I'm working on my first permanent HO layout. It is a 9x16 around the room shelf layout in HO. My DCC system is a Digitrax Super Chief. I also have available a MRC Tech controller with dual controls and accessories ports as well as a couple of 5 amp wallwarts. I want a lot of lighting and accessories on the layout. I was thinking that I would only use the DCC power for running trains.
I would like three different busses, I think. One for lights on all of the time. One for lights that go on for night running and one to support electrical accessories like train crossings, sound modules, etc. Does this approach sound reasonable? I was thinking that I could use the MRC Tech pack for the two lighting busses and the wallwart for the third. How can I tell when I'm reaching capacity on any of the busses? I will be using a combination of bulbs, commercial HO lighting products and LEDs. Any help would be appreciated. Thanks.
Tim Fahey
Musconetcong Branch of the Lehigh Valley RR
Each 5 amp wall-wart is probably more powerful than the Tech dual power pack.
Best bet especially with wall warts is to use a fuse or circuit breaker. A breaker is more convenient, no runnign out of fuses after allt eh stores are closed, but the idea would be to fuse the bus to somethign under the full load, so the fuse/breaker trips before the wall wart gets damaged. You'll know you reach the limit when the fuse blows.
If you know the ratings on the accessories you are connecting, if all wired in parallel on a given bus, all you to is add up the currents, and keep it to no more than 75% of the rating of the power supply. Say 10 street lights with 30ma bulbs, that's 300ma total. 1 amp is 1000ma.
Technically that should be 4 buses - the 3 for lights and accessories, plus the track power bus.Definitely run nothign else off the track power except the track. Otherwise you're wasting booster power, plus if a train derails and shorts it all shuts off. A 5 amp wall wart is cheaper than a 5 amp booster and power supply, plus light bulbs don;t need DCC signals.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Thanks Randy, I am actually trying to describe 4 busses = 1 track and 3 lighting accessories.
Thanks Randy.
I am also building a short shelf layout,and will require lighting ect. i was going to use christmass led sets, with batts but will go the wall wart way now.
Many thanks for all your help in thepast and a Happy New YEAR to all on the forum, and aspecial thanks to TIM for raising it.
Regards
Patrick
LIONS go for brute force with their power systems.
For Aux Power, the LION uses two 5 W transformers and two 15 AMP rectifiers. The (-) pole of the first rectifier is connected to the (+) pole of the second rectifier and this is connected to the building GROUND. This yields +12v dc; -12v dc; and zero volts (ground). Or 24 volts across the (+) and (-) connections.
In the tower, micro-switches send either (-) [normal] or (+) [reverse] current to the Tortoise Switch Machines. The same bus goes around the entire layout. and lighting is connected to GROUND and +12v dc. Sometimes the -12v dc is selected for use as the common in the case of 24 volt relay coils of which I have hundreds from surplus.
The LION does not have a "night" circuit since him runs subway trains inside of tunnels. The lights are on all of the time. Now think it through, I am sitting in my office typing this reply to you. It is 11:05 AM Mountain Standard time, the sun is shining outside. Guess what? MY LIGHTS ARE ON!
LION says... Leave the lights on and simply turn the room lights off at night.
Am I wrong? Go visit Times Square any time of day! Are the lights on? You betcha!
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
Rail yards don't leave their floodlights on all of the time, nor are street lights, security lighting outside buildings are only on at dark in many instances too. Those are what I want on my separate buss.
Back in the day we had a bank of like 8 toggles to control lights on the layout, so different things could come on at different times - street lights, house lights, yard floodlight tower, lights on the ski slope, etc.