I'm certain it's been asked before but I'm not searching for the right things. I know about running block signals to run two trains with one transformer. But can you run two connected loops (inside and outside loop) with different voltages? I want my inner loop with my freight train to run slower and my outer passenger loop to go faster. The thing is those loops are connected by switches, so I don't know if it's possible.

Thanks guys!

Yes, just isolate the center rails with insulating pins, where the two loops connect with the switches.

One handle of a transformer powers the inner loop, and the other handle powers the outer loop. Just be cautious when running a train from one loop to the other, because it might speed up and do something naughty.



Click and help if you can

quote:

can you run two connected loops (inside and outside loop) with different voltages?

Yes

quote:

The thing is those loops are connected by switches, so I don't know if it's possible.

The center rail needs to be insulated. If you are using two transformers, they need to be in phase.
See this thread.

As suggested above, insulate your center rail at the crossover turnouts.

When crossing from one loop[power district/throttle] to the other set the voltage on your two different throttles as near the same level as possible. Substantially different voltage rates between the loops can cause circulating currents in the system.[having panel volt meters connected for each loop or district is helpful for equalizing the voltage].
Remember, one of the locomotive's pickup rollers is located in each power district[loop]as they straddle the insulated center rail.

You can get more complicated and install a "Block Power Controller" which essentially switches control of both power districts to one throttle[and voltage]for the time the train is negotiating the crossover. More simply, a 10 amp toggle switch can do the same.

I have no problems using Z4000s. Just electrically separate the two loops with insulating pins at the crossovers (and be sure you are using a "common ground' with both loops). No problems running a train from one loop to another either (although I do try to match voltages for operational reasons).

I have three loops, the two outer loops are my mainlines and the inner third loop is for switching. I have switches so a train can travel from the inner third loop all the way to the outer first loop. Each loop has it's out throttle control, I have three Lionel KW's, and I used an insulating pin on the center rail between the two switches that connect each loop.

Below is a shot of my track plan and when you see a set of switches that connect each loop there is an insulating pin between the two switches, I circled in red and put red dots where the insulating pins are. And, all of the transformers are phased together and there is one ground to all of the outside rails. Hopefully this makes it a little easier, it can be confusing. Good luck, email me if you have any questions.



Paul

He said "can you run two connected loops (inside and outside loop) with different voltages?"

If you mean one transformer to two connected loops, with different voltages, the answer is no.

But this is what command control is for -- get yourself TMCC or DCS. One voltage goes to the track, and the engine's internal electronics alters the voltage to get a different speed.

Without command control you can still go old school, you will have to isolate, using plastic pins, the two loops, and then use two transformers.

You might be able to use a bridge rectifier hooked up 'weird' to drop the voltage, but you will have to play with how many.

Again, in my opinion, this is what command control was invented for.

Paul is basically doing what I want to do. I'm using an old school ZW so I have 4 throttles available which is basically the same as Paul having 3 KW's.

quote:

Originally posted by SolarEclipse2:
But can you run two connected loops (inside and outside loop) with different voltages?
Thanks guys!

Solar - Here is "my two cents worth". ANYTIME you have a voltage differential between two adjoining sections of track (different blocks), a fault current is produced when dual pickup rollers span these tracks. The result (however small depending on the difference in voltage) will cause arcing across the pickup rollers & possibly LONGTERM cumulative damage to the surface of the rollers, & I am not sure of this one, but also damage to the transformer throttle contactors (pitting).
Sorry I don't have a solution to offer, just a friendly warning. I sure others here have solutions. FYI.
Tom B

Keep voltage the same

To make a freight run slower on conventional I run:

Freight diesel outside longest track
1 or 2 dummy's (good weight)engine, 8-14 cars maybe a couple are illuminated like searchlight or radioactive and then caboose.

Passenger steam 1 box car 4 passenger inside shorter track

or buy a dcs system. Its a lot more fun.

I'm going to keep running conventional. My passenger is my Santa Fe 218 diesel, 220 dummy and 4 passenger cars. Freight is either 2035,2037, or 5412 steam locos and any number of other cars.

I just want to do this until I can set up block signals. My train my train makes I around. He small loop just on time to interfere with the one coming around the bigger loop.

A number of guys have said doing the loops as described here isn't a problem for them so I can't imagine it's going to be a problem for me.

Yes you can run two loops at different voltages with one single handle transformer like an LW. The loops need to be separated with an insulating pins and phased.

Install a heavy duty resistor in the feed to the slower loop. This can be a wire wound resistor with an adjustable slide to vary the resistance to allow adjustment of the speed. I do not know the size you will need.

I use such a resistor to operate two trains on one loop using an isolated outside rail as a switch to control a relay to kill a section of track to keep the faster train from over running the slower train. But I do not want the section to be completely dead as the e unit will cycle the train into reverse. So a resistor is used to keep 3 volts on the section and keep the e unit from operating and yet still stop the train. Works like a charm and you can find a resistance to give you the slower speed loop you want. My resistor is 6 inches long and 1 inch in diameter with an adjustable slide to move up and down the resistor to change the voltage.

Charlie