I appreciate my question is elementary.
What is the simple way to reduce track power used to light buildings to where the bulbs are illuminating at 10 volts for long-life? There is an electrical shop nearby – Radio Shack is gone – what would I look for and how to recognize it. My guess is an item called a voltage regulator - not a rheostat.
Thanks,
Wendell
I’d recommend using the power supply for Malibu Outdoor Light Systems. It operates at twelve volts, is waterproof, and won’t steal power from your train.
I’ll second that !
Yes, you would be best served with a separate power supply.
But, you are correct, a voltage regulator would be what you are after.
Another option you might want to play around with if you understand wiring fairly easy is try tying some of the lights together in a series connection.
This is something I am experimenting with on my own layout as I am still on the fence of which way I want to go with lighting my buildings.
Anyway, if you take even just (2) lamps wired in series you will decrease the light output out of them in half, the only issue is if one lamp fails they both will go out… But with them seeing half of the voltage they would normally get they (using just 2-lamps in series) should last a real long time.
But, with using track voltage, if the track voltage varies, as in DC power, then lights without regulation will dim or go out. Of course lights even with regulation, will go out when the train stops.
If this is from DC track power (not explicitly stated), and the track power is varying, you want to do it one way.
If it is from fixed DC track power, you would do it differently.
So, just to be clear, which is it?
Greg
If DCC powered and buildings have large bulbs the it is a big drain on the digital system esp if the system is 5 amps.
Definitely run a separate power source and just add a resistor (I used 3 ohm 10 watt) in series with the power source to drop a couple of volts no regulator needed, no fancy electronics, no heat sink.
I did this with a outdoor lighting system and used 4 watt bulbs in the houses. Works great and has been in use for many years.
Also, replacing incandescent bulbs with LEDs will greatly reduce the drain on ANY power supply. They only need 3V to come on, but need to have the current limited or they’ll burn out faster than you can turn the power off. Using a resistor or (preferred by me) an LED driver will allow most any number of LED to be powered without any further calculation. I’ve got a printed circuit (photos in the photo gallery) that show one. Converts either AC or reversing DC to one way, limits current, and powers any number of LEDs. I used them originally in my passenger carss, but now use them where I’ve got a bunch of LEDs lighting buildings.
I’ve been using the Malibu light system outdoor since 2004 and its still going strong . I use a mixture of 12 volt bulbs and LED’s . Whats also nice is it has a timer to turn it off and on .
Still holding my suggestions until I hear from Wendell on fixed or varying track voltage, and what kind of control system.
Greg
Wendell Hanks said:
I appreciate my question is elementary.
What is the simple way to reduce track power used to light buildings to where the bulbs are illuminating at 10 volts for long-life? There is an electrical shop nearby – Radio Shack is gone – what would I look for and how to recognize it. My guess is an item called a voltage regulator - not a rheostat.
Thanks,
Wendell
Radio Shack is not gone and the three near me are doing business as usual. But Orvac Electronics is on Orangethorpe in Fullerton and they have about everything you could think of, as well as knowledgeable people behind the counters.
Assuming you want to reduce the typical 12-20 volts used to run the trains down to about 10 volts (as you inferred in your post), you could use a voltage regulator. You can get 10 volt, 2 amp regulator semiconductors though Goldmine Electronics, and (10 for $4.00), and 9 volt regulators should be even more readily available. Or you can use an adjustable voltage regulator. You can buy this by the component and solder it up (a simple schematic is usually on the package), but Orvac may have some ready made units that could fit the bill.
It would be cost prohibitive/unnecessary to have a separate regulator for each structure, but you need to be careful not to overload the regulator by putting too many lights on a unit. Most are rated at 1 amp, but 3 amps is common and larger values are obtainable. A bulb can pull ~1/4 amp.
If you want to save a trip to Orvac, you can buy ready made adjustable regulators through Allelectronics:
http://www.allelectronics.com/make-a-store/item/dcc-3/step-down-dc-regulator/1.html
Or make your own with a Goldmine 10 volt, 2 amp regulator chip:
http://www.goldmine-elec-products.com/prodinfo.asp?number=G20783
But be aware of the caveats using this method:
Because the track voltage can change polarity, the regulator must be preceeded by a bridge rectifier so that the regulator receives the same polarity every time. This is not necessary if you run your trains the same direction EVERY TIME…, but who does that? A couple caps are also used in the circuit and these other pieces will add a couple dollars to each regulator circuit that you build.
The voltage output (e.g., 10 volts) is about 2.5-3 volts lower than the voltage input. So for the 10 volts of output, you need to be running the trains at about 13+ volts.
If the voltage input is not 2.5-3 volts greater than the rated output, the lights will not continue to dim down to nothingness (as they do with simple track power), but will go dark. The upshot is that if your train is making its way around the pike at say 14 volts and the structures are fully lit, and you want to slow the train to 10 volts as you approach the station, the passengers will get a chilly reception when all the lights go out as the train pulls through. (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-embarassed.gif)
I use voltage regulators off my track power for a number of things, including my all important Bump A.S.S. crossing protection. But I use 5 or 6 volt regulators and these become active at ~8 volts. When my trains are running, they are running >8 volts in the area where I’m using that item (e.g., crossing protection), so this has never been an issue.
For the money spent on regulators, the dropping resistor is a low cost solution for bulbs.
Leds can be purchased that have low light levels and do draw a lot less current and most of the power wasted will end up on a (large) heat sink.
When you use a current regulator IC like the CL2, you don’t waste that power in heat, they run nice and cool… been using them for at least as long as Dick. Really good solution on higher voltage track power.
Greg
For leds and cost, a CL2 would be great on DCC with 6 leds in series and less wiring to boot.
Many good suggestions - thank you.
As to the current (pun) power system, I have variable track power – three rheostats for three 75’ sections of track with a ten amp Aristo Craft power supply that powers them. Rationale for the three controllers is varying grades in the track. Plus, there is a 10 amp MRC power pack running a 75’ back-'n-forth street car line.
Wendell
so now you need lights that work at pretty low track voltage… and work on varying voltage so resistors are out - they pretty much need a fixed voltage… get a cl2 and run two leds in parallel, each gets 10 ma and will light at about 7 or 8 volts on the track, maybe lower… and the brightness will be constant above that voltage
