arfaminit Posted May 19, 2015 Share Posted May 19, 2015 My Hornby C912 transformer unit is playing up One minute its ok then just stops working.. Measured the output at 16v a/c when ok but it drops to 7v a/c without warning Should I just bin it as its impossible to open ? Can't see any transformers (with the required 15v a/c output) available at all, other than Hornby's own .. Thanks Link to post Share on other sites More sharing options...
Brian Posted May 19, 2015 Share Posted May 19, 2015 Hi Is it cutting out / reducing its output with nothing connected to its output or only with the controller connected? 16 volt AC power supplies are hard to find in the wall plug in varity, so Hornby of Scalextric types may be the only option? Link to post Share on other sites More sharing options...
arfaminit Posted May 20, 2015 Author Share Posted May 20, 2015 Hi Is it cutting out / reducing its output with nothing connected to its output or only with the controller connected? 16 volt AC power supplies are hard to find in the wall plug in varity, so Hornby of Scalextric types may be the only option? To answer the above question, when the t/former stops working, I check its output with nothing connected, and get 7v shown on the meter. When I then check the current [if any] getting to the track, via the controller, its usually around 2-3v .. Link to post Share on other sites More sharing options...
Brian Posted May 20, 2015 Share Posted May 20, 2015 So initially you have a speed and direction controller connected to the PSU and possibly a train running too? Then if I understand correctly, after some while the power supply stops working or reduces its output? I assume after some time the PSU starts working again even if for only a brief period? Are you 100% sure it is the PSU cutting out and not the controllers internal over current trip operating? If the above is correct, I would be looking for the cause being possibly a short circuit or a current overload somewhere on the layout. Most of the Hornby wall plug PSUs are rated at 800milliamp and the controllers are renown for having low current internal trips, so any older loco - Hornby Dublo, Trix, Tri-ang or Tri-ang/Hornby etc running can cause the PSU internal trip to operate. Hornby and Lima Ringfield motors with weak magnets can also consume considerable current, but not actually place a full short on the rails Of course its equally possible the PSU has just gone defective, with age? What happens if no load connection is made to the PSUs output when its running correctly? Does it remain on or still turn off/reduce its output? Link to post Share on other sites More sharing options...
stewartingram Posted May 20, 2015 Share Posted May 20, 2015 When I then check the current [if any] getting to the track, via the controller, its usually around 2-3v .. Pedant mode, you are talking about 2 different things here. Volts = the "pressure" of electricity available to push it through the circuit. Current (measured in Amps) = the rate at which the electricity flows around the circuit when the latter is completed (ie switched on). So you can have a (say) 12v o/p available, but 0amps flowing because the circuit is not completed. Add a "load" (a bulb, motor, or whatever) and current flows, dependant upon the size of the load. (I could get more technical, but that is a layman's simple description). Stewart Link to post Share on other sites More sharing options...
meil Posted May 20, 2015 Share Posted May 20, 2015 My Hornby C912 transformer unit is playing up One minute its ok then just stops working.. Measured the output at 16v a/c when ok but it drops to 7v a/c without warning Should I just bin it as its impossible to open ? Can't see any transformers (with the required 15v a/c output) available at all, other than Hornby's own .. Thanks Buy yourself a Gaugemaster. Link to post Share on other sites More sharing options...
arfaminit Posted May 20, 2015 Author Share Posted May 20, 2015 When I then check the current [if any] getting to the track, via the controller, its usually around 2-3v .. Pedant mode, you are talking about 2 different things here. Volts = the "pressure" of electricity available to push it through the circuit. Current (measured in Amps) = the rate at which the electricity flows around the circuit when the latter is completed (ie switched on). So you can have a (say) 12v o/p available, but 0amps flowing because the circuit is not completed. Add a "load" (a bulb, motor, or whatever) and current flows, dependant upon the size of the load. (I could get more technical, but that is a layman's simple description). Stewart Thanks Stewart, I'm not at all technically minded but I see what you're saying .... Link to post Share on other sites More sharing options...
arfaminit Posted May 20, 2015 Author Share Posted May 20, 2015 So initially you have a speed and direction controller connected to the PSU and possibly a train running too? Then if I understand correctly, after some while the power supply stops working or reduces its output? I assume after some time the PSU starts working again even if for only a brief period? Are you 100% sure it is the PSU cutting out and not the controllers internal over current trip operating? If the above is correct, I would be looking for the cause being possibly a short circuit or a current overload somewhere on the layout. Most of the Hornby wall plug PSUs are rated at 800milliamp and the controllers are renown for having low current internal trips, so any older loco - Hornby Dublo, Trix, Tri-ang or Tri-ang/Hornby etc running can cause the PSU internal trip to operate. Hornby and Lima Ringfield motors with weak magnets can also consume considerable current, but not actually place a full short on the rails Of course its equally possible the PSU has just gone defective, with age? What happens if no load connection is made to the PSUs output when its running correctly? Does it remain on or still turn off/reduce its output? Cheers Brian, I can't say if the controller itself is at fault as obviously that's only working when the PSU is properly working, if you follow me..or have I missed something ? I have been running a 1980s Intercity 125 with a ringfield motor but its always very slow to get going, and has now packed up entirely.. Also a late 80s or early 90s Hornby King 4-6-0 with tender driven ringfield, which runs well but keeps de-railing on points...[peco or Hornby!] The most reliable is an oldish Hornby 'Jinty' 0-6-0 which flies round most of the time, but looks rather boring compared to the others ! Give me strength Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted May 21, 2015 RMweb Premium Share Posted May 21, 2015 Cheers Brian, I can't say if the controller itself is at fault as obviously that's only working when the PSU is properly working, if you follow me..or have I missed something ? I have been running a 1980s Intercity 125 with a ringfield motor but its always very slow to get going, and has now packed up entirely.. Also a late 80s or early 90s Hornby King 4-6-0 with tender driven ringfield, which runs well but keeps de-railing on points...[peco or Hornby!] The most reliable is an oldish Hornby 'Jinty' 0-6-0 which flies round most of the time, but looks rather boring compared to the others ! Give me strength Maybe the HST has caused an overload & has damaged the controller or power supply? Certainly the sluggish performance suggests something was wrong. Link to post Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.