RMweb Premium ColinK Posted December 29, 2023 RMweb Premium Share Posted December 29, 2023 Hi, one of my friends has asked me to help him with the wiring on his layout. While track power is DCC, points control is by Peco solenids powered by 16v AC using a probe and stud. I know how to modify and wire up the normal 2 way electrofrog points. When I come to the symetrical three way points, I think I know how to wire the actual frogs, but do I need to modify the points by cutting links between the rails and adding jumpers? To avoid damaging the points in use, ideally the two point motors would be switched in the correct order so that the one furthest from the toe end can only change when the first set of blades are facing the correct direction. There is a very useful explaination on the DCC Concepts website on how to achieve that on a asymetrical three way point using DCC control, but is there a way of doing this when the points are controlled by 16v AC using a probe and stud? Thanks PS the layout is dual 16.5 and 12mm gauge including a short section of dual gauge track, but we’ll come to that in a few months time. Link to post Share on other sites More sharing options...
2E Sub Shed Posted December 29, 2023 Share Posted December 29, 2023 (edited) 5 hours ago, ColinK said: Hi, one of my friends has asked me to help him with the wiring on his layout. While track power is DCC, points control is by Peco solenids powered by 16v AC using a probe and stud. To avoid damaging the points in use, ideally the two point motors would be switched in the correct order so that the one furthest from the toe end can only change when the first set of blades are facing the correct direction. Had a similar situation and used switches connected to the point solenoids so if one set of blades was not set to middle track, then the feed to the other solenoid was broken, so it could not be thrown until the other set of blades was set to the middle track. Assume you will wire both sides of the point solenoid to the central road stud, so remembering to "normalise" the point blades before every selection may be an easy option without above. In my case was a simple situation as point is visible from control position and is only point on layout. Otherwise (which I assume the DCC instructions quoted provide) a means of sequencing the throw of the point blades, so that when you set for the left track, the right track is set to the middle road first, then a short delay and the blades move to the left track. and vice versa. for the two diverging route studs, and wire central as above. Edited December 29, 2023 by 2E Sub Shed Add missed text 1 Link to post Share on other sites More sharing options...
Titan Posted December 29, 2023 Share Posted December 29, 2023 Easiest way is a diode matrix. One stud for each direction and the appropriate solenoids for each direction fire simultaneously. No need for normalisation or any switching, but a CDU will almost certainly be required if you have not already got one. 1 1 Link to post Share on other sites More sharing options...
RMweb Premium ColinK Posted December 29, 2023 Author RMweb Premium Share Posted December 29, 2023 Many thanks for your replies. The first suggestion seemed to be easy, just add an accessory switch onto one point motor, so the second one could not be changed if the first set of blades were in the wrong position. But quite by chance I discovered detailed instructions for the diode method on Brian-Lambert’s website. I’m tempted to try the diode method first as it doesn’t need any physical switches. Only concern is that it uses 1N5401 diodes which have a maximum current of 3 amps. Wonder if diodes with a 5 amp rating would be better? No idea what those diodes would be though. Link to post Share on other sites More sharing options...
Titan Posted December 29, 2023 Share Posted December 29, 2023 I think I used 5 amp diodes on mine - they only have to sustain momentary current rather than continuous, but even so and with diodes being cheap I would much rather fit and forget as it were. 1 Link to post Share on other sites More sharing options...
Brian Posted December 30, 2023 Share Posted December 30, 2023 Hi While I have not had any issues using 1N5401 diodes, there is no reason why a 5Amp (or greater amperage) diode can't be used along with a suitable CDU. 😀 1 Link to post Share on other sites More sharing options...
RMweb Premium ColinK Posted December 30, 2023 Author RMweb Premium Share Posted December 30, 2023 2 hours ago, Brian said: Hi While I have not had any issues using 1N5401 diodes, there is no reason why a 5Amp (or greater amperage) diode can't be used along with a suitable CDU. 😀 Thanks Brian, is there a particular diode number I should use that has a 5 amp rating eg 1Nxxx? Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted December 30, 2023 RMweb Premium Share Posted December 30, 2023 9 minutes ago, ColinK said: Thanks Brian, is there a particular diode number I should use that has a 5 amp rating eg 1Nxxx? Here's a chart with the ratings. https://www.vishay.com/docs/88503/1n4001.pdf The table marked 'Maximum Ratings' is what you want. The parameter row shows the different types and the amount of reverse blocking and next 3 rows the values. Also the row that tells you the maximum forward current (row 5). Beyond that gets technical and rather OTT for your requirements. As you can see they quickly get quite high and are really overkill for your needs. HOWEVER the price for going up levels is generally very marginal, so on that, buy on price and convenience. 1 Link to post Share on other sites More sharing options...
Brian Posted December 31, 2023 Share Posted December 31, 2023 Hi This is just an example.... eBay 6Amp diodes x 5 Link to post Share on other sites More sharing options...
RMweb Premium ColinK Posted December 31, 2023 Author RMweb Premium Share Posted December 31, 2023 Many thanks Brian. Given that the diode board will be very difficult to access once the layout is finished, I would rather go with the higher rated diodes to be on the safe side. Link to post Share on other sites More sharing options...
RMweb Premium ColinK Posted January 7 Author RMweb Premium Share Posted January 7 One three way point all wired up. I don’t have a CDU yet, but when I apply 16v AC (1.25A transformer) to the wires that go to the CDU and studs, nothing happens. Have I got the diodes the wrong way round? Link to post Share on other sites More sharing options...
Free At Last Posted January 7 Share Posted January 7 18 minutes ago, ColinK said: One three way point all wired up. I don’t have a CDU yet, but when I apply 16v AC (1.25A transformer) to the wires that go to the CDU and studs, nothing happens. Have I got the diodes the wrong way round? Have you tried using a dc supply? Link to post Share on other sites More sharing options...
RMweb Premium ColinK Posted January 7 Author RMweb Premium Share Posted January 7 Thanks, I’ll have to try and borrow one, or a CDU. Perhaps my transformer just hasn’t got enough grunt to move two solenoids at once. Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted January 7 RMweb Premium Share Posted January 7 4 hours ago, ColinK said: Thanks, I’ll have to try and borrow one, or a CDU. Perhaps my transformer just hasn’t got enough grunt to move two solenoids at once. Does it throw one at a time? Try one wire of your AC held in temporarily in the terminal block with the green wires, then any one of the two red or black terminals with the other. Don't worry about screwing the wires in, or that the diodes are connected. Link to post Share on other sites More sharing options...
Brian Posted January 8 Share Posted January 8 The circuit is not designed to work on AC. A CDU, even when feed with AC, produces a DC output. If no CDU is used you need a DC power source of around 19 to 21 volts DC at 3.5 Amp or greater current. Ideally a CDU is best and then the current rating of its power supply doesn't need to be that great and a 1.0Amp 16v AC power source will be fine. Ideally opt for a CDU with at least two capacitors each 2200uF or a single capacitor value of at least 4700uF. You can if wished go for a higher value of capacitor too. 😄 1 Link to post Share on other sites More sharing options...
RMweb Premium ColinK Posted January 8 Author RMweb Premium Share Posted January 8 Doh - I’ve been so stupid (maybe I can be excused a bit as I’m recovering from shingles on my face). Of course with diodes it has to be DC - why hadn’t I realised that. Second, if you look at the photo close enough you can see my mistake, the diodes link the input and output sides on the circuit board, but I had missed off the link between the green wires which are the common return to the solenoids - so there was a gap in the circuit. Third, none of the power supplies I have are sufficienly powerful, so testing will have to wait until I take them over to my friend whoose layout they are for (I’ve got the job of wiring it, and it includes some dual gauge track). But the good news is, that the solenoids do buzz when current is getting to them, so hopefully everything is fine. Hope so as I’ve just made up another diode matrix for the other three way point. Thanks everyone for your help. 1 1 Link to post Share on other sites More sharing options...
DCB Posted January 12 Share Posted January 12 (edited) On 07/01/2024 at 15:39, ColinK said: One three way point all wired up. I don’t have a CDU yet, but when I apply 16v AC (1.25A transformer) to the wires that go to the CDU and studs, nothing happens. Have I got the diodes the wrong way round? I string the diodes between two of those white connector blocks (insulate the bare wires) screwed to a bit of hardboard. My 1N400 diodes have worked for the past 30 years. Including operating 3 way points. I use a 6 way rotary switch with a 5 amp rated push button to energise to operate my fiddle yard where the 3 way is located. Edited January 12 by DCB 1 Link to post Share on other sites More sharing options...
RMweb Premium ColinK Posted January 12 Author RMweb Premium Share Posted January 12 Thanks DCB, that woukd be much neater, I might do that when installing the points on the layout. Link to post Share on other sites More sharing options...
RMweb Premium ColinK Posted February 7 Author RMweb Premium Share Posted February 7 Three way points now installed on the layout. Unfortunatly the Gaugemaster CDU hasn’t enough grunt to switch the two Rails of Sheffield solenoid motors at once. But I discovered that DCC Concepts produce a high powered twin CDU which us cased and plugs directly into 240v. It’s a good bit of kit, and when you consider that it is mains powered, is good value for money. Superb service by DCC Concepts in getting it to me. 1 Link to post Share on other sites More sharing options...
RMweb Premium ColinK Posted February 28 Author RMweb Premium Share Posted February 28 The DCC Concepts CDU certainly has enough power to change several solenoid motors at once. However both three way points do not work as expected. While they will set the straight route, neither will set the left or right routes. Any suggestions on how to get them working properly appreciated. Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted February 29 RMweb Premium Share Posted February 29 I wonder if you have the green and black wires incorrect? In the photo you showed of your diode matrix, it's not clear what you have actually done. Perhaps a diagram would help. Link to post Share on other sites More sharing options...
smokebox Posted February 29 Share Posted February 29 (edited) The green wire, bottom right of the the tag board, doesn't appear to have anything connected to it? Edited February 29 by smokebox Link to post Share on other sites More sharing options...
RMweb Premium ColinK Posted February 29 Author RMweb Premium Share Posted February 29 Well spotted, the green wire wasn’t connected when I took the photo, but it is now. Link to post Share on other sites More sharing options...
DCB Posted March 1 Share Posted March 1 On 29/02/2024 at 08:34, ColinK said: Well spotted, the green wire wasn’t connected when I took the photo, but it is now. Did that cure the problem? 1 Link to post Share on other sites More sharing options...
RMweb Premium ColinK Posted March 1 Author RMweb Premium Share Posted March 1 Nope, I spotted the missing green wire before the points were installed. Link to post Share on other sites More sharing options...
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