the MRH Forum

Signals Scenery and structures
Reply
New member 4 posts Gavine2009 New member 4 posts
Gavine2009

Can BLMA signals be wired to a twin coil switch machine to show switch indication??
Reply 0
Norman46 Regular poster 233 posts
Norman46

Twin coil switch machines

Twin coil machines need a momentary pulse to operate. The only way I have found to get an steady indication of the current position is to wire an Atlas Snap Relay in parallel with the switch machine. Perhaps someone else has a better solution. This shortcoming is one reason I won't be using twin coil machines on my current layout.
Norman Modeling L&N in HO circa 1953 We don't stop playing with trains because we grow old. We grow old because we stop playing with trains. Webmaster for http://www.locallocomodelrr.org
Reply 0
shoofly Regular poster 368 posts
shoofly

Simple is good...

I think your idea on installing an Atlas Snap Relay is a good one. Keeps it simple. There is a brand of Twin Coil switch machines that comes with SPDT contacts. They're made by Tenshodo. Not sure how available they are.

 

Chris Palomarez
Reply 0
Gavine2009 New member 4 posts
Gavine2009

Thanks, All my turnouts have

Thanks, All my turnouts have twin coil machines. I do have tomar dwarf signals wired to a few and they work great. I wanted to try something different was just unsure if BLMA would work. I like their style.
Reply 0
Gavine2009 New member 4 posts
Gavine2009

I do have Tenshodo machines.

I do have Tenshodo machines. Do BLMA have a colored wire for each LED like tomar dwarfs do??
Reply 0
LKandO Prolific poster 3,839 posts
LKandO

Latching Relay

You could also use a generic latching relay  http://www.digikey.com/product-detail/en/IM46GR/PB1091TR-ND/1633977 if the price is better.

Alan

All the details:  http://www.LKOrailroad.com        Just the highlights:  MRH blog

When I was a kid... no wait, I still do that. HO, 28x32, double deck, 1969, RailPro
nsparent.png 
Reply 0
dark2star Prolific poster 1,767 posts
dark2star

I remember a very nice circuit, but cannot find it anymore...

Hi,

there are lots of circuits how to get indication for twin-coil switch machines, e.g. ">http://www.1zu160.net/elektrik/images/weichenmeldung.gif">http://www.1zu160.net/elektrik/images/weichenmeldung.gif

These range from five to fifty parts per turnout...

The best one I remember used capacitors in series with the actual coils, thus providing a power spike for switching, protection for the coil (prevents steady current through the coil) and they had an option to add an LED, also. Still it was only a few parts (resistor, capacitor, diode). It really was the best circuit for twin coil switch machines I ever found.

Pity I cannot find it anymore.

If anyone has this circuit, please share...

Greetings.
Reply 0
burlington router New member 24 posts
burlington router

switch machine circuit

i have used this one. 

 

http://home.cogeco.ca/~rpaisley4/ToggleTwin.html
Reply 0
UPWilly Prolific poster 1,964 posts
UPWilly

Another source

Ken Stapleton, a Canadian, has a number of model train control circuits he has developed. He sells them either assembled or in kit form and variety of quantities. One of his designs, the model 751D and 751K may be the choice for your twin coil machines. You may want to see what he offers here:

http://www3.sympatico.ca/kstapleton3/751D.HTM

 

Bill D.

egendpic.jpg 

N Scale (1:160), not N Gauge. DC (analog), Stapleton PWM Throttle.

Proto-freelance Southwest U.S. 2nd half 20th Century.

Keep on trackin'
Reply 0
dark2star Prolific poster 1,767 posts
dark2star

Found a link last night

Hi,

as mentioned previously, there is a pretty nice circuit for twin-coil turnout machines. After a bit of a search last night, I found it:

http://home.cogeco.ca/~rpaisley4/ToggleTwin.html

Specifically the first circuit seems to be very appealing, few components and all the nice features:

- protection of coils / switch machines

- providing a current surge from a capacitor and thus

- protecting the power supply from that surge

- optional: indication

Have fun...

 
Reply 0
Reply