loop reverse and kaydee couplers

[gandy dancer#1]

HI its me again Couple of questions:Been reading, and not understanding why i cant switch wires on rerailer track and make train go oposite direction?? Everyone else states either have to use reverse on controller, or install ane exspensive reverse loop switch. isnt the track a simple dc circuit , pos and neg???

Need recommendations on kaydee couplers, running bachman ho set, cant sort out on their website which ones i need to replace what came on my set.

[ACY]

Most can be easily replaced with a Kadee #148, except for the front coupler on steam locos, and the passenger cars, which require long shank couplers, and the steam locos may require some manipulation/work to get the couplers in properly.
Also for you reverse section/loop, it is best to use an automatic reversing module if using DCC, if not you'll have to manually throw a switch each time it goes in or comes out depending which way it was thrown and which way you went in relative to that.

[Jim Banner]

If you are using DCC, it is actually ac on the tracks but you still have to worry about what happens in reverse loops.  Basically, as you go around the loop, what was the main line's right hand rail going into the loop becomes the left hand rail coming out of the loop.  So whatever its polarity (dc) or phase (ac) going into the loop, is now wrong when you come out of the loop.  You have to do something to correct that, or you will cause a short circuit.

With dc, you need a cross-wired toggle switch to change the polarity of the main line while you are in the loop.  With DCC, you can change the phase of the loop itself and a reversing module will do that in an eye blink.  If you have a simple reverse loop, that is, a reverse loop with only one way in and one way out, there is another way of wiring it that is cheaper than a reverser and works just as well.

If you want to get around the loop by switching the wires on the loop's rerailer section, you can do it by stopping the train in the loop, unplugging the feed to the loop, turning over the plug, and plugging it back in.  With DCC, which defines forward relative to the front end of the locomotive, that is all you would have to do.  With dc, which defines forward relative to the polarity of the track, you would also have to throw the reversing switch on your power pack.

If you are still having trouble with this, don't feel bad.  It is the thing about two rail wiring that confuses people the most.  What you might do is set up a reverse loop and try it out.

Jim

[jward]

re: reverse loop wiring on dc.

you can get around the need for a seperate reversing sitch for the loop itself by inserting a bridge rectifier between the power pack and the loop track. the ac terminals are connected to the power pack, and the dc terminals to the track. you will only be able to travel the loop one direction. if you wire the loop for clockwise travel, you won't be able to go anti-clockwise as the bridge will prevent you from reversing direction while in the loop. you will need to flip the reverse switch on the power pack while travelling the loop, and you'll then leave the loop with no problems.

bridge rectifiers are readily available in the parts drawers at radio shack. get one rated for at least 12 volts, and at least the current rating of your power pack. when i used them on my n scale layout, mine were rated at 5 amps, 120 volts ac, values which i was never going to come close to exceeding.

[gandy dancer#1]

HI: Solved my problem in changing direction on track, just unplugged conector on reriler moved it to other side of track and now everything runs in the other direction, guess im the dumb one here