Hi guys...i have the 1300 railpower supply ( total output 7VA) and only used for lights on DC (about 16 lights).. ...heres the problem: When i have the dial too 55% lets say, the lights are too dim, i have too go to 80% in order to get that real affect for ligting..I do want to conserve power on the bulbs so they dont burn out quicker... I dont have LEDS just regular model power bulbs connected to the source... .... i dont want to purchase a walwart, i want too control the lights by the dialing method.....I am looking at the 1370 railpower power supply which has a higher VA: 18VA total power and 15 dc and 19 AC......... i guess this will resolve my issue? what do you think?
jmk3438 ....i have the 1300 railpower supply ( total output 7VA) and only used for lights on DC (about 16 lights).. ...heres the problem: When i have the dial too 55% lets say, the lights are too dim, i have too go to 80% in order to get that real affect for ligting.
....i have the 1300 railpower supply ( total output 7VA) and only used for lights on DC (about 16 lights).. ...heres the problem: When i have the dial too 55% lets say, the lights are too dim, i have too go to 80% in order to get that real affect for ligting.
And your problem is?
Seriously, I see nothing wrong with what you are seeing. The MRC 1300 does not appear to be overloaded, and the bulbs are operating nicely at a reasonable voltage.
The best way to determine if everything is operating correctly is to measure voltage and current out of the MRC 1300 under load, and know the ratings of your light bulbs. And consider the % numbers on the dial of the MRC 1300 as strictly nominal numbers which have little relationship to actual output. Chances are the MRC 1300 (and 1370) only puts out about 12 volts on the variable DC under full load.
If you have 16 light bulbs rated at 100ma and 16 volts each, then you can't expect full brightness from the power supply. You need 16 volts times 16 times 0.1 amps equals 25.6VA, and you have overloaded your power supply. Even at 12 volts, 16 100ma bulbs are going to tax your power supply (19VA).
OTOH, if you are running 50ma light bulbs at 10 volts for a decent lighting level, then you are using 8VA - still overloading the 7VA supply, but it will probably take it (likely your present situation).
Voltage determines the brightness of the bulb. You want to run light bulbs at 75%-90% of their rated voltage for longer life. The exact voltage is determined by what brightness is satisfactory to you. The sum of the current ratings gives you the total current of the load. Total current times operating voltage gives the VA (volt-amp) rating.
Fred W
I don;t think you are overloaded, what you are experiencing is more the inability of the 1300 to make fine adjustmens at the upper end of the throttle. You would probably be better served with a basic fixed voltage power supply, either wall-wart type or plug in. Wall warts in various voltages you cna get at Radio Shack, but a cheaper alternative is to check out the multitude of different power supplies found on eBay and sold as repalcements for various bits fo computer hardware. You cna get anywhere from 5 to 19 volts, If your bulbs are all 14-16 volt rated, a 12V supply should eb good, use a DC supply and if it's still a touch too bright add in some 1 or 3 amp diodes, which you cna get at Radio Shack. Each one adds .7 volt drop, so 2 in series would be 1.4 volts, etc. You can do the same thing using the 1300 as well, add the diodes and just run it at full throttle. With diodes, if you accidently flip the direction switch, allt he lights will go out, so just don;t hit the direction switch.
276-1101 is the 1 amo diode, which since the 1300 can;t put out 1 amp should be fine. You get 2 in a pack. Try 2, if that's not enough reduction try 2 more. 276-1141 is the 3 amp diode, over spec won't hurt anything and you'll be still ok if you add more lights and use a larger power supply. The nice thing about using diodes is that they won;t get as hot as resistors plus it doesn't matter if you hook up 4 or 8 lights, so long as the total current doesn;t exceed the diode specs - the drop will be the same. With resistors, you have to change the value every time you change the load (number of bulbs). A silicon diode drops .7 volt pretty much from no load right up until the current limit. I did somethign liek this on anold N scale layout I had, my lights were all 16V and I used the DC out of my old power pack to runt hem, with 4 diodes in series and it on full power, it gave a nice glow without glaring brightness, so I know it was somwhere under 16V (didn;t have a meter back then).
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Almost any old transformer will work for lighting. They are a dime a dozen at train shows. Even running them at 11 volts will greatly increase bulb life, and give you a nice lighting effect. Bulbs aren't that expensive. Just make sure they are easily accessable to replace.
jmk,
You don't mention what the rating of your incandescent bulbs are (mA & voltage); nor whether you have them wired in series or in parallel.
I'm with you on using the DC terminals and the dial to dial down the voltage on your bulbs in order to extend their life. I have a MRC Railpower 1370 and run my 12V bulbs interior and exterior lighting at ~55%, which are plenty bright enough:
I picked up a 1370 on eBay for ~$20.00 (plus S&H) and it has served me quite well.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
I am with the last responder, just get one or more transformers and split the power usage. I have one operating a turntable and some of my city lights and another running four oil wells and the rest of my city and yard lights. I like the effect I get with more than one power supply, I can make some lights brighter and some dimmer. Besides that, all that HO scale oil we are producing makes the lights inexpensive! You just want to make sure you have easy access to service them. I drill a fairly big hole under any building that gets lights, and will just set the lights in the bottom floor. For upstairs lighting I will build the roof removable.
Phil, CEO, Eastern Sierra Pacific Railroad. We know where you are going, before you do!
jmk3438.i have the 1300 railpower supply ( total output 7VA) and only used for lights on DC (about 16 lights).. ...heres the problem: When i have the dial too 55% lets say, the lights are too dim, i have too go to 80% in order to get that real affect for ligting..I do want to conserve power on the bulbs so they dont burn out quicker... I dont have LEDS just regular model power bulbs connected to the source... .... i dont want to purchase a walwart, i want too control the lights by the dialing method.....I am looking at the 1370 railpower power supply which has a higher VA: 18VA total power and 15 dc and 19 AC......... i guess this will resolve my issue? what do you think?