Wiring a swing gate?


Jim Betz
 

Hi,

  Very soon I'll be laying track across two swing gates.  Both gates are two 
levels of track.  When a gate is open I want the track on the gate - and the
approaches on either side - to be dead (no track power).

  What method for turning the power on and off do you recommend?  Or
better yet "have you used"?

  My thought is to use a micro switch that goes to a relay that cuts the
power/restores it.  I'm thinking the kind of switch that would be used for
a refrigerator door or some other such application.  These usually have
a short arm with a roller on it and are activated by the pressure that
moves the arm.  These are known as "limit switches".

        https://www.amazon.com/TEMCo-Micro-Switch-Roller-Action/dp/B0163B7W5A

  I'm open to other solutions/suggestions.
                                                                            - Jim in the PNW


Tom O'Hara
 

Hi..
That is basically what I have used. I also decided to route the power so it cut off the tracks on both sides of the opening for 5 feet or so, which required (in my case) two switches. There may be a better way, but this was primitive and worked. All my stay alive circuits were adjusted to stop within that distance. Some people rig some form of mechanical stop to keep their engines from taking the Great Fall, but I felt safe without that. I'd be interested in hearing suggestions for a better method if there is one for the next railroad I build.

....Tom

On Wed, Jun 8, 2022 at 7:21 AM Jim Betz <jimbetz@...> wrote:
Hi,

  Very soon I'll be laying track across two swing gates.  Both gates are two 
levels of track.  When a gate is open I want the track on the gate - and the
approaches on either side - to be dead (no track power).

  What method for turning the power on and off do you recommend?  Or
better yet "have you used"?

  My thought is to use a micro switch that goes to a relay that cuts the
power/restores it.  I'm thinking the kind of switch that would be used for
a refrigerator door or some other such application.  These usually have
a short arm with a roller on it and are activated by the pressure that
moves the arm.  These are known as "limit switches".

        https://www.amazon.com/TEMCo-Micro-Switch-Roller-Action/dp/B0163B7W5A

  I'm open to other solutions/suggestions.
                                                                            - Jim in the PNW


Allan AE2V
 

Hi Jim,

I've seen lift bridges done a couple of different ways.  I don't know that there is any particular better way than any other.  I'd worry about finding a good way to make sure that the rails on your bridge reliably line up each time.

You can get "big" micro switches that can handle the track current and you don't necessarily need the relay.  But maybe you might want to drive some signals, too.  So you would need a relay or some other things to accomplish doing this as well.

The main electrical thing to worry about is cutting the power far enough back from the open bridge that a train with momentum doesn't careen into the open abyss.  Also, you have to worry about locomotives with stay alive circuits.  If you cut the power, these locomotives won't stop.

In the early days of DCC, there was DCC braking.  I haven't heard this mentioned in a LONG time.  I don't know if decoders made today support it.  As I recall, you used a relay to put a brake signal on the track instead of the normal DCC track power/signal.

Good luck

Allan Gartner
Wiring for DCC


David McBrayer
 

Jim, 
Using a “limit switch” to drive a relay is an excellent idea.  My suggestion is use a low AC voltage in the control circuit.  Note the current ratings on the switch you showed in the link.  
The reason for the much lower current rating with DC voltage is caused by arcing when the contacts open.  Initially the switch will “work” very well, but eventually the switch will become intermittent, and then fail.  Using a low AC voltage in the control circuit slows the degradation of the switch contacts immensely; to many years out.   An inexpensive wall wart transformer would be a great power supply. 

—Dave McBrayer 
Auburn, CA 
——————

On Jun 8, 2022, at 07:21, Jim Betz <jimbetz@...> wrote:

Hi,
  Very soon I'll be laying track across two swing gates.  Both gates are two 
levels of track.  When a gate is open I want the track on the gate - and the
approaches on either side - to be dead (no track power).

  What method for turning the power on and off do you recommend?  Or
better yet "have you used"?

  My thought is to use a micro switch that goes to a relay that cuts the
power/restores it.  I'm thinking the kind of switch that would be used for
a refrigerator door or some other such application.  These usually have
a short arm with a roller on it and are activated by the pressure that
moves the arm.  These are known as "limit switches".

        https://www.amazon.com/TEMCo-Micro-Switch-Roller-Action/dp/B0163B7W5A

  I'm open to other solutions/suggestions.
                                                                            - Jim in the PNW

--
Dave McBrayer
Auburn, CA


whmvd
 

Jim,

Dead track is all very well, but the day you install a keep-alive in a loco you find you've shot yourself in the foot. Not only will it just carry on (how long will depend on the size of the keep-alive), but you will also find yourself with no control.

If you have detection, sending estop to those trains that shouldn't do what they are about to do is, for me, really the only way to go.

Wouter


On Wed, 8 Jun 2022 at 15:21, Jim Betz <jimbetz@...> wrote:
Hi,

  Very soon I'll be laying track across two swing gates.  Both gates are two 
levels of track.  When a gate is open I want the track on the gate - and the
approaches on either side - to be dead (no track power).

  What method for turning the power on and off do you recommend?  Or
better yet "have you used"?

  My thought is to use a micro switch that goes to a relay that cuts the
power/restores it.  I'm thinking the kind of switch that would be used for
a refrigerator door or some other such application.  These usually have
a short arm with a roller on it and are activated by the pressure that
moves the arm.  These are known as "limit switches".

        https://www.amazon.com/TEMCo-Micro-Switch-Roller-Action/dp/B0163B7W5A

  I'm open to other solutions/suggestions.
                                                                            - Jim in the PNW


Jim Betz
 

Wouter,

  I know all about keep alives - and install them on ALL of my locomotives..  I'm not
worried - the dead track will be almost a meter long and that will stop any train at
any speed with any number of MU'ed locos (however it will be rare to ever see
more than one loco on a train on my layout).  And yes - I also know about the
loss of control while the loco is running only on the keep alive.

Dave McBrayer,

  I'm not sure I understand your caution about the power thru the limit switch.  I
understand they can go bad - but the number of times these will make/break is
very low.  Remember - I am thinking I will use one limit switch per swing gate
which will "re-wire" both layers ... cause the track on the gate and 3 feet in 
either direction to go dead when the gate is open.

Ron Merrill/all,

  My -swing- gates are already done ... with the exception of the track going
across them.  They are very positive in terms of going back to the exact
same place every time they are closed ... so no problems with the track
not lining up perfectly.  In fact, it is my intent to run the track right across
the "gaps" (perhaps better called "joints"), spike it all down, and then cut
the rails with a Dremel.  Yes, these gates are that good/that dimensionally
stable and return to exactly the same position every time.

                                                      ****

  No one has ... yet ... suggested a method of killing the track power other
than the limit switch and relay(s).  Are there no other methods?  Or none
better?
                                                                                            - Jim in the PNW


Tom O'Hara
 

I used a limit roller switch on one rail to turn off the power when it was up. It worked for 8-10 years without a hitch. No relay required, since the switch was over 2 A, and the engines didn't draw that much power. If I had used old open-frame motors, perhaps I would have needed a relay. As far as alignment, I attached a table leaf alignment pin (wooden) that came down into a nylon sleeve. I carefully filled an oversized hole in the lower receiver with enough epoxy along the outside, put the sleeve on the pin, lowered it down to where the epoxy filled the area around the sleeve and let it set up. Careful with the epoxy. Always lined up at the correct height, based on getting the alignment correct before epoxying. A toybox lift spring (there are other possibilities) at the other end would hold it up at about a 70 degree angle from horizontal on a bridge that was about 30" long. 

Maybe a new way next time, and maybe the same.

...Tom

On Wed, Jun 8, 2022 at 4:42 PM Jim Betz <jimbetz@...> wrote:
Wouter,

  I know all about keep alives - and install them on ALL of my locomotives..  I'm not
worried - the dead track will be almost a meter long and that will stop any train at
any speed with any number of MU'ed locos (however it will be rare to ever see
more than one loco on a train on my layout).  And yes - I also know about the
loss of control while the loco is running only on the keep alive.

Dave McBrayer,

  I'm not sure I understand your caution about the power thru the limit switch.  I
understand they can go bad - but the number of times these will make/break is
very low.  Remember - I am thinking I will use one limit switch per swing gate
which will "re-wire" both layers ... cause the track on the gate and 3 feet in 
either direction to go dead when the gate is open.

Ron Merrill/all,

  My -swing- gates are already done ... with the exception of the track going
across them.  They are very positive in terms of going back to the exact
same place every time they are closed ... so no problems with the track
not lining up perfectly.  In fact, it is my intent to run the track right across
the "gaps" (perhaps better called "joints"), spike it all down, and then cut
the rails with a Dremel.  Yes, these gates are that good/that dimensionally
stable and return to exactly the same position every time.

                                                      ****

  No one has ... yet ... suggested a method of killing the track power other
than the limit switch and relay(s).  Are there no other methods?  Or none
better?
                                                                                            - Jim in the PNW


David McBrayer
 

Jim, 
Your comment to Wouter re Keep Alive’s leads me to believe you use DCC to run your trains and not DC.  The DC current concern becomes a non-issue.  Where you gap your track, The relay becomes important if you gap both rails of your track.  My preference, when isolating track, is to gap both rails.  I then have confidence that ‘dead track’ is truly dead and not half-dead.   

Dave McBrayer 
Auburn, CA
——————

On Jun 8, 2022, at 16:42, Jim Betz <jimbetz@...> wrote:

Wouter,

  I know all about keep alives - and install them on ALL of my locomotives..  I'm not
worried - the dead track will be almost a meter long and that will stop any train at
any speed with any number of MU'ed locos (however it will be rare to ever see
more than one loco on a train on my layout).  And yes - I also know about the
loss of control while the loco is running only on the keep alive.

Dave McBrayer,

  I'm not sure I understand your caution about the power thru the limit switch.  I
understand they can go bad - but the number of times these will make/break is
very low.  Remember - I am thinking I will use one limit switch per swing gate
which will "re-wire" both layers ... cause the track on the gate and 3 feet in 
either direction to go dead when the gate is open.

Ron Merrill/all,

  My -swing- gates are already done ... with the exception of the track going
across them.  They are very positive in terms of going back to the exact
same place every time they are closed ... so no problems with the track
not lining up perfectly.  In fact, it is my intent to run the track right across
the "gaps" (perhaps better called "joints"), spike it all down, and then cut
the rails with a Dremel.  Yes, these gates are that good/that dimensionally
stable and return to exactly the same position every time.

                                                      ****

  No one has ... yet ... suggested a method of killing the track power other
than the limit switch and relay(s).  Are there no other methods?  Or none
better?
                                                                                            - Jim in the PNW

--
Dave McBrayer
Auburn, CA


Jim Betz
 

Dave,

  Yes - DCC.  I'm not even retaining the ability to run DC.  Yes, I always gap both rails 
when doing any "blocks".  I also use PSX circuit breakers between the booster and
the track for all track.  
  As I said before - my current thinking is to use one limit switch per gate with that
limit switch controling relay(s) that cut/make the actual track power (DCC).

  Since I'm not getting a lot of alternative suggestions I'll probably go with the limit
switch and relays.  Thanks guys - it's always good to run ideas past a group with
prior experience on the topic.  I'll post again after I've got it working to let you
know how it's going.
                                                                                                      - Jim in the PNW


Tim Bowser
 

I'm not able to locate a part # at this time, but there are fairly high-current push buttons.  I'm thinking of three closets at my (new-to-me) home, that turn on 115VAC lights when the door is opened.  Basically, plunger switch mounted in the door frame.

Tim B.


scott hurley
 

This topic most helpful as I am installing a swing gate as we speak. I also was thinking of plunger switch but need to wire it so providing power while closed rather than the normal powered while open such as with an alarm

On Thu, Jun 9, 2022 at 11:22 AM Tim Bowser <striker.tech@...> wrote:
I'm not able to locate a part # at this time, but there are fairly high-current push buttons.  I'm thinking of three closets at my (new-to-me) home, that turn on 115VAC lights when the door is opened.  Basically, plunger switch mounted in the door frame.

Tim B.

--

Scott