Trains.com

Installing Rectifier Disks in Transformers

10579 views
25 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    January 2006
  • 193 posts
Installing Rectifier Disks in Transformers
Posted by gottcent on Sunday, February 10, 2013 10:05 AM

I generally find it easy to remove old rectifier disks from the whistle control assemblies in postwar transformers, but when it comes to installing a new one, I have trouble with the speed nut. They're usually very hard to re-insert on their post. I have tried forcing them with a nut driver wide enough to provide even pressure, but that doesn't always provide enough force. I've occasionally resorted to tapping the nut driver with a hammer, but I'm afraid of jarring something else loose in the transformer, not to mention damaging the handle of the nut driver. Any suggestions on an easier way to do this?

John Gottcent

  • Member since
    August 2008
  • From: Virginia
  • 544 posts
Posted by TRAINCAT on Sunday, February 10, 2013 2:50 PM

Don't bother with old outdated technology. Buy a new diode and replace the old rectifiers. They work far better than the old way. People are selling them on Ebay and Davis Lyons in Burlington NC sells them.

http://lioneltransformer.com/

Roger

  • Member since
    October 2011
  • 969 posts
Posted by TrainLarry on Sunday, February 10, 2013 9:09 PM

  You need to use a nut driver just a little larger than the rectifier pin diameter to push the speednut back in place. Too large a nut driver will put the force on the outer edges of the speednut, and you will have problems pressing it back on. Use something to back up the rear (head) of the pin while you are pressing the speednut into place from the front, and you should have no problem getting it back on, or damaging the transformer. No hammering should ever be needed.

Larry

  • Member since
    April 2010
  • 269 posts
Posted by silentman on Sunday, February 10, 2013 11:46 PM

trainrat

Don't bother with old outdated technology. Buy a new diode and replace the old rectifiers. They work far better than the old way. People are selling them on Ebay and Davis Lyons in Burlington NC sells them.

http://lioneltransformer.com/

Roger

Is there much to switching the old rectifiers out with  a new diode?

  • Member since
    December 2001
  • From: Austin, TX
  • 10,096 posts
Posted by lionelsoni on Monday, February 11, 2013 9:11 AM

They may be longer-lived, but most silicon diodes are electrically very slightly inferior to the original copper-oxide ones, having a greater forward voltage drop.  You're not likely to notice the difference; but the more-modern silicon is not likely to be superior to copper-oxide that has not failed.

Electronics technology, like any art, should be judged on its merits, not its age.

Bob Nelson

  • Member since
    August 2008
  • From: Virginia
  • 544 posts
Posted by TRAINCAT on Monday, February 11, 2013 10:57 AM

Bob,

I acknowledge the fact that you have more experience than probably anyone here. But I disagree about your summary of the rectifier disks. The reason we replace the old ones with new technology is because they work far better than the old Lionel disks and blow the whistles sharply and every time. I have them in all 6 of my post war transformers and would not want the old ones back.

Regards,

Roger

  • Member since
    April 2010
  • 269 posts
Posted by silentman on Monday, February 11, 2013 12:08 PM
Any chance of a quick picture or tutorial on how to replace a disk rectifier with a diode in a ZW? Will this help with the "sweet spot" I too am familiar with?
KRM
  • Member since
    January 2011
  • From: North Bluff above Marseilles IL
  • 6,506 posts
Posted by KRM on Monday, February 11, 2013 12:30 PM

trainrat

Bob,

I acknowledge the fact that you have more experience than probably anyone here. But I disagree about your summary of the rectifier disks. The reason we replace the old ones with new technology is because they work far better than the old Lionel disks and blow the whistles sharply and every time. I have them in all 6 of my post war transformers and would not want the old ones back.

Regards,

Roger

 Roger I could not agree more with your statement. I have had mine replaced by a person from Shorewood IL. Ken Koehler who has been rebuilding and restoring Lionel transformers for more than 30 years and in MHO is a expert on them.   He hands down recommends the diode. Here is a quote from his web site. " a diode will be installed which is a MUST for operating electronic trains!" I can tell you since the diodes have been installed in my post war transformers my modern units work just as they should and they did not with the rectifier disks.

You can contact him here.

http://www.lioneltransformers.com./

Joined 1-21-2011    TCA 13-68614

Kev, From The North Bluff Above Marseilles IL. Whistling

 

  • Member since
    August 2008
  • From: Virginia
  • 544 posts
Posted by TRAINCAT on Monday, February 11, 2013 12:47 PM

There are some pics and maybe videos on doing the ZW in the web if you look. I think the ZW(only one I have not owned) takes 2 of them. Try    http://lioneltransformer.com./diodes. Davis has them.

Here is a video of installation-http://www.youtube.com/watch?v=4kG5SIv9K2g

Roger

  • Member since
    April 2010
  • 269 posts
Posted by silentman on Monday, February 11, 2013 1:35 PM
Thanks a bunch!!
  • Member since
    August 2008
  • From: Virginia
  • 544 posts
Posted by TRAINCAT on Monday, February 11, 2013 1:45 PM

You are most welcome my friend.

Roger

  • Member since
    December 2001
  • From: Austin, TX
  • 10,096 posts
Posted by lionelsoni on Monday, February 11, 2013 3:08 PM

Roger, I was responding to your comment, "Don't bother with old outdated technology...."  Surely those of us who value old toy trains should appreciate that "newer is better" does not always hold true.  In this case, it would indeed be rational to replace old with new--if new were shown to be better.  I have conceded that it is convenient and practical to replace defective copper-oxide rectifiers by silicon.  But my understanding of the electronics of this matter still leaves me thinking that an undeteriorated copper-oxide rectifier is at least as good in this application as silicon.

I found this interesting paragraph on Wikipedia, concerning the advantages of metal rectifiers at low voltages:

"Metal rectifiers have been replaced by silicon diodes in most devices, however there are certain applications where the replacement of metal rectifiers with silicon units has proven impractical. These are mostly in electroplating, aluminium smelting and similar high-current low-voltage industrial applications, where the lower forward voltage drop of metal rectifiers is more important than their reverse breakdown voltage."

Bob Nelson

KRM
  • Member since
    January 2011
  • From: North Bluff above Marseilles IL
  • 6,506 posts
Posted by KRM on Monday, February 11, 2013 8:03 PM

Seems some just got to have the last word. Right or wrong.  I wish I was so much smarter than the rest of the world that has lived so much more than me and I was so much smarter than the rest of us. At least in their minds.

"Metal rectifiers have been replaced by silicon diodes in most devices, however there are certain applications where the replacement of metal rectifiers with silicon units has proven impractical. These are mostly in electroplating, aluminium smelting and similar high-current low-voltage industrial applications, where the lower forward voltage drop of metal rectifiers is more important than their reverse breakdown voltage."

What does that have to do with toy trains?? argument for the sake of argument??

I am done here.

Joined 1-21-2011    TCA 13-68614

Kev, From The North Bluff Above Marseilles IL. Whistling

 

  • Member since
    April 2010
  • 269 posts
Posted by silentman on Monday, February 11, 2013 8:28 PM
KRM...Do you know how far Shorewood is from Galesburg off hand?
  • Member since
    March 2009
  • From: Central Texas
  • 318 posts
Posted by Texas Pete on Tuesday, February 12, 2013 8:11 AM

KRM

<SNIP>

Was that really necessary?

Pete

"You can’t study the darkness by flooding it with light."  - Edward Abbey -

  • Member since
    November 2002
  • From: US
  • 192 posts
Posted by sulafool on Tuesday, February 12, 2013 11:37 AM

Lets see... you have a light bulb burn out and replace it with a new CFL bulb, then conclude that since it isn't dark anymore CFLs are better than incandescent bulbs?

I suggest that if you replaced the old copper disk with one of the new repros your horns and whistles would work just as well as a silicon diode. I used to use the silicon diodes but have reverted to the disk type because I could see no advantage in the "new technology", and in most cases it's much easier to replace the disk.

  • Member since
    March 2002
  • From: Tucson
  • 336 posts
Posted by webenda on Tuesday, February 12, 2013 11:52 AM
KRM

I wish I was so much smarter than the rest of the world...

"Metal rectifiers..."

What does that have to do with toy trains??

KRM,

Bob's contribution explains that metal rectifiers are still a viable choice for many applications. It is "OK" to replace metal rectifiers in a toy train transformer with a new metal rectifier.

 ..........Wayne..........

  • Member since
    March 2002
  • From: Tucson
  • 336 posts
Posted by webenda on Tuesday, February 12, 2013 12:26 PM
Push Nut Tool photo PushNutTool_zps40cd7b0c.jpg

There are special tools for working with push nuts.

I think Larry's nut driver suggestion is superior to the special tool because; 1, you can get a bunch of nut drivers for the cost of a speed nut tool and 2, the nut driver has more than one function.

 ..........Wayne..........

  • Member since
    August 2008
  • From: Virginia
  • 544 posts
Posted by TRAINCAT on Tuesday, February 12, 2013 3:00 PM

"It is "OK" to replace metal rectifiers in a toy train transformer with a new metal rectifier.

The new diodes work far superior to the old Lionel disks and the 1950 technology. Out of the 7 transformers I have here, none of them blew the whistle as well and consistently as the new diodes do. I have done the install for several people and they love it too. If you like old technology and you feel better, keep your old disks. 

Roger

  • Member since
    July 2003
  • From: Wisconsin
  • 2,877 posts
Posted by Bob Keller on Tuesday, February 12, 2013 3:29 PM

Guys, there are many paths to achieving the same goal in the toy train world. I think that everyone has pretty much staked out their positions as "old-style but works" and "new-style but works." I don't think this is worth a general disagreement and getting the thread locked because of intemperate language or behavior.

I'm just sayin ...

Bob Keller

  • Member since
    April 2007
  • From: MICH
  • 8,153 posts
Posted by sir james I on Tuesday, February 12, 2013 8:02 PM

I have had OLD discs fail and have had NEW diodes fail, so use what you like they both work...S.J.

"IT's GOOD TO BE THE KING",by Mel Brooks 

  Charter Member- Tardis Train Crew (TTC)   - Detroit3railers-  Detroit Historical society Glancy Modular trains- Charter member BTTS

  • Member since
    March 2002
  • From: Tucson
  • 336 posts
Posted by webenda on Tuesday, February 12, 2013 9:48 PM
I believe you Roger (on all counts.) Unlike email, these posts can be edited after posting and I have done so.

 ..........Wayne..........

  • Member since
    April 2010
  • 269 posts
Posted by silentman on Tuesday, February 12, 2013 10:22 PM
I appreciate both sides of an issue such as this. Helps me make a decision that suits my needs as a newer toy train enthusiast. Keep up the opinions.
  • Member since
    February 2013
  • 2 posts
Posted by TheDude23112 on Wednesday, February 13, 2013 6:33 PM

Try this for installing new diodes:

http://www.tranz4mr.com/site/ZW_Whistle_Diodes.html

  • Member since
    April 2010
  • 269 posts
Posted by silentman on Wednesday, February 13, 2013 11:54 PM
Printed that the other day in anticipation for the arrival of two diodes on friday! Thanks Dude!
  • Member since
    April 2010
  • 269 posts
Posted by silentman on Saturday, February 16, 2013 1:22 PM

Installed the diode today....Wow, big difference. Thanks again!

Join our Community!

Our community is FREE to join. To participate you must either login or register for an account.

Search the Community

FREE EMAIL NEWSLETTER

Get the Classic Toy Trains newsletter delivered to your inbox twice a month