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Over the last few months I have been converting over anything light-wise I can around the house to LED's, like many others. This includes screw in bulbs and fluorescents, among other things. So a short while back I decided to update my fleet of venerable old 022 switches to the 21st century and I ordered the necessary LED bulbs from Town and Country Hobbies.

After I converted the first few, I powered them up, and guess what? No joy with the red/green LED's on the controllers. Only the lantern LED's on the switch machine would work. So I checked the wiring diagram and discovered the problem. I power my switches with +16 VDC power, and the way they are wired means that the switch LED's get +ve to the base of the bulbs, BUT the controller LED's get -ve to the base of the bulbs, and consequently won't work. And I can't see any easy way to change this. So if you use DC power you will only be able to use LED's in the switches, or the controllers, not both, depending on the polarity of the power connected to the aux power plug. AC power would not have this problem.

Has anyone else had this problem? Any fix been found?

Thanks,

Rod

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Rod, the HO folks use bridge rectifiers in this manner all the time to light LED's regardless of track polarity.  The only issue is you have to have the LED on the output of the bridge totally isolated.  It really will work.   See the attached diagram and trace the current flow.

 

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  • mceclip0
Last edited by gunrunnerjohn

Ok John, Stan and others, thanks for the input. I see now how the bridge rectifier would work to solve the problem. I am not real excited about taking apart some 30 controllers though to do the fix. So maybe I'll go with the bi-polar bulbs per Stan's link at 4 bucks a pop. Or maybe I'll reverse the polarity of my +16VDC supply and run with LED's on the red/green controller bulbs and live with good old incandescents on the switch machines. Hhhmmmm.....

Rod

Perhaps another option is to find an AC output brick/wall-wart to power your switches.  Then you can use the less expensive LEDs in both controllers and switch machines.   A suitable AC source ought to be less out-of-pocket than $120 (30 switches x $4).

If the reason you were using DC was for other layout accessories, you can get an AC-to-DC converter module on eBay for about $5.

 

Last edited by stan2004
stan2004 posted:

Perhaps another option is to find an AC output brick/wall-wart to power your switches.  Then you can use the less expensive LEDs in both controllers and switch machines.   A suitable AC source ought to be less out-of-pocket than $120 (30 switches x $4).

If the reason you were using DC was for other layout accessories, you can get an AC-to-DC converter module on eBay for about $5.

 

Thanks for the suggestions. I have powered my 022's with DC for about 20 years now, because they just seem to work smoother with no chatter, and no wheel sparking at the non-derailing rail. I custom built a  power supply some years back to provide the necessary 15 amps or so of power ((.15 + .25) amps per switch x 30 switches + spare), so I am not about to change that philosophy. As far as converting to the non-bias LED's, that would actually cost (30 switches x 2 bulbs per switch (red & green) x $4 per bulb) = $240. Not really a big deal when you figure it would be a one time only cost. I may have to bite the bullet and just do it!

Rod

oldtimer posted:
The "cree" led bulbs depicted previously arent worth a dam in switches or contollers. Even with 16V they hardly light up. I know from experience and they wont take them back. Stay away from that vender.. JMHO bob

Very interesting comment. Anyone else had this problem with the "cree" LED's? I am certainly not keen on dropping $240 to find out they are not worth a darn. Old school bulbs are looking better every minute.

Thanks oldtimer,

Rod

Rod,

   In reality you do not need to do anything but purchase the correct LED Bulbs.  Go into the search mode and find the thread where years ago we talked about replacing all the standard bulbs in the  022, 072 and old 711 switches with LED's  I can not remember the exact numbers on the LED's, however they are LED's with flat heads.  These LED's work perfectly in both the track side fixture and the controllers.  It is true some of the other different LED's have trouble in the controllers.  In the thread you will find the exact numbers for the different LED's and where we were purchasing them.

Pine Creek/Dave

 

Last edited by Pine Creek Railroad

I am surprised no one else has responded with comments about using these specific LEDs?

At $4 a pop, they should provide specs on brightness...and show side-by-side photos with the corresponding incandescent bulb at the same voltage. 

I was next going to suggest just waiting for another polarity-insensitive LED supplier to come along but glanced at their Patent and before my eyes glazed over I noticed a bridge rectifier front-and-center as their solution to the polarity issue. Google search also brings up a patent lawsuit against another LED supplier...so perhaps this is keeping others away.  

So if one has to pony up $8 (2 bulbs) for a traditional controller, I wonder if someone makes a replacement controller that uses LEDs?  For every thread about replacing controller lamps with LEDs, it seems there's one asking about replacing the bulky controller assembly itself with a compact momentary toggle.  It's amusing how a "modern" controller might internally use a compact momentary toggle while retaining the traditional exterior look-and-feel!

mth controller

 

 

 

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  • mth controller
Last edited by stan2004

It should be fairly easy to build a replacement switch controller with LED's and the spring-loaded center off toggle for the switch.  Of course, as with all these things, making it cost effective is a whole different ballgame.  You'd have to have a significant quantity to justify the enclosure tooling costs, usually the killer on something like this.

gunrunnerjohn posted:

It should be fairly easy to build a replacement switch controller with LED's and the spring-loaded center off toggle for the switch.  Of course, as with all these things, making it cost effective is a whole different ballgame.  You'd have to have a significant quantity to justify the enclosure tooling costs, usually the killer on something like this.

Would this be an application for a 3d printer?

Rod

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