Lenz Braking Modules for alternating siding

D

Derailed

Registered
12 Nov 2019
21
Lansing, KS
Hello,
I upgraded my control system to NCE DCC and am installing Zimo decoders in all my locos. I want to be able to run 3 or more trains on one mainline loop with a station siding WITHOUT using a computer. I am currently using LGBs EPL system to do this but that cuts the power to the trains at the station. I have the Semaphore control power to both track block through the entrance point EPL drive. So when the signal is red, there is no power going to either track block. When the signal is green, there is power to the track that the turnout points are directed. The train trips a relay and switches the turnout behind it to the other track.

I see the Lenz BM1, 2 and 3 series will automatically stop and start trains in blocks using my LGB semaphores and EPL drives. That is good. I understand this blocking setup.

I want to be able to also alternate trains coming into a siding so that after one train departs the station, another train would pull in to the open track.
Right now, I can't figure out how to keep both trains in the station from pulling out at the same time. Does anyone have an idea how to accomplish this so that only one train will depart when the signal turns green?
 
Greg Elmassian

Greg Elmassian

Registered
8 Mar 2014
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San Diego
www.elmassian.com
I would go JMRI and automate that way. Once you have the occupancy sensors you should have complete flexibility to make any kind of program.

Trying to do it with relays and "hardware logic" will just be a pain and require rewiring when you want something different. Also I believe JMRI will give you a real-time display of the layout and occupancy.

Greg
 
D

Derailed

Registered
12 Nov 2019
21
Lansing, KS
Right, but I don't want to have to pull my computer out every time I want to run my trains. And I don't think I will change it too often. I am kind of stuck with what I can do track wise. At least until I decide to make a permanent layout. I need to stop moving every few years first.

I see the Mini-panel will do what I want but I need to buy a powerpro to make it work and so far, from what I have seen, if I want to change which engines I want to run, I have to reprogram it.
 
Greg Elmassian

Greg Elmassian

Registered
8 Mar 2014
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San Diego
www.elmassian.com
Yes, you are now using my argument... You can buy a Raspberry PI for cheap, put JMRI in it, put it on wifi, put it in a box and leave it on and forget about it. Side benefit, you have all kinds of fun stuff, infinite programmability, etc etc.

Also you can have wifi throttles using your phone, etc.

You have choices, but your first comment about using the mini-panel is right on target.

Greg
 
D

Derailed

Registered
12 Nov 2019
21
Lansing, KS
Being a "Geardo," I will likely move up to using a computer to run my trains one day. Right now, It is enough to learn the basic ins and outs of DCC. Baby steps.

I think I have it figured out.
Extend the two track blocks to the entire length of the station. Might even have to lengthen the station a few feet. Wire a BM1 on each block. This will default stop every train when it comes into the station no matter which track it comes into. Each block is now receiving asymmetric power.
Run a wire between the Semaphore EPL output and the Turnout EPL input. Wire the turnout EPL outputs to "power" the blocks. If the signal is Red, the BM1s will keep the trains at STOP. If the signal is Green, the track which the turnout is aimed at will receive a STOP(from the BM1) but a GO from the signal which provides a clean symmetric power to that block, which I understand overrides the STOP and will make that one train accelerate.
If anyone with experience with these believes I am in error, please let me know.
 
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D

Derailed

Registered
12 Nov 2019
21
Lansing, KS
With more reading I noticed the BM1s only handle 1A of continuous power. My PH10 is putting out up to 10A to the track. Are these only designed to be used with HO and smaller trains? If so, I suppose I would need to make my own version of the BM1 with larger capacity diodes? Am I over thinking this?
 
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Greg Elmassian

Greg Elmassian

Registered
8 Mar 2014
4,175
San Diego
www.elmassian.com
Not knowing the insides of the BM1, I suppose it is just a diode, and yes in that case you want a bigger diode, approximately double what your loco could draw would be a good idea.

Greg
 
idlemarvel

idlemarvel

Neither idle nor a marvel
13 Jul 2015
2,304
Ascot
My reading of the info on BM1 leads me to believe it will only work with Lenz decoders:
"The track voltage to the track section in front of the signal is directed via the BM1. If the signal is at 'Stop', the BM1 generates an asymmetry in the otherwise symmetrical, digital voltage. This is detected by Gold and Silver [Lenz] decoders as well as the new 10231-02 Standard [Lenz]."
EDIT: but this is from Lenz so maybe they are just promoting their decoders. This is just Automatic Braking Control (ABC) so other decoders can understand that
Also to confirm your finding about current (from the BM1 manual):
Maximum current carrying capacity
1.0 A continuous, 5A peak (approx. 5 sec)
 
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Greg Elmassian

Greg Elmassian

Registered
8 Mar 2014
4,175
San Diego
www.elmassian.com
The Zimo will do everything the Lenz decoder will and much more.

The asymmetry of the signal is making either the positive or negative transition of the DCC signal more or less:



I'm sure the specs for the voltage difference is somewhere, but it looks like 3 diode drops, i.e. approximately 2.1 volts but the spec calls out 2.8 it appears.

No idea what the tolerances are...

 
D

Derailed

Registered
12 Nov 2019
21
Lansing, KS
Since the BM1 is connected to track power, wouldn’t It need to handle a continuous 10A?
 
Greg Elmassian

Greg Elmassian

Registered
8 Mar 2014
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San Diego
www.elmassian.com
So, it needs to handle the current you locomotive draws.

Voltage is like water pressure
current is like volume flowing...

A locomotive "sees" whatever voltage is on the rails
but it only draws a certain amount of current, not everything that is available (that is known as a short circuit)

different locomotives draw different currents depending the the motor, voltage, load, grade, etc.

but to be safe, you would "design" your system to handle about double the max current you would draw.

So, how many locos would be in this section of track at one time, what kind of loco, how much load, etc.

As you might guess, you don't have all the answers there, so design for worst case is what an electrical engineer would tell you (and is telling you!).

Worst case at max load would be 20 amps... (since you said you have a 10 amp system, I know that system will put out 20 amps)

So, I doubt you will ever do that, so build it with 10 amp diodes, which will be expensive enough.

Greg
 
D

Derailed

Registered
12 Nov 2019
21
Lansing, KS
Thank you for that explanation. My largest loco is a LGB Mikado with several cars with LED lights. Only one train will be in the block at one time. This portion is pretty level.
 
Greg Elmassian

Greg Elmassian

Registered
8 Mar 2014
4,175
San Diego
www.elmassian.com
Of course, the likelihood you would need more than about 4 amps in your section is very slim, but using 10 amp diodes means a derailment there will most likely trip the breaker, not destroy you diodes.

But diodes are pretty cheap, so that is the way I would go. I try to make the foundation bulletproof, track and wiring is the foundation, if it is marginal, then reliability is out the window.

I did not research all the things Zimos can do with the asymmetric power, but I would guess there are lots of options.

Amazon, $6 for 20 ten amp diodes.


Greg
 
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D

Derailed

Registered
12 Nov 2019
21
Lansing, KS
Greg,
Thank you very much. I was going to order 1N5408s and hope for the best. I have ordered these.
I am thinking of using old pill bottles painted black or brown to make waterproof housings for the diode modules. Film cannisters are hard to come by these days or I would use those.
Dan
 
Greg Elmassian

Greg Elmassian

Registered
8 Mar 2014
4,175
San Diego
www.elmassian.com
I would solder wires to the array, and then dip the whole thing in that "liquid rubber" you can find at Lowes or Home Depot, basically encapsulating them. It's the soldered connections (dissimilar metals) that will be affected by moisture the most). Put it in a small trackside structure, you can get little plastic ones.

1584116758435.jpeg

Greg
 
D

Derailed

Registered
12 Nov 2019
21
Lansing, KS
The trains are stopping in the station like a charm. Nice and smooth and always stopping within a 2-3" spot. I love technology when it works. I didn't even have to change the wiring much. Just extended the blocks to the full station length and added the two diode arrays. Thank you for the help.