How can I connect a DPDT Switch or anything similar to the Digitrax DB150 to switch between the mainline and the programming track. Where can I purchase a reliable one. The manual doesn’t explain how to connect a DPDT switch, and I’m not used to wiring.
The DPDTswitch will have 2 rows of 3 terminals on the back. Connect the DB150 to the centre 2 terminals. Connect one pair of outer terminals to the mainline and the other 2 to the programming track. Get a switch rated at 5 -10 amps so you’ll never have to replace it.
You can buy a good quality DPDT switch from Miniatronics or any LHS that carries Miniatronics products. Also, Radio Shack carries a good quality DPDT switch.
I am not familiar with the Digitrax DB150, but if you are not familiar with wiring, you need to get up to speed before installing a DPDT switch between the mainline and the programming track.
The DPDT switch has six contacts in three sets of two, set up in a pattern like the 6 dots on a dice.
The top left contact is typically jumpered to the lower right contact, and the top right contact is typically jumpered to the lower left contact to form an X wiring pattern. Then, the top two contacts accept the wires from your power source and the middle two contacts provide the output. This is how a DPDT switch is typically wired.
I would assume that the power source in your case is the pair of wires leading from your command station to the programming track. If so, these two wires would be soldered to the top pair of contacts on the DPDT switch. The, the wires leading to the programming track would be soldered to the middle set of contacts on the DPDT switch. But, again, this is just my assumption because I am unfamiliar with the Digitrax DB150, so get some expert advice.
Also, be aware that DPDT switches come in three operating styles: an ON-ON switch that simply toggles one way or the other to route power, an ON-OFF-ON switch, called a Center Off switch, that disconnects power in the center position, and a Momentary switch that reverts back to the original position of the toggle after momemtarily applying power.
As I already mentioned, if you are not familiar with DPDT switches, get some expert advice so you don’t wreck your programming track or worse.
Rich
No Rich, your scheme is what is commonly used for DC. See Allantrains reply above.
Joe
Joe,
In my own defense, I am unfamiliar with the Digitrax product in question, but I posted a response out of concern that the DPDT switch might be misused.
That wiring scheme that I described is one that I use on my DCC-powered layout, but the source of power for the DPDT switch is the AC side of a transformer.
Hope that helps.
Rich
That is not how you wire the DB150. Some people uses a DPDT on the programming track to switch it between the command station’s program track outputs and main track outputs, but the DB150 does not have a seperate program track output. With the DB150, you don’t switch the program track at all, what you want to be able to do is turn off the rest of the layout so that when programming you do not program all of the locos on your layout, and this is shown in the manual.
Which is what Alan described. You connect the DB150 to the center terminals of the DPDT switch, one sde goes to your layout, the other side to an isolate program track. If you always remember to flip the switch before going into program mode, you won’t accidently program every loco left on the track.
You can also automate this, NCE seels an automatic switcher which is meant to use with the PowerCab, which also does not have a dedicated program track, but there’s no reason it shouldn’t work on a DB150 as well
–Randy
Exactly the way I have mine set up and it works just fine.
Not exactly. What you and Alan described allows you have either the program track on OR the rest of the layout on, but not both. What I was talking about, and is shown in the manual, turns the rest of the layout off when programming, but leaves the program track on at all times. This is the way most people wire a program track with the DB150 because there is no reason to have the program track off when you are operating, in fact, many people prefer to have it on so they can use it just like a regular spur.
Well for that you need a double pole single throw switch, but those are usually tougher to find, so you can use a DPDT. Wire the center terminals AND you program track directly to the DB150, wire one set of side terminals to the rest of the layout. When the switch is in one position, both the program track and layout will get power. Move the switch the other way and only the program track will have power.
–Randy