Wag Posted November 12, 2018 Share Posted November 12, 2018 Help I am building a small branchline on 6 x 1.5 using DC as a side project, six points with peco and Hornby points mixed with respective point motors. Gaugemaster control with stud and probe. Points wired tested and all working. Just looking forward to doing some modelling but when testing again but the power seems to drain away and there is not enough current to shift the points.. I have disconnected the link to the rails and still the same thing happens. Any thoughts on what has happened and how this can be solved. Many thanks Link to post Share on other sites More sharing options...
Grovenor Posted November 13, 2018 Share Posted November 13, 2018 What is the power supply? Does it include a Capacitor discharge unit (CDU)? Regards Link to post Share on other sites More sharing options...
RAF96 Posted November 13, 2018 Share Posted November 13, 2018 Using a stub and probe, just make sure when you lay it down that the probe isn’t touching anything that could act as a common earth. Many folk put their probe in an insulated parking ‘stand’. Use of a CDU will take some of the risk out of this happening. Rob Link to post Share on other sites More sharing options...
Brian Posted November 13, 2018 Share Posted November 13, 2018 (edited) Assume your using the 16volt AC output for the point motors? Also as previously suggested, the addition of a single CDU wired after the power supply and before the probe will benefit the solenoid motors operation. It will also prevent accidental motor coil burn out. Wiring from the Stud to the motors coils should be 16/0.2mm equipment wire (or 0.5mm2 or 20AWG) as a minimum and the same size of wire used for the motor returns too. Increase the return wire size if two or more motors operate from one stud e.g. a cross-over pair of points. Basic idea is here... https://www.brian-lambert.co.uk/wpimages/wp51398928_06.png Edited November 13, 2018 by Brian Link to post Share on other sites More sharing options...
Wag Posted November 13, 2018 Author Share Posted November 13, 2018 Thanks for the responses, I am using single controller gaugemaster but without cdu. I have checked to ensure no earthing only two points connected together for operation. The frustration is that is was working and now not. I will get a cdu, this was meant to be a little project using old track and and bits and bobs hanging around! Link to post Share on other sites More sharing options...
Pete the Elaner Posted November 13, 2018 Share Posted November 13, 2018 Its strange that it has stopped working. You should see a massive difference with a CDU. You only have to buy one for the whole layout (or if you like electronics, building one is quite an enjoyable project), so it will not be a massive outlay. I helped a friend build a layout with SEEP motors. These wouldn't throw at all without a CDU but have been perfectly reliable since we fitted one. Link to post Share on other sites More sharing options...
RMweb Gold john new Posted January 5, 2019 RMweb Gold Share Posted January 5, 2019 Thanks for the responses, I am using single controller gaugemaster but without cdu. I have checked to ensure no earthing only two points connected together for operation. The frustration is that is was working and now not. I will get a cdu, this was meant to be a little project using old track and and bits and bobs hanging around! I am currently doing the same, i.e making a layout out of the bits and bobs lying around, although I will need to buy point motors. Was planning to just use the 15v AC output from my Gaugemaster Combi as there are only four points on the layout and all are singles, changed one at a time. (No route setting with multiples) Thanks for the tips above giving confirmation of needing a CDU as I wasn't sure I needed one with single points. Will have to see what is still inside the control panel box from the last layout (Now scrapped) before buying one as I haven't stripped that out yet. Link to post Share on other sites More sharing options...
Butler Henderson Posted January 5, 2019 Share Posted January 5, 2019 I am currently doing the same, i.e making a layout out of the bits and bobs lying around, although I will need to buy point motors. Was planning to just use the 15v AC output from my Gaugemaster Combi as there are only four points on the layout and all are singles, changed one at a time. (No route setting with multiples) Thanks for the tips above giving confirmation of needing a CDU as I wasn't sure I needed one with single points. Will have to see what is still inside the control panel box from the last layout (Now scrapped) before buying one as I haven't stripped that out yet. A CDU is pretty much a necessity - not just avoiding coil burn out but also cutting down on the loud buzzing that can occur on AC and replacing it with a noticeable thud as the point changes (hence acting as a confirmation that the point has changed). To avoid the thud the solution is not to use solenoid point motor but slow motion ones which use dc. Link to post Share on other sites More sharing options...
Butler Henderson Posted January 5, 2019 Share Posted January 5, 2019 (edited) Also a CDU is a pretty simple circuit that only uses a few components and can be put together very cheaply; take the circuit at http://www.thehobbyshed.co.uk/capacitor-discharge-unit for example - the LED and R5 are not essential, C1 & C2 can be combined as a single 4700μF capacitor and the 4 2k2 resistors can be replaced by single 2 watt 560R resistor. I have one that is years old using a 2N3055 transistor which is a big pretty indestructible metal cased one - its an ideal circuit for someone unsure of their ability with electronics and can be assembled with the components soldered to each other with heatshrink as appropriate. Edited January 5, 2019 by Butler Henderson Link to post Share on other sites More sharing options...
cliff park Posted January 5, 2019 Share Posted January 5, 2019 I think the mF on the diagram means μF, ie microfarad. So 4700μF would be correct Link to post Share on other sites More sharing options...
Butler Henderson Posted January 5, 2019 Share Posted January 5, 2019 I think the mF on the diagram means μF, ie microfarad. So 4700μF would be correct Yes, obviously in weekend not thinking mode when I typed the message so have edited it Link to post Share on other sites More sharing options...
RMweb Gold john new Posted January 5, 2019 RMweb Gold Share Posted January 5, 2019 A CDU is pretty much a necessity - not just avoiding coil burn out but also cutting down on the loud buzzing that can occur on AC and replacing it with a noticeable thud as the point changes (hence acting as a confirmation that the point has changed). To avoid the thud the solution is not to use solenoid point motor but slow motion ones which use dc. I have always found that the thud is an extremely useful audible confirmation the point has thrown. Link to post Share on other sites More sharing options...
DCB Posted January 11, 2019 Share Posted January 11, 2019 Cheap way is to rectify the AC through 4 diodes forming a bridge, should cost 40p, and put a 24 volt capacitor across the output. anything from about 4700μF to about 8000μF should do nicely. I use 22 000μF use anything much less than 24 volts as they can blow up! You can always buy a CDU unit which is £3 worth of compoments for £20 if you have cash to spare. Always discharge any capacitors or CDUs when you switch off the power, they store power for weeks otherwise. 1 Link to post Share on other sites More sharing options...
Pete the Elaner Posted January 11, 2019 Share Posted January 11, 2019 Cheap way is to rectify the AC through 4 diodes forming a bridge, should cost 40p, and put a 24 volt capacitor across the output. anything from about 4700μF to about 8000μF should do nicely. I use 22 000μF use anything much less than 24 volts as they can blow up! You can always buy a CDU unit which is £3 worth of compoments for £20 if you have cash to spare. Always discharge any capacitors or CDUs when you switch off the power, they store power for weeks otherwise. That's a bit crude but will work. It is crude because although it will give the initial kick you need, ideally you want the current to drop to prevent a large 'back emf' being generated when you open the circuit again (the sudden drop in current makes the magnetic field around the coil collapse, causing a voltage (emf) in the reverse direction) Just adding a resistor to the input will work but this causes the capacitors to charge slowly. There are more refined solutions which are easy to build. Mine cost me about £4 each. (Capacitors are a lot more expensive than resistors, diodes, transistors etc). These are rewarding if you like electronic kits. Gaugemaster's CDU often sells for £14, is very easy to install & there is no chance that you have soldered a component in the wrong place. Link to post Share on other sites More sharing options...
Ron Solly Posted January 13, 2019 Share Posted January 13, 2019 One of many CDU circuits http://www.talkingelectronics.com/projects/CDU-2/CDU-2.html#CDU-MkIIB Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted January 13, 2019 RMweb Premium Share Posted January 13, 2019 One of many CDU circuits http://www.talkingelectronics.com/projects/CDU-2/CDU-2.html#CDU-MkIIB A good circuit that works. But perhaps we should point out (sorry for the pun), that in kit form, it comes from Australia (Melbourne I believe - at least it used to be). Link to post Share on other sites More sharing options...
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