I’ve got a DC only n-scale layout. It is all Atlas code 80 track and remote turnouts. I may move to DCC but it won’t be for at least a year (looking to get a DCC system next X-Mas).
I’ve got 3 track blocks that I use 3 different transformers on. One is an old Tech II “nice” transformer while the others are the type that come with a “kit”. One is a Bachmann small ez-track transformer, the other is a really old one from the late 1950’s.
I use DC for the rails and all other parts I use AC. I’ve got a few remote switchs that trigger two turnouts at the same time, so one momentary atlas switch. My 1950 and Bachmann transformers will not throw two at the same time, they will only work against 1 turnout. My Tech II will throw as many as three (I only tested three).
My issue is every time I throw a switch my trains “bog” a slight bit. I’ve seen many posts regarding this issue but I’m having a hard time finding a solid answer.
I’m looking for an isolated transformer I can purchase, wire up all my AC gear (what will be several LEDs via a diode bridge, all my turnouts, some other lighting, etc). When it is all done and said I’ll probably have some momentary atlas switchs throw as many as three turnouts at a time I can’t figure out the amount of amps I’ll need for this.
Any advice?
EDIT
I forgot to ask this one, what current type would be “best” AC or DC and why?
The turnouts are momentary - they are only on for about a second or less - but they can draw 2-3 amps each while on. Throwing 2 turnouts at once doubles the load.
LEDs use about 20 ma each. Light bulbs depend - could be anywhere from 50 to 300 ma each.
Best solution: As you inferred, use a separate power supply for the turnouts. I also strongly recommend a capacitive discharge unit (CDU). These are very simple to build (see http://home.cogeco.ca/~rpaisley4/CDPSU.html), or can be bought commercially. The CDU delivers a brief shot of high current from the stored energy in the capacitor(s) - exactly what is best for twin coil switch machines.
Even with a CDU, the capacitor recharge current can be a significant drain and cause lights on an under-powered transformer to dim slightly. Without a CDU, throwing the turnouts WILL cause the lights to dim momentarily if they are connected to the same transformer (unless it’s a mighty big transformer). A one amp power supply is probably good enough to recharge your CDU.
I further suggest using a separate transformer or wall wart for lighting to prevent dimming during turnout operations. If your total lighting load is small (less than 1/2 amp), you could power them off the MRC power pack accessory terminals without any problems. The LEDs would still need a diode bridge and resisitors in series with each diode. Since the lights are a steady, but small, load they will not impact operation of your locomotives from the same power pack (as long as total power drawn is within ratings).
Unavoidable as long as they are sharing the same supply. One will notice this in a house as well. All the current of the power station availble and the lights will still flitter a tiny bit when one turns on the vacuum, garbage disposal, or dryer.
The only real way to know would be to measure each thing and add it all up. They would also have to be measured on start up - a motor or coil will draw more current when first activated (because they have coils) than it will under a constant load.
However as I mentioned above even getting enough current isn’t going to make the lamps not flicker. The real way to do this would be to have a separate supply for the switch motors and the lamps.
In general AC is easier to distribute over long distances. As we don’t have long distances, for our tiny purposes it doesn’t matter. AC supplies are generally cheaper because they doet have to have the rectifiers for converting it to DC.
Solenoid switches should never be powered off the any power pack operating trains. I have seen trains slow down momentarily when solenoid swithces are thrown that are powered off an MRC 6200 power pack.