Wiring 2 facing points for on \ off track power?

Basic electrical and electronics, such as DC/Analog control.
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centenary
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Wiring 2 facing points for on \ off track power?

Post by centenary »

I hope the picture below helps explain what I want to do. Locos are DCC powered, rail on track 10 will need suitably positioned isolation gaps. If I only had one point, I know how to wire the DCC Concepts IPA to turn off track power to a route. However, when I have 2 points one after the other where either one needs to turn off track power, Im stumped!

Locos will travel right to left on the line shown as 10. I want to wire my point motors, DCC Concepts IPAs, so that if either the points at 4 or 5 are set against the loco travelling right to left at 10, track power is turned off, bringing the loco to a halt before point 4.

For example, if point 4 is set to the lower divirging route, the power along track 10 will be off. If point 4 is set for straight ahead from 10 but point 5 is set against the track from 10, then power to the track is turned off so the loco stops before point 4.

Hope that explains it. Can anyone suggest how I wire the 2 IPAs to get my result?
Screenshot from 2024-04-12 00-35-00.png
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Bigmet
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Re: Wiring 2 facing points for on \ off track power?

Post by Bigmet »

My immediate reaction is 'you don't want to do that'. The essence of correct operation is first set the route for the train that is to be operated over it. Don't know your point motor, so cannot advise there, but since you have purchased them I would suggest asking the vendor for thoughts.

Even before going with DCC, the one location on my layouts where I have made use of track isolation by mechanical switching is for the lifting access section, to avoid a scale 100 yard plus plummet into a chasm. Wthdrawing the locking bolts for the lifting section cuts off layout track power supply.
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centenary
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Re: Wiring 2 facing points for on \ off track power?

Post by centenary »

Bigmet wrote: Fri Apr 12, 2024 10:30 am My immediate reaction is 'you don't want to do that'. The essence of correct operation is first set the route for the train that is to be operated over it. Don't know your point motor, so cannot advise there, but since you have purchased them I would suggest asking the vendor for thoughts.

Even before going with DCC, the one location on my layouts where I have made use of track isolation by mechanical switching is for the lifting access section, to avoid a scale 100 yard plus plummet into a chasm. Wthdrawing the locking bolts for the lifting section cuts off layout track power supply.
Yes, I appreciate track should always be set for correct running of locos etc. But sometimes, we can forget or be distracted resulting in locos causing a short or derailment by running into points set against the route.

As far as I can figure out, the DCC Concept IPA at position 5 needs to be able to turn off track power for route 10 even if IPA 4 is set to straight ahead. Similarly, track power for route 10 needs to be turned off when IPA 4 is not set for straight ahead on route 10, even if IPA 5 is.

The IPA's only need to provide \ cut power to one rail on route 10's isolated section as the other rail would take power from the bus.

Giving it further thought, a possible solution is to have 2 separate isolation sections on route 10 with each separately controlled by the different IPAs. But, I was hoping there'd be a way to interconnect the 2 IPAs and their internal switching to do this using just one isolation section.
Suzie
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Re: Wiring 2 facing points for on \ off track power?

Post by Suzie »

I am assuming that you are using IP digital motors (the only reference to DCC Concepts IPA is for Isopropyl Alcohol). This will work for analogue motors too.

So as I see it the wiring for each point motor should be as follows:-
1 - Top rail track feed.
2 - Bottom rail track feed.
3 and 6 - Frog feed (join together).
4 - Feed to track beyond frog at top rail polarity.
5 - Feed to track beyond frog at bottom rail polarity.

The connections to pins 1-3 are straightforward, it is the connections to 4 and 5 that isolate the piece of track not in use.
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centenary
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Re: Wiring 2 facing points for on \ off track power?

Post by centenary »

Suzie wrote: Sat Apr 13, 2024 10:41 pm I am assuming that you are using IP digital motors (the only reference to DCC Concepts IPA is for Isopropyl Alcohol). This will work for analogue motors too.

So as I see it the wiring for each point motor should be as follows:-
1 - Top rail track feed.
2 - Bottom rail track feed.
3 and 6 - Frog feed (join together).
4 - Feed to track beyond frog at top rail polarity.
5 - Feed to track beyond frog at bottom rail polarity.

The connections to pins 1-3 are straightforward, it is the connections to 4 and 5 that isolate the piece of track not in use.
Hi Suzie.

IPAs = IP Analog switch machines but as you say the above will work for both IPD's and A's, thank you for the wiring advice.

Im not clear about connections 3 and 6 though. Does this mean literally, join frog wires from both points together then from this add further wires one goes to terminal 3 on one point motor with the other to terminal 6 on the other point motor?

Cheers
Suzie
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Re: Wiring 2 facing points for on \ off track power?

Post by Suzie »

Connect both 3 and 6 to the frog of the point that the motor drives.
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