New Server: Thank you for your patience. We moved to our new server. Everything should be back to normal EXCEPT for the Gallery. We will have that restored shortly and will make an announcement. If you see something that is not working please report it here: Server Upgrade.

!!

Not Registered?

Welcome!  Please register to view all of the new posts and forum boards - some of which are hidden to guests.  After registering and gaining 10 posts you will be able to sell and buy items on our N'porium.

If you have any problems registering, then please check your spam filter before emailing us.  Hotmail users seem to find their emails in the Junk folder.


Thanks for reading,
The NGF Staff.

Author Topic: Reversing polarity on a turntable.  (Read 221 times)

0 Members and 1 Guest are viewing this topic.

Offline Mash Can

  • Trade Count: (0)
  • Full Member
  • ***
  • N Gauge Society Number: 26106
  • Posts: 46
  • Country: gb
    • Awards
Reversing polarity on a turntable.
« on: December 06, 2018, 06:44:44 AM »
I have reached the point where I need to wire up a Peco turntable on my new layout, obviously as standard there is the issue of shorting when the table is turned. I have two redundant mono frog juicers and wondered if there was a way these could be used to reverse the polarity when the table is turned. I seem to remember seeing something about it a while back, but can't find anything at present.
Any help would be gratefully received, as anything other than basic wiring is still a mystery to me :doh:
My apologies in advance to the moderators if I am on the wrong board.

Offline ntpntpntp

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 2360
  • Country: gb
    • Awards
Re: Reversing polarity on a turntable.
« Reply #1 on: December 06, 2018, 07:09:30 AM »
I had a Peco turntable back in the 80s. I'm sure it had wiper contacts from the track down to a circular copper ring which was split in half. All that was needed was to orientate the table so the the split was aligned so that the polarity changed at 90 degrees from the entry track.

I suppose with DCC it's a bit more of a problem to maintain continuous power if you have a sound loco sitting on the table.  Two concentric continuous pickup rings would be needed rather than a single split ring, with an automatic reverse-loop module to swap polarity as required.
Nick.   2016 celebrating the 20th anniversary of "Königshafen" exhibition layout!

Offline Mash Can

  • Trade Count: (0)
  • Full Member
  • ***
  • N Gauge Society Number: 26106
  • Posts: 46
  • Country: gb
    • Awards
Re: Reversing polarity on a turntable.
« Reply #2 on: December 06, 2018, 07:22:52 AM »
I can see what you mean, I guess where a split ring is involved there is always going to be that small dead area.

Offline Bealman

  • Moderator
  • Trade Count: (0)
  • Full Member
  • ****
  • N Gauge Society Number: 23151
  • Posts: 14496
  • Country: au
  • Gender: Male
  • Whoops back we go
    • Awards
Re: Reversing polarity on a turntable.
« Reply #3 on: December 06, 2018, 07:27:29 AM »
There are many posts here about motorising a Peco turntable.

Please use the search function.  :thumbsup:
Vision over visibility. Bono, U2.

Offline Steven B

  • Trade Count: (+1)
  • Full Member
  • ***
  • N Gauge Society Number: 12107
  • 2mm Association Number: 4196
  • Posts: 516
  • Country: gb
    • NGS Yorkshire Area Group
    • Awards
Re: Reversing polarity on a turntable.
« Reply #4 on: December 06, 2018, 09:31:06 AM »
I don't think using two mono frog juicers would work; There's a good chance that they'd end up fighting each other.

You need an auto-reverse module (or dual frog juicer that can be configured as one).

Using an auto-reverse module also means that you could replace the Peco split ring with something more reliable; A proper slip ring connector or even just a 1/4" audio jack & socket should be better in the long run.

Offline Paul-H

  • Trade Count: (0)
  • Full Member
  • ***
  • N Gauge Society Number: 27678
  • Posts: 584
  • Country: gb
  • Gender: Male
    • Awards
Re: Reversing polarity on a turntable.
« Reply #5 on: December 06, 2018, 10:25:17 AM »
Hi

You don't need anything to connect the peco turntable to DCC.

There is a dead section were no contact is made, all tracks on one side of the dead section are wired the same as your main track and all the tracks on the other side of the dead section are wired the other way around.  I think there is a Brian Lambert guide on it if you Google his site.

That's how I did mine and it's fine

Paul
Please excuse any poor spelling, I am Dyslexic, just think yourself lucky if you can actually read what I typed.

All tiepin as bean spell chequed on mi Pea Sea

Offline Mash Can

  • Trade Count: (0)
  • Full Member
  • ***
  • N Gauge Society Number: 26106
  • Posts: 46
  • Country: gb
    • Awards
Re: Reversing polarity on a turntable.
« Reply #6 on: December 06, 2018, 02:11:04 PM »
I've found Brian Lambert's site and it looks to answer most of my questions. Strangely all the links I came across to his guides over the past couple of days didn't appear to be working.

I think I'll drop the juicer idea and use them on the two new unifrog points I've installed as they aren't prefect out of the packet and for now wire the turntable as Paul suggests.

Many thanks for taking the time to reply.

Brian


Offline jpendle

  • Trade Count: (0)
  • Full Member
  • ***
  • N Gauge Society Number: 23638
  • Posts: 560
  • Country: us
    • Awards
Re: Reversing polarity on a turntable.
« Reply #7 on: December 06, 2018, 02:23:25 PM »
Just to answer your original post.

Yes two mono frog juicers can be used to switch polarity on a turntable, one would be wired to each track.

Two mono juicers are the same as a dual juicer and both are electrically equivalent to a reversing module.

I wonder sometimes if people think a Hex Frog Juicer is something to do with black magic, or the computer at Unseen University, as opposed to a 6 output juicer module.

I used one Hex Juicer to control a reversing loop and to switch the polarity of the frogs on my two diamond crossings on my old layout. (DCC with Electrofrogs throughout)

I have never felt the need to use a juicer to protect against running wrong way into a set of points.

Regards,

John P

Online njee20

  • Trade Count: (+4)
  • Full Member
  • ***
  • N Gauge Society Number: 22598
  • Posts: 3997
  • Country: gb
    • Awards
Re: Reversing polarity on a turntable.
« Reply #8 on: December 06, 2018, 04:13:50 PM »
I have never felt the need to use a juicer to protect against running wrong way into a set of points.

I don't think anyone uses them specifically for that, do they? The train would still derail. Their principal use in pointwork is to supplement blade contact for electrical continuity, they simply reverse the polarity depending on which way the point is set. This is to aid smoother running through points and nothing to do with protection against running into a wrongly set point.

Offline jpendle

  • Trade Count: (0)
  • Full Member
  • ***
  • N Gauge Society Number: 23638
  • Posts: 560
  • Country: us
    • Awards
Re: Reversing polarity on a turntable.
« Reply #9 on: December 06, 2018, 05:52:30 PM »
I have never felt the need to use a juicer to protect against running wrong way into a set of points.

I don't think anyone uses them specifically for that, do they? The train would still derail. Their principal use in pointwork is to supplement blade contact for electrical continuity, they simply reverse the polarity depending on which way the point is set. This is to aid smoother running through points and nothing to do with protection against running into a wrongly set point.

Aaahh! it all becomes clear.

You see that explains why I never used Frog juicer on a point, because I'm using slow acting stall motors (Tortoise) and have removed the springs from my Peco points, as a result blade contact doesn't work at all. I have always used the switches on the Tortoise to switch the polarity of the frog, and because the spring is removed I don't get issues with the point blades switching frog polarity before the switch does it.

Regards,

John P

Online njee20

  • Trade Count: (+4)
  • Full Member
  • ***
  • N Gauge Society Number: 22598
  • Posts: 3997
  • Country: gb
    • Awards
Re: Reversing polarity on a turntable.
« Reply #10 on: December 06, 2018, 05:58:26 PM »
Yep, all a frog juicer (or Gaugemaster Autofrog, or microswitxh or anything else) is doing is the same thing as the polarity switch on the Tortoise.

Offline ntpntpntp

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 2360
  • Country: gb
    • Awards
Re: Reversing polarity on a turntable.
« Reply #11 on: December 06, 2018, 06:44:26 PM »
Yep, all a frog juicer (or Gaugemaster Autofrog, or microswitxh or anything else) is doing is the same thing as the polarity switch on the Tortoise.

Well kind of, I'm not comfortable with anything which relies on detecting a short circuit in order to work. Bad engineering in my book. I much prefer having the polarity switched intentionally by a changeover contact (and which will work on plain DC also).
Nick.   2016 celebrating the 20th anniversary of "Königshafen" exhibition layout!

Online njee20

  • Trade Count: (+4)
  • Full Member
  • ***
  • N Gauge Society Number: 22598
  • Posts: 3997
  • Country: gb
    • Awards
Re: Reversing polarity on a turntable.
« Reply #12 on: December 06, 2018, 08:48:32 PM »
Yes, as it was OT I wasn’t going to get into the semantics, net result is basically the same!

 

Please Support Us!
December Goal: £55.00
Due Date: Dec 31
Total Receipts: £120.00
Above Goal: £65.00
Site Currency: GBP
218% 
December Donations


Advertise Here