Jump to content
 

Extra switch for cobalt


zedcell
 Share

Recommended Posts

25 minutes ago, Nigelcliffe said:

BM1 needs an "on" contact when the controlled section is "proceed at normal speed", and an "open" connection when the controlled section is "brake to a stop".   

I did a bit of research on Lenz's site & if i understand correctly the the following drawing  could work

Assuming you are running in the direction of the arrow then the BM1 will protect the point

 

I believe you can protect the main line ,siding or both with 1 or 2 BM1's

 

The physical orientation of the cobalt will determine weather  you need to use Cobalt term's 5 & 6 for the main ,5 & 7 for the siding

or 5 & 7 for the main, 5 & 6 for the siding.

If the switches in the cobalt are oriented as in the drawing & the turnout is straight then a train coming from the siding should stop in the braking section & a train coming from the main should proceed 

If the opposite happens then wires from the BM1's to the cobalt term's 6 & 7 should be swapped

Cobalt terminal 5 goes to both BM1's & can also be connected to the DCC bus (red feed)

 

880579053_CobaltandsignalrelayV6.png.18a626ed4c399fd8f1e0dcd44766ad66.png

 

 

John

 

  • Friendly/supportive 1
Link to post
Share on other sites

John that looks like a great idea didn't realise you could use 2 BM1 modules connected to 1 cobalt this could save me a lot of time and confusion, i am assuming the power would be 9V DC from terminal 5 from the cobalt.

Thanks again for your invaluable advise on this issue.

Link to post
Share on other sites

As i understand the BM1 it has 2 terminals 

One goes to the track feed

The other goes to the insulated section breaking section

1 hour ago, zedcell said:

i am assuming the power would be 9V DC from terminal 5 from the cobalt.

NO, The BM1 doesn't require a DC supply 

As i said earlier 

11 hours ago, John ks said:

Cobalt terminal 5 goes to both BM1's & can also be connected to the DCC bus (red feed)

This is based on drawings found on google

The numbers on the bypass switch correspond to the Cobalt terminals

the red wire from the BM1 & bypass switch goes to the rail . Instead of being connected to the rail it could be connected directly to the DCC Bus

646238231_Bm1connection.png.94db58f474d7a63fa665575063f6502a.png

 

 

John

 

PS follow this link. EDIT you may have to copy & paste it into google search 

Automatic Brake Control - DCCWiki

 

 

Edited by John ks
  • Thanks 1
Link to post
Share on other sites

Hi John /Nigel

i can now confirm following your advice and guidance i have successfully set up signal operation via the cobalt with the aid of your last diagram:good_mini:

Unfortunately im not having much success with the abc braking, having  competed the wiring as in above diagram soldering the feds 1 and 2 to the track via the bm1 module and connecting back to the cobalt via terminals 5 and 6  have also cut the track for the isolation sections.

Selected a Bachmann class 20 loco with a ESU v4 chip for the test and turned on cv 27 = 1  slow approach cv 123 = 100 (default)  abc sensitivity cv 134 = 12 (default)

Started test, set signal for spad protection and to my dismay the loco did not respond, back to the program track to check cv changed bm1 module changed loco no luck.

Have only connected the approach for one side of the point for testing.

The only difference i can find is in your diagram you show the feds to the track bus as red  in the direction of travel where as mine are black in the direction of travel and it states in the lenz instructions always connect to the right hand track in the direction of travel, there is no mention of polarity.

Would be good if you could  help kick me over the line with this issue.

 

                                               Regards Richie

Edited by zedcell
Link to post
Share on other sites

Suggest you sort out the BM1 on a bit of test track on the bench before going to the layout. 

 

Which Rail to cut ?  BM1 instructions say use the "right" rail, but the diagrams above show the left rail approaching the turnout from the frog side.  This isn't a huge issue, provided the activation bit in the decoder (CV27) is set correctly.   It does matter that you do it consistently around the layout, and that the braking sections are long enough.  

CV27=1 for right rail,

CV27=2 for left rail,

CV27=3 for both rails (but with consequence cannot reverse away from stop section).  

 

And, if you have wheels which could pickup power in a train (eg. carriage with pickups intended for lighting) this can mess things up badly.   As the carriage crosses the rail gap, it acts as the by-pass switch, setting things to "no brakes".  There are solutions for this, but requires much longer brake zones and additional hardware.   

 

Braking starts when the last wheel of the loco (which is fitted with pickups) is in the braking zone.  Whilst the loco has a wheel on the "normal" track, it's pickups act as a by-pass switch for braking. 

 

 

 

The slow approach speed CV127 is irrelevant, this is not a BM2 slow-approach (generates a different signal for slow-approach).  

 

The BM1 MUST be connected the right way round.  Though there are only two track terminals they are different.  Connect it back to front is the equivalent of putting it on the other rail.   Terminal-1 to the track bus, terminal-2 to the braking section.     If you have this back-to-front, then the loco will stop in the "wrong" (driving away from the turnout), but will drive through in the normal direction.  

 

 

So, for testing on the bench, take a length of track, with an isolation break in one rail, and connect up the BM1 (getting the terminals correct).   Set CV27 for the appropriate rail gap side.   Drive train on this test length, and it should decelerate to a stop on entering the brake section (if your locos have very high deceleration values in CV4, you may have to hold the loco whilst it decelerates). 
Next, work out the by-pass switch for normal running.   If the brake section is set to "normal" running, the switch connects terminal-1 and terminal-2 on the BM1.    Connect such a switch and test it - switch closed and there is no braking (bypass braking), switch open and braking works.   

Finally, if locos don't stop quickly enough (because of high deceleration value in CV4), decide if "constant braking distance" will help (CV253, 254, 255)  

 

Having got a bench test to work, you can transfer it to the layout and wire one brake zone, systematically, there.  First connect the BM1 and prove that loco will stop as it approaches.   Next connect the by-pass switch to the turnout motor and prove that the bypass works correctly when turnout (and signal) set to proceed, and prove that the loco still stops when turnout and signal set to stop.   

 

 

 

The polarity of the DCC signal into the layout (from command station, via wiring, to rails) doesn't matter.   It does matter within the loco (ie. that the right hand rail pickup goes to the "right hand rail decoder" connection), but if these are commercial locos with decoders fitted to sockets, those will be correct.  

 

 

 

- Nigel

Edited by Nigelcliffe
Link to post
Share on other sites

47 minutes ago, zedcell said:

The only difference i can find is in your diagram you show the feds to the track bus as red  in the direction of travel where as mine are black in the direction of travel and it states in the lenz instructions always connect to the right hand track in the direction of travel, there is no mention of polarity.

 

As i said earlier my only knowledge of the BM1 is from research on the internet

I've changed the drawing to move the gaps to the RH rail in direction of travel & the feed colours (i originally picked the feed colours at random)

798024295_CobaltandsignalrelayV7.png.102e28006116982c2a3f11ebf6cb7614.png

Which terminal of the BM1 that is connected to the breaking section may be critical to the operation of the BM1

Nigel posted while i was writing this post 

Anything i was going to say have been done by Nigel who is a lot more knowledgeable then me regarding the BM1

John 

 

 

 

 

  • Thanks 1
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...