I can't remember where I heard about it but does any know how to make one of have you heard of a DCC squealer? The way it works is that when a short circuit occurs in a zone the squealer which has a horn of some sort on it sounds out a tone until the short is repaired or power is shut off. From what I can remember it must be a pretty simple circuit.
It also sounds like a pretty annoying circuit!
The automotive bulb in series with track power is at least as noticeable, and can be left on while troubleshooting - breaking the short causes it to go dark. I can imagine trying to troubleshoot with a horn blowing continuously - but I prefer not to.
Chuck (Modeling Central Japan in September, 1964)
http://index.mrmag.com/tm.exe?opt=S&sort=A&output=3&cmdtext=%22SHORT%22
Audible Short Circuit Detector by Don Hansen, page 104, May 1984. Includes a circuit diagram and part list for the do it your selfer. There is a provision for a light if a visual indicator is also needed. This device was for use with transistor throttles, so I don't know if it would work with DCC.
Quoting from the article and reflecting the post above, "My alarm makes an annoying sound".
At the Greeley Freight Station Museum (Dec. 2008 MR), we have 17 DCC boosters to cover 70 scale miles of track. Most of our boosters emit a high pitched squeal when there is a short. The high pitched squeal sounds like it is coming from everywhere and is difficult to determine which direction it is coming from, let alone which booster is down. I developed a DCC Detector that signals the computer when a booster is down. The booster is then identified on the display and signals are set to red to stop trains from entering the shorted booster.
The DCC Detector also flashes a bright blue LED on the fascia. This helps operators to zero in on the short. If anyone is interested in more information on this, please contact darrel@dgandc.com.
Darrel
cmmodeler I developed a DCC Detector that signals the computer when a booster is down. The booster is then identified on the display and signals are set to red to stop trains from entering the shorted booster.
If you're using Digitrax PM42's, this is easy to set up with LocoNet and JMRI.
You can even have your computer make a verbal announcement of which power district has been shut down.
Or sound bells, flash lights, whatever.
CVP easy DCC has a buzzer built into the booster that goes off when there is a short. It can be annoying at times but it sure keeps operators on their toes to avoid hearing the dreaded FWEEEEE!!!
I have operated on other systems and have found it odd to short and not hear it.... I have come to rely on the buzzer to let me know there is a problem....You don't want shorts to be continuous in DCC. The buzzer is helpful in imparting a sense of urgency to the task of getting the problem fixed...
I'm sure installing an audio alarm of some kind would be pretty easy. I suppose the question is: Are you sure that you want it??
Guy
see stuff at: the Willoughby Line Site
It should be really simple to do. Get a full wave bridge rectifier and connect AC input to the track. Next get a 14 VDC relay that draws very little current. Connect the relay coil to the DC output of the bridge rectifier. When there is power on the track, the relay will be closed. Use the relay contacts as a switch to turn on a buzzer when the really opens. (no power).
If you don't understand these instructions, you don't have the knowledge to set this up, and shouldn't attempt it on your own.
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
Don't all DCC systems have some kind of short notification? Sure having a lot of boosters can make it a problem if you are running a lot trains but for the average layout running one power source it seems like making a short detector is over kill. My Digitrax SEB will start beeping when there is a short.
However, if you have circuit breakers downstream of the booster, the booster won;t trip and beep, and not all breakers have an audible indicator - in fact most don't. Usually just LEDs ont eh board, that if mounted up under the layout you don't see, but with provisions for some sort of external LEDs and/or a buzzer.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
If one uses the PSX series of circuit breakers from Tony's Train eXchange (www.tonystrains.com), one can add a Piezo buzzer to them. So when they trip, they sound off and it's quite noticable. And if you can't figure out with one is buzzing when you have 3 or 4 together, just place your finger over each buzzer. The one that muffles the sound is the obvious problem.
We have added the buzzers to all our PSX breakers at my RR club after someone let a short go on during a show for 15-30 minutes. D'oh!
Paul A. Cutler III
Here's how I added a piezo buzzer to our club's PM42's.
http://bantrak.net/clubdc-dcc.htm#DC/DCC_Remote_and_Audible_Short_Indication
Martin Myers
Next time we do Timonium I need to come over and introduce myself. Last time, it February, we were right next to your setup - I'm a member of the RCT&HS. Yoiu have all sorts of useful add-on gadgets and stuff.
Could you tell me where you bought the buzzers? Can you also use a bulb (led) with the buzzer on the PSX ? Thanks
Bob D
Bob D As long as you surface as many times as you dive you`ll be alive to read these posts.
tomikawaTT It also sounds like a pretty annoying circuit! The automotive bulb in series with track power is at least as noticeable, and can be left on while troubleshooting - breaking the short causes it to go dark. I can imagine trying to troubleshoot with a horn blowing continuously - but I prefer not to. Chuck (Modeling Central Japan in September, 1964)
LOL I have to agree with you, Chuck.
I find myself trying to imagine other techniques besides a blaring horn.
1. A zapper connected to your throttle which sends non-life threatening electrical jolts through your body until the short is resolved.
2. An overhead sprinkler system that turns on at the first indication of a short, turning off only when the short is resolved.
3. A dense fog machine that emits a room filling fog that only dissipates once the short is resolved.
4. A continous buzz similar to that annoying weekly emergency alert test on your TV that only ceases when the short is resolved.
5. A recording of your wife's voice repeatedly shouting, "There is short on your layout, Shorty" which only ceases when the short is resolved.
Rich
Alton Junction