sb67 Posted March 1, 2017 Share Posted March 1, 2017 Can anyone tell me if this type of microswitch can be used to change point polarity? It would be operated by the end of a push rod which switches the point. Seen loads for sale on e bay, some are really cheap! Thanks. Steve. Link to post Share on other sites More sharing options...
Judge Dread Posted March 1, 2017 Share Posted March 1, 2017 Can anyone tell me if this type of microswitch can be used to change point polarity? It would be operated by the end of a push rod which switches the point. Seen loads for sale on e bay, some are really cheap! Thanks. Steve. TAM-046-000.jpg I don't see why not. Link to post Share on other sites More sharing options...
DCB Posted March 1, 2017 Share Posted March 1, 2017 Yes. You can also drive them direct off the point motor or off the end of the tie bar. if you don't have motors or remote operation. I have been using them for over 20 years on DC without a single failure Link to post Share on other sites More sharing options...
Crosland Posted March 2, 2017 Share Posted March 2, 2017 There may be a reason why some of them are cheap. Don't be tempted to fix them with superglue. Don't ask how I know. Link to post Share on other sites More sharing options...
RMweb Gold Stubby47 Posted March 2, 2017 RMweb Gold Share Posted March 2, 2017 Notwithstanding DavidCB's comment, I tried using some for indicating if a hidden siding was occupied (push the train back against the switch at the end of the line). The spring was far too strong for the weight of the train. My point (sorry...) is the spring might be too strong for the push rod and not allow the point to be switched, or stay switched. Link to post Share on other sites More sharing options...
cliff park Posted March 2, 2017 Share Posted March 2, 2017 You can usually solder to the operating arm, eg a long piece of stiff copper wire or brass strip, and then they operate at the lightest touch. The other thing is to watch the connections, not what you would expect. Some have a picture on the side, the changeover contact will be one end, not the middle. Link to post Share on other sites More sharing options...
Suzie Posted March 2, 2017 Share Posted March 2, 2017 They are fine. They are a standard size product so you can find the same thing in a variety of qualities, but most will be good enough for what you want. You will have to be careful when positioning so that the activation point is just on the balance to prevent too much force being applied one way, you might like to use a pair operating from both ways to balance to force. Use the smallest type you can find. The V4 style microswitches are quite cheap anyway so if you need a few don't bother with eBay - go straight to an electronics distributor and get a reasonable quality product that will last. Some at Rapid here:- https://www.rapidonline.com/rvfm-subminiature-v4-microswitches-73543 Link to post Share on other sites More sharing options...
RMweb Premium dhjgreen Posted March 2, 2017 RMweb Premium Share Posted March 2, 2017 Notwithstanding DavidCB's comment, I tried using some for indicating if a hidden siding was occupied (push the train back against the switch at the end of the line). The spring was far too strong for the weight of the train. My point (sorry...) is the spring might be too strong for the push rod and not allow the point to be switched, or stay switched. Did you solve this? You may just be able to see me doing this in my avatar, they are expo tool parts. I can dig out the right part no if you need it.Edit, sorry for the highjack, but the info may help the OP too. Link to post Share on other sites More sharing options...
sb67 Posted March 2, 2017 Author Share Posted March 2, 2017 Thanks for the info guys. I've ordered some so I'll look forward to trying to get them to work! I'm guessing there wont be instructions so how would I know which wires to go where? Steve. Link to post Share on other sites More sharing options...
Suzie Posted March 2, 2017 Share Posted March 2, 2017 There should be markings by the terminals. C=Common (to frog) NO=Normally Open (to the stock rail closest to the switch) NC=Normally Closed (to the stock rail furthest from the switch). Link to post Share on other sites More sharing options...
gismorail Posted March 2, 2017 Share Posted March 2, 2017 If you have a look at my layout topic Chumley End you can see how I have fitted them to servo motors , you can do the same with any point motor by just using the action of the point to depress the micro switch, simple and fail safe Link to post Share on other sites More sharing options...
sb67 Posted March 2, 2017 Author Share Posted March 2, 2017 There should be markings by the terminals. C=Common (to frog) NO=Normally Open (to the stock rail closest to the switch) NC=Normally Closed (to the stock rail furthest from the switch). Thanks for that, I've seen those markings and always wondered what they meant. Link to post Share on other sites More sharing options...
RMweb Premium BR60103 Posted March 3, 2017 RMweb Premium Share Posted March 3, 2017 preparing microswitch to go into the slot in the baseboard. The slot should be fairly tight to hold the switch, but long enough to adjust against the throw bar. 2 microswitches installed. Not shown: a square of scribed wood is glued to the top of the switch and spiked or pinned down. This holds the microswitch sideways but can be unpinned to adjust the movement. I made a device with a pair of bulbs and 3 clips to test polarity of the frog during installation. Link to post Share on other sites More sharing options...
terrysoham Posted March 3, 2017 Share Posted March 3, 2017 This is how I used mine on the Peco points in the storage area on Neely. I used Tortoise n the scenic side so don't need them there. Link to post Share on other sites More sharing options...
Suzie Posted March 3, 2017 Share Posted March 3, 2017 This is how I used mine on the Peco points in the storage area on Neely. I used Tortoise n the scenic side so don't need them there. This picture shows nicely which terminal is which:- C (blue wire to frog) is the end terminal furthest spaced. NO (black wire to nearest stock rail) is the middle terminal. NC (red wire to farthest stock rail) is the other end terminal. Link to post Share on other sites More sharing options...
DCB Posted March 4, 2017 Share Posted March 4, 2017 Notwithstanding DavidCB's comment, I tried using some for indicating if a hidden siding was occupied (push the train back against the switch at the end of the line). The spring was far too strong for the weight of the train. My point (sorry...) is the spring might be too strong for the push rod and not allow the point to be switched, or stay switched. Some Microswitches are indeed too strongly sprung but these are a generally heavy duty 4 or 10 amp. Also if you drive the plunger directly rather than use the extension lever it can give an awkward and stiff action. I always try to use the very tip of the extension arm if I can. generally there is very little spring when the switch has gone over centre and I find Peco point springs are more than up to holding my microswitches closed and the point blades hard against the stock rails. Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted March 4, 2017 RMweb Premium Share Posted March 4, 2017 Thanks for that, I've seen those markings and always wondered what they meant. Whatever you do, NEVER assume the configuration of contacts, is a particular way without checking it first! A late friend of mine did that, with a whole bunch of 4 pole relays that he replaced on his layout. That created an absolute mess, for which the layout never fully recovered. It was on a fully interlocked layout and he managed to short out both main lines together, and to the Common Return. He was devastated & admitted that he ought to have known better! Moral of story, if not sure, please test or ASK before going blindly ahead. Link to post Share on other sites More sharing options...
sb67 Posted March 4, 2017 Author Share Posted March 4, 2017 Thanks Kevin, I'll remember that. Just got to wait for my switches and then I'll post how I get on. Steve. Link to post Share on other sites More sharing options...
RMweb Gold Stubby47 Posted March 5, 2017 RMweb Gold Share Posted March 5, 2017 Did you solve this? You may just be able to see me doing this in my avatar, they are expo tool parts. I can dig out the right part no if you need it. Edit, sorry for the highjack, but the info may help the OP too. No, but then things changed and I built a traverser instead. I also considered infrared detectors, but discarded those too. Link to post Share on other sites More sharing options...
RMweb Premium dhjgreen Posted March 5, 2017 RMweb Premium Share Posted March 5, 2017 No, but then things changed and I built a traverser instead. I also considered infrared detectors, but discarded those too. If ever you need it, the Expo part number is A280-31. Link to post Share on other sites More sharing options...
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