way great work, I need to find 4 of those sound units for mine also. They just had a great IR track detection circuit on here that would work great for the sound and crossing lights. Jim

 

  • Member since
    August, 2006
  • From: Franconia, NH
  • 1,935 posts
Posted by dstarr on Wednesday, August 07, 2013 11:36 AM

gondola1988

By the way great work, I need to find 4 of those sound units for mine also. They just had a great IR track detection circuit on here that would work great for the sound and crossing lights. Jim

 

Jameco has some RR sound modules, later models than the old kit I had.  Prices were in the $20 area.  I have heard that you can still find toys and even greeting cards with sound chips in them, althought I haven't seen any myself. 

   I saw  a number of circuits here in the last couple of days.  Some of them were so complicated I couldn't figure out how they were supposed to work.  Some of them wouldn't work.  I am going to use Radio Shack photo transistors.  Connect the emitter to circuit ground, connect a load resistor between collector and Vcc.  When light shines on the phototransistor it will switch on and conduct, pulling the collector down to ground (a logic low).  When the photo transistor is dark, it shuts off, and the collector resistor pulls the collector up to Vcc, ( a logic high).   Proper value of the collector resistor is high enough to limit current thru the ON phototransistor to something the transistor can withstand.  I gotta read some data sheets to know what that might be. 

  Then there is the flasher circuit.  I'm thinking astable multivibrator, mostly cause I can remember how to compute the flash rate from an Air Force tech school I attended many many years ago.  And I can shut it off by pulling the bases of both the flash transistors to ground.  And I have the necessary NPN transistors in my parts collection.   And I can use 12 volts, and put all the LEDs in series thru one current limiting resistor and still have enough voltage across the resistor to make the LED brightness controlled by the resistor, rather than the uncontrolled forward bias voltage of the LEDS.

  • Member since
    November, 2007
  • From: sharon pa
  • 367 posts
Posted by gondola1988 on Wednesday, August 07, 2013 11:59 AM

Sounds great maybe you can put the circuits on here when your get them built and working. Going to check out Jameco haven't been on there for years, thanks for the info. Jim

 

  • Member since
    February, 2003
  • From: US
  • 846 posts
Posted by alloboard on Thursday, September 19, 2013 1:29 PM

Logic Rail Technologies might have an alternative of everything that you need.

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