Simond Posted January 20, 2015 Share Posted January 20, 2015 Thanks Ozzy, I think they were the people I got my first stepper motor for the turntable from. Good service from memory. Link to post Share on other sites More sharing options...
RMweb Gold Donw Posted January 20, 2015 RMweb Gold Share Posted January 20, 2015 Although the servos are cheap by the time to add in the control boards and sorting out something to do the frog switching is all mounts up. Tortoises are quite competitive on price to my mind. Don Link to post Share on other sites More sharing options...
Simond Posted January 20, 2015 Share Posted January 20, 2015 I don't disagree - there is undoubtedly a hassle-factor in using an Arduino-based solution, but it appeals to me. The bonus of having point & signal switching with full interlocking for about a fiver per lever is also attractive. If you fancy programming, it's the way to go. If you don't, then it will surely be more work than it merits, and Tortoises are reliable & versatile, but roughly three times the price. We can surely discount solenoid devices as crude, violent, noisy and unprototypically fast in operation! Best Simon Link to post Share on other sites More sharing options...
RMweb Premium 2ManySpams Posted January 20, 2015 RMweb Premium Share Posted January 20, 2015 I must admit that I'm planning on using the big green tortoises for Pencarrow's points. We have used them for about 20 years or so and, if you fit an external microswitch rather than relying on the feeble internal one, they are robust and seldom play up. Install and forget. We've tried the new DC Concepts version on BCB and I wasn't impressed. Took a lot of sorting out before they behaved and there have been failures. We've got servos on Treneglos operating the signals. They were generally ok but we had big problems with the servos picking up stray pulses in exhibition conditions and generally misbehaving. They have now forgotten their programming so have fallen out of use. Electronics isn't an interest or hobby for me. I just want electrical things to do as told and to carry on doing it without intervention. I may have another play with servos on Pencarrow's signals. Link to post Share on other sites More sharing options...
3 link Posted January 20, 2015 Author Share Posted January 20, 2015 (edited) Martyn when you get to the stage of connectiong the frame and the tortoises up I will send you a diagram. No point in doing it now things often change! BTW will you be at Bristol on Sunday? Don Hi Don, Thanks for the offer, and yes weather permitting I will be going to Bristol and also to deliver some track work I have built for Steve. Martyn, How will you operate the servos? You need a "something" between microswitch and servo, to control positions, speed, bounce, etc. MERG offer a suitable controller, Arduino is another option, and there is the Peco and at least one other commercial offering. If you have not yet bought your Tortoises, you'll probably find a servo solution for your points to be cheaper. I'd guess around £3 per servo, plus the cost of an Arduino clone, less than a fiver, plus micro switches, 50p, plus time and hassle. And if you go this route, it needs at least some programming - but full interlocking between signals & points is possible. It's possibly a project in its own right, however! Best Simon Hi Simon, I am planning on giving the MERG system a go, but at this stage I have not given it much thought. I have already brought 6 tortoise motors and installed them in the storage yard, and touch wood they all seem to be working OK. I brought 6 in one go which worked out about £11 each so not to bad. I just find them fool proof which is not a bad thing where I'm concerned . I have used some double pole switches just as a temporary measure at the moment just to control the points using a 9v transformer. ATB, Martyn. Edited February 5, 2015 by 3 link 1 Link to post Share on other sites More sharing options...
Simond Posted January 21, 2015 Share Posted January 21, 2015 (edited) OK, here we go, it is possible to arrange interlocking between a crossover with a slip to the bay per Martin's small track plan, and I am happy to say it works whether you use DPDT change over switches (diagram 1), or SPDT microswitches, and a split potential power supply (diagram 2). http://www.circuitron.com/index_files/INS/800-6000ins.pdf the trick is to wire the two motors for each crossover together (so they have a single switch, ie a single lever) and then to wire the bay motors through the auxiliary switch of one of the crossover motors. I've drawn the diagrams that look like this; DPDT switches - shown with the points set "normal" as per the diagram - this might mean swapping connections 1&8 on some or all of the motors Motor 10A, Motor 10B, Motor 15A, Motor 15B SPDT switches with Split Potential Power Supply - shown with the points set "normal" in both cases, if motor 10B is in the position shown, moving the lever for crossover 15 makes no difference, as the motors 15 are supplied directly from the power supply via the switches in motor 10B. if 10B is changed over, then the switches in the motor connect the lever 15 to the motors 15, and they can be switched, or not, as desired. In every case, the motors are powered, so they should be tight to the stock rails. Of course there is nothing to stop you pulling 15 off, before 10, which would be unprototypical, but if you do, it will all sort itself out. I should say that I have not tried this at home! (but I'm pretty confident) hope this makes sense! Simon Edited January 21, 2015 by Simond 1 Link to post Share on other sites More sharing options...
RMweb Gold Donw Posted January 21, 2015 RMweb Gold Share Posted January 21, 2015 I told you it could be done. Worth doing in m opinion for when you let friends have a go at the controls. I found that using two diodes to split 15vac into +ve and -ve half cycles worked well to provide a split supply with a common return. By adding a bipolar LED in series with the switch so it showed green in the switch was set normal and red if reversedgiving a useful panel display. Don Link to post Share on other sites More sharing options...
Simond Posted January 21, 2015 Share Posted January 21, 2015 I'm delighted to prove you right! (Actually, "prove" is a bit strong, as I haven't actually tried it, but as I said, I'm confident) Certainly worth avoiding the inevitable rending of expensive toys when the bay is set for "across" and the main is cleared for the express... The "AC & diodes" version is essentially the same as the split potential diagram. I have never tried the diode indicator option, as I prefer the switches/levers to represent the settings, but it certainly has it's uses. Of course, going back to the discussion about interlocking, if the driver doesn't follow the signals, there's little point in having them, making them work, or interlocking them with the point work, but at least locking the points so conflicting moves are minimised seems very worthwhile. Best Simon Link to post Share on other sites More sharing options...
3 link Posted January 21, 2015 Author Share Posted January 21, 2015 (edited) Hi Simon, Don, Thank you so much Simon, you have made the wiring diagram much clearer to understand. I think at this stage I will go for the DPDT option, as it makes more sense to me than the Split Potential Power Supply. I have almost completed the baseboard that the said crossover will be on, so I will soon be able to put it all to good use. Thank you again for the time spent on putting that diagram together for me. ATB, Martyn. Edited January 21, 2015 by 3 link Link to post Share on other sites More sharing options...
Simond Posted January 22, 2015 Share Posted January 22, 2015 Martyn I'm very pleased it will be helpful. Please don't hesitate to shout if something appears not to work as you expect. The split potential version suits your desire to use a lever frame with micro switches, and there is rather less wiring to do at the switches. It is no more complex, it's just that you need two power supplies - these must be proper isolating transformers, not auto-transformers, and whilst I haven't tried it, I suspect the switch-mode supplies for phones etc., will not work either. (Shame, cheap option!) Having got two suitable supplies, you connect the + of one to the - of the other. This is your mid-potential point, and is connected to all the motors as the "6V" in my diagrams above. The + of one supply is labelled "12V" above and should be connected to the switches' "NO" contacts, and the - of the other is labelled "0V" and should be connected to all the switches' "NC" contacts. You may need to swap the 1&8 connections at the motors to get the points all in the right position. As you are probably aware, the Tortoise motors will operate on less than 12V, - the split potential can be 0, 6, 12, or 0, 9, 18, or even 0, 12, 24. It doesn't matter, though I suspect if you connect it wrongly, 24V would make the motor a little warm. (They should only see half of the maximum if connected correctly). Gaugemaster offer a suitable power supply here http://www.gaugemaster.com/item_details.asp?code=GMC-M1DC&style=&strType=&Mcode=Gaugemaster+M1DC but cheaper options are available. If you want to try it out, without buying a power supply, a pair of PP3 batteries will work for a while. Do disconnect when not using, or they'll go flat over a day or two. Best Simon Link to post Share on other sites More sharing options...
RMweb Gold Donw Posted January 22, 2015 RMweb Gold Share Posted January 22, 2015 It is so much simpler to use two diodes. You need a spare output from a transformer many have a 15v ac for accesories. I find it difficult to draw using the laptop will do a diagram. Don Link to post Share on other sites More sharing options...
Simond Posted January 22, 2015 Share Posted January 22, 2015 Don't worry Don, there's a diagram in the Tortoise "manual" in the link in my post above, I can easily make another sketch if it would be helpful. I'll find a suitable diode in Maplin's catalog! BR Simon Link to post Share on other sites More sharing options...
3 link Posted January 22, 2015 Author Share Posted January 22, 2015 Hi Simon, The way you have explained the split potential version does seem just as viable, and what with less wiring even more interesting. I am using a 9v transformer at present, but I do have an old controller with 15v accessories outlet, does this need to be ac or dc? ATB, Martyn. Link to post Share on other sites More sharing options...
RMweb Gold Donw Posted January 22, 2015 RMweb Gold Share Posted January 22, 2015 I think I used two 1N4001. 10 for a pound on ebay now (probably +P&P) Don Link to post Share on other sites More sharing options...
ozzyo Posted January 23, 2015 Share Posted January 23, 2015 I think I used two 1N4001. 10 for a pound on ebay now (probably +P&P) Don Hello Don, what are 1N4001s please. I'm thinking batters? Link to post Share on other sites More sharing options...
Simond Posted January 23, 2015 Share Posted January 23, 2015 Ozzy, diodes! http://www.maplin.co.uk/p/1n4001s-1a-silicon-rectifier-ql73q this is fiendishly expensive, but of course, quick and convenient datasheet here;- http://www.diodes.com/datasheets/ds28002.pdf RS are way cheaper, but then again, you need two, not 100... http://uk.rs-online.com/web/c/?sra=oss&r=t&searchTerm=1n4001 as Don suggested, eBay seems to be the preferred source http://www.ebay.com/itm/50-x-1N4001-Diode-1A-50V-Free-Shipping-/260820238278 HTH Simon Link to post Share on other sites More sharing options...
RMweb Gold Donw Posted January 23, 2015 RMweb Gold Share Posted January 23, 2015 Martyn the supply needs to be AC when it goes positive the suppy through one diade becomes live when it goes negative the supply through the other goes live. The motors see a serioes of pulses. It did not affect them in any way stood up to plenty of two day exhibitions and with only five turnouts on a shunting plank they were being changed over all the time. I will see if I can find a couple of diaodes and bring them to bristol. Don Link to post Share on other sites More sharing options...
3 link Posted January 23, 2015 Author Share Posted January 23, 2015 Hi Don, Thank you for the offer of the diodes, I will be with Steve for some of the day on Sunday and he usually dresses in a brighter outfit than myself so we should be quite easy to spot. Still at least it looks like the weather will be fine which is a good thing as I have a fair distance to travel, still it's worth it as it's a great show. ATB, Martyn. Link to post Share on other sites More sharing options...
3 link Posted January 24, 2015 Author Share Posted January 24, 2015 Hi Guys, Well the second scenic board is just about ready to start laying some track on, this second board will be for the two platforms and station area and possibly a gradient leading to a private siding. I have laid out the Templot plan roughly in place, just to get an idea of what could fit where, and also to make sure there are no cross members where the point motors will be placed. Sorry for the grainy photo, taken from my iphone in haste. ATB, Martyn. 5 Link to post Share on other sites More sharing options...
RMweb Gold Donw Posted January 25, 2015 RMweb Gold Share Posted January 25, 2015 Sorry to miss you at Bristol. I did meet a lot of friends. Diodes were on sale on Squires stand at 8 for 45p. Having discovered I had used up my supply I bought some. Let me know if you want a couple. Don Link to post Share on other sites More sharing options...
3 link Posted January 26, 2015 Author Share Posted January 26, 2015 Hello Don, Yes it was very busy, it took me over 2 hours just to locate Steve and he always wears some bright attire. Never mind there's always Telford mind you that gets busy as well especially on the Saturday. Regarding the diodes, I did not know Squires stocked them and being that their shop is a 5 minutes drive from my home, Bingo ! Do you know what one's I must ask for ? ATB, Martyn. Link to post Share on other sites More sharing options...
RMweb Gold Donw Posted January 26, 2015 RMweb Gold Share Posted January 26, 2015 The diodes are 1N401 which can carry one amp. The packet has a yellow sticker with 700005 on it presumably a Squires number. The diodes have a silver band at one end Don Link to post Share on other sites More sharing options...
RMweb Gold Donw Posted January 27, 2015 RMweb Gold Share Posted January 27, 2015 Don. Do you mean 1N401? That is a zener diode. Martyn needs a 1A signal diode, ie a 1N4001. The silver band is at the -ve end, the cathode. I plead old age. They are indeed 1n4001 as I first quoted. The diodes are connected the opposite way round to each other. When wiring up Tortoises you may need to swap the connections to pins 1 and 8 depending which way round you want the 'normal' setting to be. Don Link to post Share on other sites More sharing options...
3 link Posted January 27, 2015 Author Share Posted January 27, 2015 Thank you Don, Paul, I will get there in the end . Martyn. Link to post Share on other sites More sharing options...
Simond Posted January 27, 2015 Share Posted January 27, 2015 Martyn Look at the diagram in the tortoise data sheet, you'll see two diodes connected to one side of the transformer. One is pointing to it, and one pointing away. It doesn't actually matter which is which in this arrangement as long as they are not both pointing the same! Connect one side (eg NC) of all your point switches to one diode, and the other side (eg NO) of them all to the other diode and keep your fingers crossed! If you really want to exactly follow the diagram, this is what the band means I will get round to finishing your wiring diagram - been a big busy, and travelling last week, so apologies for the delay Best Simon Link to post Share on other sites More sharing options...
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