I want to provide route control in my yards with a 6 position rotary switch. With twin coil turnout motors, this seams fairly simple using a Cap Discharge, but with stall machines like Tortoise, how much power do I have to provide to turn each turnout (up to five), once the rotary is set and the SPDT switch is thrown?
Ric Z
The Tortoise each need about 18 ma current at around 12 vdc. I use a red/green LED in series with one Tortoise and they work just fine and the LED'/s have not burned out. I use about 9vdc so the Tortoise runs a little slower.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
http://mrr.trains.com/How%20To/Articles/Controls%20and%20Electrical/2011/06/Design%20procedure%20for%20yard%20ladder%20control%20using%20Tortoise%20switch%20motors.aspx
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
jrbernier http://mrr.trains.com/How%20To/Articles/Controls%20and%20Electrical/2011/06/Design%20procedure%20for%20yard%20ladder%20control%20using%20Tortoise%20switch%20motors.aspx Jim
Very nice link.
I downloaded all the photos in case this page ever goes away, plus stored the link in my browser.
This sure beats the day when I had to write a snail mail letter to the MRR magazine.
RicZ I want to provide route control in my yards with a 6 position rotary switch. With twin coil turnout motors, this seams fairly simple using a Cap Discharge, but with stall machines like Tortoise, how much power do I have to provide to turn each turnout (up to five), once the rotary is set and the SPDT switch is thrown? Ric Z
Stall-motor machines like a tortoise take constant power. What do you need the additional switch for? If you wire everying in the right direction (possibly using a bunch of diodes) the switches can just start throwing as you turn the knob on the rotary switch.
The capacitor discharge unit is definately not needed here, as it is simply designed to provide enough juice to instant throw multiple coil machines. Motor machines are constantly energized, you just need to change the polarity.
Chris van der Heide
My Algoma Central Railway Modeling Blog
Thanks, excellent article. If I can expand, one of my issues is POWER requirements. is there a limit to the number of machines, twin coil or stall, that can be operated off of a single 12 vdc power supply? If not what is the limit and power required for 5 or 6 machines, of one type of the other?
I have a number of under table twin coils that I can use which solve two problems for me 1) recycling available equipment and 2) under-table clearance on the second (top) level. Stall machines are preferable, but expensive and may need more clearance than I have.
BTW, there was a similar article on a yard ladder control in the December 1997, NMRA Bulletin, dealing with the truth table/matrix table approach.
RicZ
RicZ and 2) under-table clearance on the second (top) level. Stall machines are preferable, but expensive and may need more clearance than I have
and 2) under-table clearance on the second (top) level. Stall machines are preferable, but expensive and may need more clearance than I have
The LION sometimes mounts the machines along the rear fascia, or actually any place perpendicular to the switch that is convenient. On the upper surface of the layout, I use a motor tool to cut a trench from the throw bar to the machine. I use a piece of 1/16" welding rod with a 90° bend under the throw bar to reach the machine.
Set the machine by hand to a middle position, and slip a snip of wire insulation over the actuator. With fine copper wire, lash the welding rod the the snip of insulation. Center the turnout points, and then solder the lashing to the welding rod to lock it in place.
Done! an offset Tortoise!
LION runs more that 50 Tortoise machines on one transformer. Actually, I use two transformers, but if all of the turnouts are in the normal position, then they are all drawing power from only one of the transformers.
My transformers are 5 amp.
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
A Tortoise at 'full stall' draws only .018 amps! 100 of them would only draw 1.8 amps at 12 volts DC. Twin coil switch machine can draw lots of current when they throw. I have heard that a momentary surge of 5-6 amps for this old Kemtron/Tenshodo type machines is possible. If you are going to throw multiple switches at once(like cross-overs or ladders) a capacitive/discharge unit attached to the output of your power supply is a good idea. I had an old 2.5 amp power pack driving a C/D unit like this one:
http://www.walthers.com/exec/productinfo/475-PDC1
It is rated to throw up to 10 twin-coil motors at once, and not allow coil burnout.
Outstanding. Many thanks, I have all theinfo I need at this point. Now all I have to do is add it to my layout during the build - hopefully correctly.
Thanks again.
To know how many your power supply can drive, you need to know how powerful the power supply is. You say 12VDC, but knowing the amperage and/or total watts is key. (Maybe I missed you telling us that). For example if you've got a 12 watt power supply (doubtful), it will drive up to 1 amp of power needs(roughly). 18 Watts would be roughly 1.5 amps at 12 VDC.
Richard