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Voltage for walthers cantilevers LED's

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  • Member since
    February 2001
  • From: Poconos, PA
  • 3,948 posts
Posted by TomDiehl on Wednesday, August 19, 2009 8:14 PM

Animal

TomDiehl

Usually, Wlathers is good about including instructions with their products. What did they say about the hookup?

Since it's designed to work with their Crossing Signal Controller, why reinvent the wheel? The full detection and flashing circuit is in a single module:

http://www.walthers.com/exec/productinfo/933-2307

It's currently on sale.

 

because im using this in conjunction with a boomgate system, so im using the logicrail circuit so i'll need resistors to run it of 12v

If you can't find your instructions that came with the signals or they don't give this info, you can find out what's needed with an ohm meter and a simple device I made:

To find the resistance of an LED with an ohm meter, set the meter to the ohms function, lowest range. Touch the ends of the leads together and zero the meter (if it has such a provision), or make note of the reading if there's no ohms zero adjust. You'll have to refer to you meter's instructions as the method of doing this varies from one meter to the next. Next, touch the leads to the leads of the LED and turn the range of the meter up (stepping slowly) until you get a reading. If you get no reading, retrun the meter to the lowest range and reverse the leads (polarity). Step up the range again, you should get a reading. An LED, like any diode, will conduct in one direction only, which is why you may have to reverse the leads to get a reading. The reading, minus the reading you recorded when zeroing the meter, is the forward resistance of the LED.

I have a very simple device to determine the forward voltage of an LED. It's made with two battery holders (I used AA size, but any 1.5 volt battery will work), three clip leads and wire to attach them. connect a short wire to connect the two battery holders in series (+ of one to - of the other) and also connect a short lead from this point to one of the clips. Connect the other two clpis to the other two end terminals, install batteries, and the device is complete. To use, connect the center lead and one of the other leads to the LED. If it doesn't light, reverse polarity. If it lights brightly, it's a 1.5 volt LED. If it lights dimmly, connect the leads from the outside of the battery holders to the LED. If it lights brightly, it's a 3 volt LED. Now you've determined the forward voltage.

Once you know resistance and voltage, divide voltage by resistance and you have amperage.

Smile, it makes people wonder what you're up to. Chief of Sanitation; Clowntown
  • Member since
    May 2008
  • 60 posts
Posted by Animal on Wednesday, August 19, 2009 7:04 PM

TomDiehl

Usually, Wlathers is good about including instructions with their products. What did they say about the hookup?

Since it's designed to work with their Crossing Signal Controller, why reinvent the wheel? The full detection and flashing circuit is in a single module:

http://www.walthers.com/exec/productinfo/933-2307

It's currently on sale.

 

 

because im using this in conjunction with a boomgate system, so im using the logicrail circuit so i'll need resistors to run it of 12v

  • Member since
    February 2001
  • From: Poconos, PA
  • 3,948 posts
Posted by TomDiehl on Wednesday, August 19, 2009 7:57 AM

Usually, Wlathers is good about including instructions with their products. What did they say about the hookup?

Since it's designed to work with their Crossing Signal Controller, why reinvent the wheel? The full detection and flashing circuit is in a single module:

http://www.walthers.com/exec/productinfo/933-2307

It's currently on sale.

Smile, it makes people wonder what you're up to. Chief of Sanitation; Clowntown
  • Member since
    December 2001
  • From: Pennsylvania
  • 709 posts
Posted by nedthomas on Wednesday, August 19, 2009 6:43 AM

Using my homemade crossing circuit at 10 volts DC I found 4.7K ohms works fine. At 12 volts the 4.7K should be OK or go to 5.6K. Install the resistor in series with the black lead.

  • Member since
    May 2008
  • 60 posts
Voltage for walthers cantilevers LED's
Posted by Animal on Tuesday, August 18, 2009 10:47 PM

 Im chasing the LED voltages and milliamps for the Walthers Modern Cantilever grade crossing signals.

And if possible whats the required resistors for these to run of a 12VDC power supply.

 

Thanks

Dom

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