Jenny Emily Posted October 5, 2011 Share Posted October 5, 2011 I've done a quick search but can't find anything. Can anyone tell me whether I should be wiring each coil in series or parallel on the point motors in order to throw several points with one switch and a CDU? I have a complex scissor crossing and I want all four points in it to switch together off one switch. I'm thinking probably in series, but I'm not 100% and it's awfully cramped under the baseboards for soldering more than I have to! Thanks in advance. Link to post Share on other sites More sharing options...
smokebox Posted October 5, 2011 Share Posted October 5, 2011 Parallel Link to post Share on other sites More sharing options...
RMweb Premium Kris Posted October 5, 2011 RMweb Premium Share Posted October 5, 2011 For firing multiple points at the same time you will be wanting a CDU. Link to post Share on other sites More sharing options...
Brian Posted October 5, 2011 Share Posted October 5, 2011 Hi Have a look here...http://www.brian-lambert.co.uk/Electrical.htm#Point%20Motor%20Wiring. You will need to scroll down a bit, but you will see examples of solenoid motors wired singly and in pairs etc. A CDU will be a great benefit too - CDU is a Capacitor Discharge Unit. Example http://www.gaugemaster.com/item_details.asp?code=CDU&r=1 Normally only one CDU is needed for the whole layout. It is wired after the power supply and before the first point operating switch and motor. Link to post Share on other sites More sharing options...
Jenny Emily Posted October 6, 2011 Author Share Posted October 6, 2011 Hi Have a look here...http://www.brian-lam...Motor%20Wiring. You will need to scroll down a bit, but you will see examples of solenoid motors wired singly and in pairs etc. A CDU will be a great benefit too - CDU is a Capacitor Discharge Unit. Example http://www.gaugemast...sp?code=CDU&r=1 Normally only one CDU is needed for the whole layout. It is wired after the power supply and before the first point operating switch and motor. Thanks for the replies. Thanks for the link - that website is helpful. I already have a CDU - my clunky sentence structure in my original post seems to have made that unclear. Without a CDU my Gaugemaster transformers struggle to give the oomph to operate more than one PL-10 at a time. Link to post Share on other sites More sharing options...
RMweb Gold Donw Posted October 6, 2011 RMweb Gold Share Posted October 6, 2011 I set a system for a friend which fired 6 six point motors in 0 gauge at once. I used switches to select the point settings and then a door beel push to fire the CDU. A second push would make sure that any sticky ones went over. They were wired parallel. Don Link to post Share on other sites More sharing options...
Suzie Posted October 7, 2011 Share Posted October 7, 2011 If your CDU is big enough you should be OK, but bear in mind you will need switches and wiring that will handle 16A DC. If the points all work together all the time, and your CDU voltage is high enough, you might get better results with paralleling up two pairs in series - but parallel with big switches and fat wire will guarantee success. Link to post Share on other sites More sharing options...
Pete the Elaner Posted October 8, 2011 Share Posted October 8, 2011 If the points all work together all the time, and your CDU voltage is high enough, you might get better results with paralleling up two pairs in series - but parallel with big switches and fat wire will guarantee success. Then you would have to ensure all coils are paired in series. I assume that the points would need to throw together in 1 direction only but individually in the opposite diection. If so, then series would not be an option. You would either not have enough voltage to throw those in series, or too much for singles which wuld cause failures. Gaugemaster CDUs are rated for 6 points IIRC so you should be fine. I don't see why you cannot connect 2 CDUs on parallel. You won't increase the voltage (so you won't overload anything) but you will have more charge available wihch will help power more motors. Link to post Share on other sites More sharing options...
Jenny Emily Posted October 9, 2011 Author Share Posted October 9, 2011 Thanks everyone. I spent many hours yesterday undertaking what has become my least favourite modelling activity (soldering above my head in the cramped under baseboard environs) but parallel has worked fine. So far the portions of the junction wired have at most three points changing together off any one switch, and the CDU and wire has been fine. I'm using wire that is identical to the type sold by Gaugemaster in small coloured reels. I found that fixing two screws into the underside of the baseboard by the points, then soldering all the wires from the points to these then one set back to the switch worked great. It keeps the lengths of wire to each point identical, neatens up the baseboard underside a little and makes potential fault finding a little easier. One thing also to remember is that the CDU holds a charge even after the transformer is switched off. I switch a set of points at least once after the transformer is off to remove any charge and to stop me from getting a shock when adding more wires. Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted October 9, 2011 RMweb Premium Share Posted October 9, 2011 Thanks everyone. I spent many hours yesterday undertaking what has become my least favourite modelling activity (soldering above my head in the cramped under baseboard environs) but parallel has worked fine. So far the portions of the junction wired have at most three points changing together off any one switch, and the CDU and wire has been fine. I'm using wire that is identical to the type sold by Gaugemaster in small coloured reels. I found that fixing two screws into the underside of the baseboard by the points, then soldering all the wires from the points to these then one set back to the switch worked great. It keeps the lengths of wire to each point identical, neatens up the baseboard underside a little and makes potential fault finding a little easier. One thing also to remember is that the CDU holds a charge even after the transformer is switched off. I switch a set of points at least once after the transformer is off to remove any charge and to stop me from getting a shock when adding more wires. Good policy to try to keep the wiring as standard as possible. Best to use a common wiring scheme & prewired to a terminal block *On the work bench*. It means you spend less time underneath. Ah, did we forget to tell you that capacitors hold their charge for long periods - sorry There is actually a way around this. Wire up an LED across the output terminals with a suitable resistor (this resister needs a bit of experimentation to work out its value - much too low & the LED will disappear in a puff of smoke, too low & the capacitor won't charge properly (the LED & resistor will act as a shunt and reduce the output voltage. When you get it working correctly (perhaps around 10K ohms - can't remember exactly), it is lit when power is available and will discharge the capacitor when power is removed & will discharge it completely in a couple of minutes. Kevin Martin Link to post Share on other sites More sharing options...
RMweb Gold Donw Posted October 10, 2011 RMweb Gold Share Posted October 10, 2011 When working in the telephone exchange one chap found that a capacitor charged up to 80volts stopped people fiddling with things on his desk. Don Link to post Share on other sites More sharing options...
Ron Solly Posted October 11, 2011 Share Posted October 11, 2011 A LED with a 2.2K resistor in series, across the output will drain the capacitors after the power is turned off & will not affect the operation of the CDU. Link to post Share on other sites More sharing options...
Dukedog Posted October 11, 2011 Share Posted October 11, 2011 One easy way of increasing the ability of your CDU to throw more points is to place another capacitor in parallel with the one already fitted on the circuit board. As far as I can recall the Gaugemaster CDU uses 2x 2200mfd caps. You can either add a 3rd 4700mfd Cap OR replace the two 2200mfd ones for 4700mfd Make sure that the capacitors you use have a working voltage of at least 63V. If that won't throw your points then you have major problems! Don't worry too much about switch contact ratings either. Switch manufacturers usually quote the maximum current Breaking capacity of the switch. Using a CDU the breaking current will (or should) be zero as the capacitor is discharged before the contacts open. If you are switching lots of solenoids simultaneously then why not consider Transistor assisted switching? I can post a circuit if you are interested. Cheers Frank Link to post Share on other sites More sharing options...
RMweb Premium M.I.B Posted October 13, 2011 RMweb Premium Share Posted October 13, 2011 Great info - thanks. Will keep this one bookmarked. Link to post Share on other sites More sharing options...
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