Re: Scratch built diamonds
Vollrath, Don <dvollrath@...>
You did a hybrid of my 2) and 3) whereas your ‘buffer’ zone isolated the entire crossing and path occupancy permission control is somewhat obvious, even if manual by train engineers. Yes you can power the entire ‘isolated’ crossing via a PSX-AR. However the design of the frogs is still important to avoid dead spots or shorts.
Lee’s questions brought in the possibility of issues of using a frog juicer… a different product than the PSX-AR… or other brand A-R units for that matter… and workability with two separate CB power districts. Either of these have been demonstrated by others to be somewhat problematic depending on choices of other equipment.
From: WiringForDCC@... [mailto:WiringForDCC@...]
Sent: Monday, April 11, 2016 9:51 AM
Subject: RE: [WiringForDCC] Scratch built diamonds
In my diamonds which are 3 x 5 for 15 diamonds I have a 2 inch buffer around them. I then have a PSX A-R flipping power on the one side of each direction. The buffer is needed because if an engine is going East and West then an engine cannot be in the buffer zone for the North and South route. I can't recall a single instance of an issue with an engine coming in from each direction which would have caused the PSX A-R to flip out.
To add to the complexity, I had interchange tracks on 3 of the four sides connecting the two routes. I had a dedicated PSX A-R for the diamonds. I had a second PSX A-R that addressed flipping the power on the interchange track that required it.
The simple answer is “Yes”. You may have issues with a frog juicer and/or auto-reverser if the entrance and exit paths cross between two different boosters or different circuit breaker limited power districts. Difficult to explain but multiple incident reports of just that. Might have something to do with using single or double or hex juicers, or older units vs newer ‘improved’ designs.
There are a few options: 1) use a crossing with a better design that uses smaller dead frogs. 2) Wire the entire crossing from only one power district and a PSX A-R unit powered from that district. Yes, a train traveling in the other path will momentarily connect the two districts together. 3) Power the frog areas of the crossing via a DPDT relay triggered to select the proper district source and polarity from approaching train (track occupancy) sensors, or train dispatcher controlled permission operation.
All, I am referencing David Klemm's scratch built diamonds (http://www.wiringfordcc.com/track_2.htm) he made for his DCC