George Hudson Posted June 9, 2011 Share Posted June 9, 2011 I am not very experienced with electrical matters and tend to plod forward with simple systems working from simple first principles. I thought it would be useful to link certain (PECO) point motors so that one switch would move two complimentary points at once e.g. facing or trailing points must always be set together. As the following pictures show, I have a simple control box (with CDU) which pushes out current to motors on a push to make basis with a common return. A dry run showed that with one motor connected (switch 17) this worked fine however when I attempted to connect a second motor (18) by simply wiring at the switch box (grey wires). Only one motor would work and sometimes two but one in only one direction. I can’t see why this is so; does anyone have any ideas? Many thanks in advance! Andrew Link to post Share on other sites More sharing options...
RMweb Premium Ray H Posted June 9, 2011 RMweb Premium Share Posted June 9, 2011 My first thought would be to try to make sure that the motors work in isolation i.e. connect the power and switch to one motor of the pair only and make sure that works. If it does, swap the motors over and re-test. If that works connect the first motor to the second (in parallel) and re-try. To my mind a failure at that stage tends to suggest that the CDU has a problem (assuming that the CDU was in-line when you tested the individual motors). Link to post Share on other sites More sharing options...
amdaley Posted June 9, 2011 Share Posted June 9, 2011 Hi Andrew. As has been suggested make sure that the point motors work one by one by themselves ok. The problem may be that your wire may not be thick enough to carry the amps that two motors need. 2 motors together will take a fair thump to move them.If you don't have any thick wire available then double or triple what you are using at present to test it out. Link to post Share on other sites More sharing options...
Gordon H Posted June 9, 2011 Share Posted June 9, 2011 As has been suggested make sure that the point motors work one by one by themselves ok. The problem may be that your wire may not be thick enough to carry the amps that two motors need. 2 motors together will take a fair thump to move them.If you don't have any thick wire available then double or triple what you are using at present to test it out. Something else to look out for... If one motor is noticeably further away from the switch than the other, the available current may well be hogged by whichever is nearest. The low resistances involved with this kind of solenoid driving circuitry often mean that the resistance of the wiring itself comes into play. Link to post Share on other sites More sharing options...
mjkerr Posted June 9, 2011 Share Posted June 9, 2011 What type of switch have you installed? From the CDU, are the two point motors wired in series or parallel I use a SPDT switch and common return across the switch, in effect wiring the point motors in parallel No such issues What type and specification is the CDU? What type and specification is the power supply? I am using two Gaugemaster CDU which claim to be able to operate up to six point motors The power supplies use the uncontrolled 16V AC 2A outputs Link to post Share on other sites More sharing options...
Crosland Posted June 9, 2011 Share Posted June 9, 2011 Solenoid point motors take a considerable peak current to move. A CDU works by releasing the energy stored in the capacitor as a short high current pulse. Much higher than you could get from the power supply input to the CDU alone. The more energy stored in the capacitor the more grunt you get to move the solenoid. The energy stored is proportional to the capacitance and the square of the voltage. There are three possible solutions: 1 Much thicker wiring in all parts of the circuit bewteen the CDU, motors and switches to minimise voltage drop caused by the high current 2 Increase the capacitance in the CDU. 3 Increase the voltage used by the CDU. e.g., going from 12V to 15V will give greater than 50% increase in energy. You may need to replace the capacitors with ones suitable for the higher voltage, so do 2 at the same time. Andrew Crosland Link to post Share on other sites More sharing options...
Suzie Posted June 9, 2011 Share Posted June 9, 2011 I think that the first thing to do is to put a meter on to the output of the CDU and measure the voltage. If feeding it from a 16V AC transformer you should see about 20V - 25V which should be OK. If the voltage is lower you will need to look at the CDU and it's supply. A squirt of lubricant on the motors is often necessary. Link to post Share on other sites More sharing options...
George Hudson Posted June 9, 2011 Author Share Posted June 9, 2011 Well thanks to everyone for the tips, I will work through them over the weekend. I think the wires might be too thin for what I am trying to do. - I am using 16v ac from a Fleischmann controller with a PECO CDU - each point motor works ok on its own through the switch circuit/control panel proper - I tried two other point motorstogether but not using the switch circuit ie just touching the contacts with a pulse from the CDU and this worked but of course the wire distances were much lower than those in my full control panel and cable connector set up I don't fancy changing all the wiring so perhaps I will abandon the interlocking idea and have a switch for each motor: I bought them in bulk anyway. I will "plod through the suggestions systematically. Thanks again, very much appreciated! Andrew Link to post Share on other sites More sharing options...
mjkerr Posted June 9, 2011 Share Posted June 9, 2011 I think the wires might be too thin for what I am trying to do. The wires look similar to mine, but appearances can be deceiving What gauge are they? I am using 16/0.2mm for point motors to switches and 32/0.2mm for power supply to switches On convesion to DD the 32/0.2mm wires will then be removed Link to post Share on other sites More sharing options...
George Hudson Posted June 9, 2011 Author Share Posted June 9, 2011 They are 18x0,1mm, don't ask why I chose them, the seemed to be the thickest on display in the model shop. Link to post Share on other sites More sharing options...
amdaley Posted June 9, 2011 Share Posted June 9, 2011 They are 18x0,1mm, don't ask why I chose them, the seemed to be the thickest on display in the model shop. Double up the cable between the CDU & the point motors & you should be fine. Link to post Share on other sites More sharing options...
RAF96 Posted June 10, 2011 Share Posted June 10, 2011 Hi All my point motor solenoids (some doubled up), which can be controlled via pc, analogue or DCC, are fed from a GaugeMaster CDU using standard 5m long pc type network cables (the shortest I had in the spares box) and they all work fine, so don't get too hung up on cable diameters, etc. Your problem is more likely to be poor mechanical alignment or electrical connection of the dodgy motor or it needs a bit of lube (switch cleaner not WD40). Rob Link to post Share on other sites More sharing options...
Crosland Posted June 10, 2011 Share Posted June 10, 2011 Hi All my point motor solenoids (some doubled up), which can be controlled via pc, analogue or DCC, are fed from a GaugeMaster CDU using standard 5m long pc type network cables (the shortest I had in the spares box) and they all work fine, so don't get too hung up on cable diameters, etc. Sorry, but this is just bad advice. Cable spec is exactly what you should get hung up on, whether for point motors or DCC busses. There will always be people who "get away with it" in their particular circumstances, just as many people get away without modifying electrofrog points for DCC or without checking wheel back-to-backs, etc., etc., ... Andrew Crosland Link to post Share on other sites More sharing options...
George Hudson Posted June 11, 2011 Author Share Posted June 11, 2011 Sorry, but this is just bad advice. Cable spec is exactly what you should get hung up on, whether for point motors or DCC busses. There will always be people who "get away with it" in their particular circumstances, just as many people get away without modifying electrofrog points for DCC or without checking wheel back-to-backs, etc., etc., ... Andrew Crosland The DCC busses are 13 amp domestic appliance wire so rather thick. The droppers however (almost one per yard of track) at the thin wire which I mentioned above. Will I get a problem with that and should I therefore rewire the droppers between track and busses (a real pain at this stage but if it is wrong I should bit the bullet before going further)? Andrew Link to post Share on other sites More sharing options...
amdaley Posted June 11, 2011 Share Posted June 11, 2011 The DCC busses are 13 amp domestic appliance wire so rather thick. The droppers however (almost one per yard of track) at the thin wire which I mentioned above. Will I get a problem with that and should I therefore rewire the droppers between track and busses (a real pain at this stage but if it is wrong I should bit the bullet before going further)? Andrew It depends how long your droppers are ? If 300mm/1 ft or less then you will be fine. If your droppers are longer than that I would consider doubling up. If you need to double up just cut the existing droppers about 6" or so below the baseboard & double up from there to there main buses. I know at this stage some things can be a real pain but if you do it right now you will bless the day in the long run. Link to post Share on other sites More sharing options...
RMweb Gold Dagworth Posted June 11, 2011 RMweb Gold Share Posted June 11, 2011 Are both motors the same? Make sure you haven't got one low current one and one normal one. Andi Link to post Share on other sites More sharing options...
George Hudson Posted June 12, 2011 Author Share Posted June 12, 2011 It depends how long your droppers are ? If 300mm/1 ft or less then you will be fine. If your droppers are longer than that I would consider doubling up. If you need to double up just cut the existing droppers about 6" or so below the baseboard & double up from there to there main buses. I know at this stage some things can be a real pain but if you do it right now you will bless the day in the long run. Tony I think I can get all droppers down to 6 ins or so and if necessary run a second or third bus. I quite agree about doing things properly and like many of us have learnt the hard way! Andrew psAndi, all the motors are identical (supposedly) and bought as a batch Link to post Share on other sites More sharing options...
amdaley Posted June 12, 2011 Share Posted June 12, 2011 Tony I think I can get all droppers down to 6 ins or so and if necessary run a second or third bus. I quite agree about doing things properly and like many of us have learnt the hard way! Andrew psAndi, all the motors are identical (supposedly) and bought as a batch Hi Andrew. Before you do anything,what length are your droppers now ? Your main bus wires should be fine as they are unless you have baseboards going off in different directions. What size is the layout & is it what we see in the photo ? Link to post Share on other sites More sharing options...
George Hudson Posted June 14, 2011 Author Share Posted June 14, 2011 Hi Andrew. Before you do anything,what length are your droppers now ? Your main bus wires should be fine as they are unless you have baseboards going off in different directions. What size is the layout & is it what we see in the photo ? The droppers are various lengths and the layout is an oval of about 2m by 8m and fed currently by a bus of domestic mains cable running the whole length and connected to practically every yard of flexitráck. I am going to get the point motors working first and then come back to the bus since I have had no real problems with it. I will simply go around and tidy and shorten connections where necessary. I have decided to abandon the interlocking idea and simply have a switch for each motor since this is easier than rewiring the whole layout and panel. In fact it only took me an hour to solder up and fit the extra switches in the control panel and all connections were already in place to be screwed together between the panel and the layout. If my too-skinny wire worked for two individual switches, it should work for the other 19. Fingers crossed. Andrew Link to post Share on other sites More sharing options...
George Hudson Posted June 15, 2011 Author Share Posted June 15, 2011 Hurrah, it works! Well actually not every point but 95% and I am sure that I can sort out the others. The main point is that the 1mm wire is good enough for the job. Apart from the main lines, all the other trackwork has yet to be fixed in place so after I have made the 5% work properly, I will fix the track and ensure that it is geometrically correct and, following this, turn the spagetti wiring into something better looking/unseen. Thanks to everyone who took the time to comment. Andrew ps those connectors are from Brawa and push together like oversized "d" connectors. Link to post Share on other sites More sharing options...
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