Melting Switch Machines


N

ntrainman

Clueless
I am building an old Atlas n scale layout Railroad N-109 in the Nine Scale model railroads 2nd edition. I'm using the old technology, 4 transformers and 21 remote switches, all Atlas parts. Switch machines keep melting. I am electronically challenged. I have been reading about capacitor discharge units but can't seem where to buy them in the U.S. Does Atlas have a problem with the turnout throws sticking? I have checked and double checked the wiring to the rails and switches with the blocks and everything is as the diagram shows it. I have had to replace two switch machines and just discovered a third totally melted? What should I do? Please HELP!
 
What type of electrical "switches" are you using to actuate the turnout machine? It has to be "momentary", that is just a quick hit and release. If you hold it down or the electrical switch hangs up and stays on the turnout motor will indeed melt.

Armchair
 
The actuators that came with the Atlas N 80 switches. They are the standard left, right and push down momentarily to actuate. However, they are getting current from somewhere. I was checking last night going through all the actuators to make sure they were working the switches and checking the current. I noticed one wasn't moving and saw that the entire plastic cover over the machine was gone, melted.
 
Last edited by a moderator:
Im HO and Ive melted 2 myself of Atlas' in the last year. All I can tell you is:
the switch machine box (not the $9 mechanism) itself are cheap, and they get stuck very easily. It doesnt take long for one to make a great deal of heat on the remote switch and viola you got a melted mess.
 
Thanks. But for the electronically handicapped/challenged. Is that easy to build or can you buy them. And, for 20 switches do I need just one or several coming out of the transformer and to several sets of acutator banks?
 
just a thought- are you using the AC side of the transformer for the power source?
 
No. I have double checked polarity as well. The switches are hooked up to the A.C. side and the mainline rails are hooked up to the D.C. side. I'll see if I can figure out how to attach the layout and wiring diagrams.
 
Last edited by a moderator:
Here is the message that I received via email- note that it is the reverse of what your post says- Because if your switches are in fact hooked up to the DC, that would cause problems.
***************
No. I have double checked polarity as well. The switches are hooked up to the D.C. side and the mainline rails are hooked up to the A.C. side. I'll see if I can figure out how to attach the layout and wiring diagrams.
***************

According to the instructions that come with Atlas switches, the power source should be AC. DC is for the track.

Norm
 
You can use either AC or DC (12-14v. fixed voltage in either case)for the switch machines, and the variable DC for the track. I think your problem lies with the A's controllers. The ONLY A's product I use is their flextrack and avoid everything else....
 
Train Layout & Wiring

Here are the train layout and wiring diagram that I used. The switches are hooked up to the A.C. side of CAB A.
 
Train layout and wiring diagrams

I thought these got uploaded yesterday.
What manufacturer of track and switches do you recommend?
Everything I have is Atlas. I also used individual track segments, not flextrack.
Was that a mistake?
 
In my humble opinion, no it is not a mistake. From what I have learned so far there are no mistakes. The only thing I do not like about the preformed track is the "sudden turn" of a curve track. With the flex track you can form an easement into it and the trains look more realistic entering the curve instead of "snapping" I too, am building an N scale layout with nothing but Code 80 track and atlas switches. So far all of my rolling stock has micro trains trucks and couplers and performance is fantastic. I still have a few bumps I am working out but I like the way it all works. I am currently using the custom line of switches and had originally intended to use undertable machines, but I am thinking that may be too much work for me. So, I am probably going to go to the remote switches instead and just disguise the machines as I don't like the way they look on a layout. I love your layout for the size table you have and wish I had been a little more compact when desinging mine.
 
I am playing with the cabs to understand better what power what. It's interesting that I can run the lower pike on only CAB B and throw the switches manually. CAB A only seems to run the switch machines. Which is exactly what the wiring diagram shows for the AC side. Without CAB A on CAB B can run power to the rails. I was playing with CAB C and D and the upper pike last night. I think I have some backward wiring because the loco seemed to have automatically changed direction when it went from one power zone to another. The lower block power switches are off when up and on when down. The upper block power switches are just the opposite. Also haven't gotten the CML, DML, R & S as well as the two INT switches to work or figured out. If I have backwards wiring on those blocks that may be why.
 
When using Atlas (or any twin coil switch machine), it's a good idea to use a Capacitive Discharge power supply. That makes sure that ony a momentary "blast" of power is sent to the switch machine. Once the buttone is pushed, the supply must recharge before sending more power. This prevents continuous power form flowing and burning out the switch machines.

The Circuitron 5303 Snapper Switch Machine Power Supply is one possibility. Supplies can be easily built, a little searching the net should up parts lists and schematics.

I built one years ago, handful of parts from Rat Shack. Still works fine.
 
One Capacitive Discharge power supply, YES. Hook it up to the switches you use to throw the turnouts.

The key to a CD supply is the one time, short duration, blast of energy that throws the turnout. After it does a cycle, it must "recharge". If the button to the turnout is stuck, it cannot recharge, preventing the switch machine from burning out.
 
Steve58 said:
If the button to the turnout is stuck, it cannot recharge, preventing the switch machine from burning out.
Click to expand...

thats only if your CDU has charge blocking circuit built in. otherwise while capacitor is depleted, the supply line itself energizes the coil via stuck button. hint - semiconductors (transistors and opto-couplers) are dirt cheap and never stick :)
 
You must log in or register to reply here.



Back
Top