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Reed switches and Turnout HELP-

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  • Member since
    April 2003
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Reed switches and Turnout HELP-
Posted by Anonymous on Monday, March 21, 2005 7:29 PM
Hello all I have posted this before and because I am electrically challenged I still have the problem. I need to auto mate my turnouts to switch the points to the proper direction when a train arrives from the frog side of the turnout, thus making the points point in the right direction.
Well I bought some reed switches which are rate far higher than the votlage that comes from the transformer and the reed swiches fuse and then burn up my atlas snap motors,
Since I am so ellectrically challenged I am hoping that there is someone out there that could tell exactly what I should buy and explain it in such a nuntechnical manner that my brain could absorb and use the info. I am hoping that someone out ther has done this and can really baby sit me through it by telling what to buy and how to install. As usual your help is greatly appreciated,
Thanks
JOn
P.S. runing Dc
  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Monday, March 21, 2005 9:29 PM
Reed switches cannot switch high currents, that is why they are fusing up. They should not be in series with the switch motors. It actually gets pretty complicated - the idea of the reed switch is that a magnet moved witht he points either triggers the reed switch or lets it open. The reed switch in turn powers a relay (since the reed switch can't handle track current, either), and the relay is what switches the frog polarity.
You have two basic ways around all this. One is the Atlas Snap Relay. This comes with instructions that show how to hook it up wih the Atlas switch machines to do what you want.
The other is to look at the Tortoise switch machines. They have the required contacts built in. Kind of pricey, but the other advantage is that they move nice and slow, no 'slamming' the points from side to side, and do not need momentary pushbuttons, and so are nearly imposisble to ever burn out.

--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
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Monday, March 21, 2005 9:32 PM
Never mind - I thought you were trying to power the frogs. You want non-derailing switches like the Lionel ones.

You need to add one more piece - a relay. Even that is pushing it, the high current demands of the switch motors are not good for the relay contact either, but they will hold up better than the fragile reed switches.
I need to check, but I think Circuitron or someone, maybe Berkshire Lines, has a circuit that does what you want, triggered by reed switches. It's pre-built, all you have to do is hook up the wires to the reed switch and the switch motor.

--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
    January 2004
  • From: Crosby, Texas
  • 3,660 posts
Posted by cwclark on Monday, March 21, 2005 10:49 PM
You may want to use just electric switches to throw your turnout points when the train aproaches the turnout...either an atlas slide momentary switch or a DP/DT for a tortoise machine...there is a way to set it up for automatic control which will require a train detection circuit , a relay, and three different power supplies to drive it all...if you use atlas equipment, it's going to be even more complicated because you'll need a short timing device to give the momentary power to turn on and off quickly so that you don't burn up the coils..with a flip flop and a timer.. if you use a tortoise machine then you'll just need a relay but will have to put a resistor across the wheel of the last car in the train so that it will hold the turnout points in the proper position so the entire train can leave the block before the relay changes positions which also will require a timer so that the points don't change until the entire train clears the points...you're getting into some major electronics to do what you want to do with the turnout...Chuck

  • Member since
    April 2003
  • 305,205 posts
Posted by Anonymous on Tuesday, March 22, 2005 6:06 PM
QUOTE: Originally posted by In training

.....I am electrically challenged I still have the problem. I need to auto mate my turnouts to switch the points to the proper direction when a train arrives from the frog side of the turnout, thus making the points point in the right direction.
Well I bought some reed switches which are rate far higher than the votlage that comes from the transformer and the reed swiches fuse and then burn up my atlas snap motors,
Since I am so ellectrically challenged I am hoping that there is someone out there that could tell exactly what I should buy and explain it in such a nuntechnical manner that my brain could absorb and use the info. I am hoping that someone out ther has done this and can really baby sit me through it by telling what to buy and how to install. As usual your help is greatly appreciated,
Thanks JOn. P.S. runing Dc


You first have to learn basic electronics and electrical work. Buy the Atlas wiring book to start. You should know things about diodes, resistors and capacitors and the properties of electricity.

It can be done, *but there is no device that you can buy off the shelf that will do all what you want to do. And it will be limited to one trafic pattern. If you don't know how to make printed circuits, it will be very costly (over $220 w/o power supply) to buy the devices. You have to know how they work to make them work together. If you can't, it's money wasted.

You need three detection circuits that are single direction, such as Circutron DT-3 @ $22 each, for each turnout. That would cost $132 for two turnouts just for the detectors.
Also a Capasitor Discharge Unit (CDU) to prevent burning up the turnout solenoid, for each turnout, such as the Circutron Snapper @ $30 each X 2 = $60
And possibly a relay for each direction of throw. About $5 each X 6 = $30
If you don't already have one, a separate 14 -18 volts, 2 amp power supply ($?)
That would work for a passing track, but if this is for a reverse loop, you will also need a reversing circuit such as the Circitron AR-1@ $42each (MRC reversing unit will NOT work with DC) and a much more complicated wiring scheme.

Basically the detection unit connects to a relay, which triggers the turnout solenoid (like flipping a switch) with power coming from the CDU.

*.... but there is no device that you can buy off the shelf that will do all what you want to do.
CORRECTION. Maybe there is! I overlooked Train Tronics. They make a automatic revesing unit and a automatic turnout control. I don't know anything about them like what it doesn't include or how to hook it up, but it comes with instructions. About $80 for both.



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