[tkruger]

I have an Athern Budd car with the band drive. It is not lit. I want to light it. I have 6v grain of wheat bulbs. Can I use these? Is there a way to wire them so that they never receive more than 6 volts, I.E. when the loco receives 1-5 the bulbs get 1-5 volts, when the loco gets 6 - 12 volts the bulb is limited to 6 volts. I normally run my trains at 30 - 40% power unless I have to give them 50 - 65% to climb a grade.

 

[T-Man]

Use them in pairs in series-12 volts. Though the power they actually receive is more likely 10 +. If that isn't bright enough use one bulb with a resistor.
6v /amp of bulb = ohms. The answer is around 500 ohms. i'll get back on this.
A 1.5 v may be better.

Trolley light Here I used a 12 v bulb. with .06amps.

Micro bulbs use .025 amps. in 1.5, 6, amd 12. A larger 12 uses .06 amps. This information is found on the packaging.
So 12v power -6 folts bulb =6v/.025amps= 240 ohms
Use two 120 ohm resistors. If you have 11v output you can go with one 220 ohm or play it safe all away around and go with a 330 ohm.

 

[tankist]

how about building tiny circuit based on 7805?
T-man, will it not work for some reason? i'm mostly down converting so not sure how it reacts to low input voltage..

 

[T-Man]

I use the 7805 for electronic flashers. Rather expensive for just lighting when a resistor will do. Make sure you have the correct connections at the 7805.
You will still need resistors to adjust to 5 v. The 6 v may work without one.
Check the package because the electric diagram is not wyswyg.

The diagram is right. Is it working for you?

 

[tankist]

i was thinking constant brightness lighting across the speed range (not sure bout the lower speeds thoguh). but perhaps you are right about the cost. i never factor it in as i have a bunch of everything laying around already ...

 

[T-Man]

Yes constant brightness is really the next step after just lighting. It depends what you want. At that stage it is trial and error to see if it is what you want. In Lionel the lower volatges are around 5 or 6 anyway. but the HO may be more efficient. I started into LED lighting but cost wise the normal micro's are better. So that is what I reccomend for lighting. I find other uses for the LEDs.