I have just added another run of 12vdc Reg from one wiring block to another. I was thinking of adding another. How many building bulbs can I run safely or does it matter?
I am trying to get rid of the rats nest under the layout.
Harold
typically not a question of safety.
it's the amount of current drawn by the bulbs and capacity of the power supply
greg - Philadelphia & Reading / Reading
It is a 12vdc Wall wart.
what is the max power supply current (A, amp, ma) rating?
what type bulbs are you using? do you know their current rating?
how many bulbs?
Each power supply should be connected to its own lighting bus do not parallel them on the same bus.
I recommend installing a fuse for any of these supplies. They typically do not have circuit breakers and will not shut down and reset. They normally have a built-in one time fuse, non-replaceable. When it blows, you've got an ugly paperweight.
If you have a 5 amp supply, that's 5000 milliamps. If you use 30 milliamp incandescent bulbs like me, that gives 166 bulbs before you reach capacity for that supply. I would give it 100 bulbs or less, both to be safe and to let you use a smaller fuse for safety.
It takes an iron man to play with a toy iron horse.
MisterBeasleyI recommend installing a fuse for any of these supplies.
One thing to consider is at 12V DC your building lights are going to be "full blast" - very bright. I find reducing that to mayb 6-8 volts looks a lot more realistic, and the bulbs last much longer at lower power.
I power building lights and streetlights with old DC train powerpacks using the output(s) meant for the rails. You can often get like MDC Tech II or Tech IV dual-power units for a decent price at model rail fleamarkets.
Otherwise, you can use resistors for each light to reduce the power to them, or add a variable rheostat of some kind. Radio Shack hashad a 25-ohm, 3-watt one designed for low-power that only cost a few bucks. If you can't find that, I'm sure many similar ones are available online now.
wjstix One thing to consider is at 12V DC your building lights are going to be "full blast" - very bright. I find reducing that to mayb 6-8 volts looks a lot more realistic, and the bulbs last much longer at lower power.
I use a 12 VDC supply for my lighting bus but I use 16 volt bulbs. This has the same effect. I basically never burn out incandescent bulbs.
As most of you know I’m an incandescent bulb freak. I use 12 volt Grain of Wheat bulbs, 50ma to 100ma. I have hundreds of bulbs and they take a lot of current.I operate my 12 volt GOW bulbs at about 70% or around 8 volts. Incandescent bulbs operating at 70% last forever and look very realistic for 1950s lighting. I can count failures since the 70s on one hand operating at reduced voltage. To get the 8 volts I use DC to DC Buck Converters. 12 volts in to the Buck Converters and adjustable voltage out. The Converters are rated for 8 amps ambient and 12 amps with a tiny fan for cooling. A is Current adjust V is Voltage adjust
I use one 12 volt power supply for my lighting source, my total 8 volt lamp load is running just under 12 amps with all bulbs on. The Buck Converters are voltage and current regulated from 1.2 volts to just under 11 volts using the 12 volt source.My single 12 volt 30 amp power supply supplies 12 volts input to several Buck Converters adjusted anywhere between 1.4 volts to 8 volts I have about 300 1½ volt micro bulbs (HO vehicle headlights) operating from a Buck Converter set to 1.35 volts drawing 4.5 amps. A second converter set to 5 volts to supply a dozen or so Arduinos. I made current drivers for the Arduinos to operate about 200 bulbs at 8 volts, about 12 amps total split on three Buck Converters. Total 12 volt current about 18 amps. Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California Turned 84 last July, aging is definitely not for wimps.