I searched through most of this forum for an answer to my question but haven’t found one. So, if my question has been answered elsewhere please let me know.
Anyway, I am in the process of installing my roundhouse track. My question, what is the best way to cut the power to those tracks? Do I use a SPST/DPDT switch for each track or a SPnT switch(where n is the number of tracks), one pole for each track radiating from the turntable that is not on the mainline? My mainline is DCC. If the SPnT is the way to go, where is the best place to find such a switch?
Either solution will work. The DPST/SPST for each track will allow you to have more than one locomotive with lights on or sounds emanating at a time. I would recommend DPST to avoid problems if you ever use more than one power booster to power the roundhouse tracks. The SPnT prevents more than one track from ever being active at the same time, which may be unnecessary interlocking with DCC.
Either one will work. You only need SPST, and you only need to control one rail. The SPnT that you refer to would be called a “rotary switch” and should be available from any electronics supply place.
I installed SPST switches, one for each “spoke” off my turntable, on my control panel. I “temporarily” wired all the tracks on while installing the turntable and roundhouse, and so far I haven’t bothered to run the wires back through the panel, and I may never do this. Like you, I’m running DCC. With DCC, I don’t see any reason to have individual shutoffs for the tracks.
I’ve got several GP-9’s and F7’s, all in Milwaukee colors. When I’m looking for one of them, I use the “airport parking lot” trick of flashing the headlights on and off. For that to work, of course, the track power must be on.
Lots of answers in mind then I noticed the magic letters “DCC”… so the only thing that I can suggest is that if you have tracks where you can’t see that the loco has reached the dead end… then put in either infra red detection or a reed switch (to act as a treadle) to knock the power to that track off until you stop the loco and then re-set the power if/when you want for sounds and/or to move the loco again. An auto cut-out and manual reset saves forgetting and hitting the back of the house and/or starting up again when you don’t mean to.
Hope this helps.
That said… any chance of some circuit diagrams from those who now please??? TIA
I had a layout as a teenager and am now building another. I’m 60 now. So I’ve got several DC powered locos that I really don’t want to get rid of and my convert to DCC later. I have also got my track power set up for DCC or DC. So I will need to be able to cut the power off to my DCC locos when running my DC locos. Maybe too complicated but it keeps me busy.
That’s exactly why I installed those SPST switches in the first place. I’m 59, and I have some locos from my teenage layout that I’d planned to run as DC engines under DCC.
But, I found that those old timers didn’t run very well, either as DC engines or even with decoders installed. They were mostly cheap Athearn BB’s, even some of the rubber-band-drive models, so I converted them to eunuch engines and now I tow them in consists. On the bright side, I did get one of them (a geared Athearn F-7) to work well enough with a decoder so that I can actually use it.
I used a rotory switch to control power to my roundhouse tracks. I run DC, so I only wanted to power one track at a time. I also made sure to leave one pole open, so the switch would have an “off” position.
Assuming you want to put the rotary switch at the turntable in the panel schematic, standard rotary switches turn in 30 degree increments, fine for the original Atlas turntable but less than wonderful for longer tables with less angle between tracks. While a rotary switch is good for interlocking purposes, a separate power switch in each fan track is just as good.
Since the switches would logically be thrown after stopping (or before starting) the loco, they can be the least expensive SPST’s you can find. A DPDT switch would be gross overkill.
On my working module, the isolated track sections where I might want to kill a locomotive are powered through miniature SPST toggle switches. I considered using miniature slide switches (the ultimate in cheap) but the toggle switches are easier to check for position.
Chuck (who usually buys his electrical switches at Radio Shack)
Prior to going to DCC, I used a 32 pole rotary switch I got from RS. Each RH track was wired clockwise from the closest lead to the switch as one and all right rails were ground comman. My TT was wired using the least expensive DC power pack with the AC to drive the TT and the DC to provide the bridge rail power. Once I went to DCC, I found that i only need to replace the rotary with a DPDT switch for the first tack which I use as a Program track and RH track because the RH & TT are laid on the inside corner of my layout. The remainder of the RH tracks are just wired as one power block or booster for the yard service area. Once I out an engine on a RH track I delete it from the controler until I need to pull it out again. The DCC saved me about 25 feet of wire & 42 SPST switches used on the DC Set up. If you are still wanting to use cutout for those tracks, the rotary switch will still work as it has 64 tabs associated to the 32 positions. the upper 32 are for + side, The Lower 32 are for Neg side. A rotary switch will be about a 2" dia Knob on your facia and about 3-4" deep behind it. I still keep the TT set up with the DC power pack and leave my decoders set to run both DC or DCC because of cost of other electronics options and to control my layout are not justified on one that works as is. If I build a new layout thenI will buy an entire new setup such as Walthers now offers. Hope this was of some help.