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Power for Atlas switch motors

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  • Member since
    December 2007
  • From: Gateway City
  • 1,593 posts
Power for Atlas switch motors
Posted by yankee flyer on Monday, February 4, 2008 10:47 AM

 Good morning

I am powering my Atlas dual coil turnout motors with an old toy train transformer with an output of 8--15 Volts. It does not say AC or DC. I have burned out switching motors because someone has laid something on the switches or they stuck. Either way the motors melt. Does anyone know how to limit the power or time of power going to the motors/ I thought I remembered some thing about a capacitor discharge circut or something. I want to keep it simple.

I apreeeciate it.

Lee

Over the mountains of the moon,

through the valley of shadows,

ride boldly ride, if you seek El Dorado

  • Member since
    September 2007
  • From: Charlotte, NC
  • 6,099 posts
Posted by Phoebe Vet on Monday, February 4, 2008 1:02 PM

A capacitive discharge circuit is a way of getting more short term current from a low current power supply.  The flash you use to take pictures has one.  That is the noise you hear when the flash is recycling.  The capacitor charges slowly, then when the circuit is triggered it discharges suddenly.

For your snap switches you just need to be sure that the power is only applied long enough to throw the switch.

If you feel the atlas wsitches are unreliable, then use SPDT switches and a momentary contact push button.  Set the switch to the desired switch position then push the button to apply the power and immediately release it.

Dave

Lackawanna Route of the Phoebe Snow

  • Member since
    November 2007
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Posted by BlueHillsCPR on Monday, February 4, 2008 1:02 PM

Hi Lee,

Yes the Capacitor Discharge Supply provides a quick zap of higher voltage to the twin coils operating the turnouts with a  nice snap yet not powering them long enough to fry the coil.

There are a number of plans available to build your own or you can buy them assembled as well I believe.  Here's a link to one you can build.

http://www.awrr.com/cdsupply.html

 

 

  • Member since
    December 2007
  • From: Gateway City
  • 1,593 posts
Posted by yankee flyer on Monday, February 4, 2008 2:04 PM

Thanks guys, and for the link Kevin. That sure looks like what I was looking for. I have little guys operating the lay out and I think the last motor that got fryed  was because someone laid their hand or something on the switch.

  

Lee

  • Member since
    November 2007
  • 1,089 posts
Posted by BlueHillsCPR on Monday, February 4, 2008 3:17 PM
 yankee flyer wrote:

Thanks guys, and for the link Kevin. That sure looks like what I was looking for. I have little guys operating the lay out and I think the last motor that got fryed  was because someone laid their hand or something on the switch.

  

Lee

Ahh the little guys.  I did something similar, (as a little guy) to one of my own turnout motors.

If you need any further assistance some of the guys here will be able to help out.  I'm going to take a stab at building that CD Supply I linked for you.  Maybe without the optional ready circuit though.  Have a good one!  Smile [:)]

  • Member since
    December 2007
  • From: Gateway City
  • 1,593 posts
Posted by yankee flyer on Monday, February 4, 2008 3:38 PM

Kevin

I checked with Radio shack and they had everything but the R2 390 ohm resister. It has been discontinued and they don't have anything to replace it. I could put two resisters in series and get close but I'm not sure how that would effect the output.

Lee

Who is the man in black?

  • Member since
    February 2001
  • From: Poconos, PA
  • 3,948 posts
Posted by TomDiehl on Monday, February 4, 2008 5:22 PM
 yankee flyer wrote:

Kevin

I checked with Radio shack and they had everything but the R2 390 ohm resister. It has been discontinued and they don't have anything to replace it. I could put two resisters in series and get close but I'm not sure how that would effect the output.

Lee

Who is the man in black?

Resistors in series simply add their resistance values together. If it adds up to 390 ohms, it should work as planned.

Smile, it makes people wonder what you're up to. Chief of Sanitation; Clowntown
  • Member since
    September 2007
  • From: Charlotte, NC
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Posted by Phoebe Vet on Monday, February 4, 2008 6:04 PM
 yankee flyer wrote:

Kevin

I checked with Radio shack and they had everything but the R2 390 ohm resister. It has been discontinued and they don't have anything to replace it. I could put two resisters in series and get close but I'm not sure how that would effect the output.

Lee

Who is the man in black?

http://www.gadgettom.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=RES-25-390&Category_Code=WA

Dave

Lackawanna Route of the Phoebe Snow

  • Member since
    November 2007
  • 1,089 posts
Posted by BlueHillsCPR on Monday, February 4, 2008 8:53 PM
 yankee flyer wrote:

Kevin

I checked with Radio shack and they had everything but the R2 390 ohm resister. It has been discontinued and they don't have anything to replace it. I could put two resisters in series and get close but I'm not sure how that would effect the output.

Lee

Who is the man in black?

As was mentioned, you can use two resistors combined to get the approximate resistance.  Resistance values in most circuits are somewhat arbitrary.  They can usually vary slightly without effecting the circuit drastically but it depends on the application.  I found a 390 Ohm resistor available at Mouser Electronics part #293-390-RC.

390 Ohm Resistor 

 

The man in black was Randall Flagg, known by many many names and either real or not, depending on ones personal beliefs.  It's just a quote from a Stephen King novel. "The Gunslinger".  Roland, the gunslinger rides the rails in his quest for the dark tower. Smile [:)]

 

  • Member since
    December 2007
  • From: Gateway City
  • 1,593 posts
Posted by yankee flyer on Monday, February 4, 2008 9:18 PM

Kevin

It's been a long time since I went to tech school so I would not know how much leway you have in that little resister' value. Nothing is simple anymore in E. Tec.

 I guess you recognise E.A. Poe

Thanks again

Lee

 

  • Member since
    November 2007
  • 1,089 posts
Posted by BlueHillsCPR on Monday, February 4, 2008 9:24 PM
 yankee flyer wrote:
Kevin

It's been a long time since I went to tech school so I would not know how much leway you have in that little resister' value. Nothing is simple anymore in E. Tec.

 I guess you recognise E.A. Poe

Thanks again

Lee

Lee,

I never had the luxury of going through E.E. training like a lot of guys here.  I had a great shop teacher for electronics in high school and continued to learn on my own. Like you I am not certain how much leeway there is in the values for this circuit.  Much better to have the actual part. Thumbs Up [tup]

Indeed I am familiar with Mr. Poe.  The Raven is probably my favorite.

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