Hey guys, back in the day it was common to use auto bulbs in the wiring to use as a circuit breaker if there a short.
Do any of you remember how this was done?
Hi there,
You use a 12V Brake lamp or similar in series with the load, that is your track. Until your train shorts the track or you put a heavy drawing motor on, it will not show or at worst be a dim light until it is loaded up.
I use a few 10 Watt resistors in series with the load to achieve the same degree of protection for my throttle circuits, I just do not get the indicators that you would when the light glows...
Hope this helps
Regards
Trevor www.xdford.digitalzones.com FYI
Joe Fugate has posted a lot of information on this technique. This is part of a thread he authored on wiring in general.
http://cs.trains.com/forums/5/467624/ShowPost.aspx#467624
You might want to Google around for Joe's information on the web. Lots of good stuff there about many aspects of the hobby.
Oh, and if you get a minute, could you delete the duplicate post? Thanks.
It takes an iron man to play with a toy iron horse.
1156 Bulbs for short protection - detailed current study
Here is a link to Joe's clinic on this subject.
If you arfe interested in links to some of Joe's other information and endeavors, such as his excellent scenery clinic, just click the banner in my signature to find links to that and other resources at the bottom of my main page.
xdford wrote:Hi there,You use a 12V Brake lamp or similar in series with the load, that is your track. Until your train shorts the track or you put a heavy drawing motor on, it will not show or at worst be a dim light until it is loaded up. I use a few 10 Watt resistors in series with the load to achieve the same degree of protection for my throttle circuits, I just do not get the indicators that you would when the light glows... Hope this helps Regards Trevor www.xdford.digitalzones.com FYI
That's how you do it but avoid the resistors. You need a temperature variable resistance, not a fixed resistance or you will simply be wasting power by making heat. (Yes it will limit current).Tail light bulbs have very low resistance when cold. As the current rises the filiament heats up, lights up and rises in resistance, limiting you to two amps but dropping essentially no voltage at all at normal currents.
Karl
The mind is like a parachute. It works better when it's open. www.stremy.net
Hi Karl,
I have been using the resistors for years but you have persuaded me and I'll swap to lamps soon! I have had a problem with running more than 3 locos together... not that that happens very often given my layout. Thinking about it, I can see other problems arising too with the resistors such as getting warm and possibly causing some slightly erratic operation being the inductive load with a resistor in series!
In fact I can hardly wait to try it,
Thanks from down under
Trevor www.xdford.digitalzones.com FYI including links to the MRE hints and Tips page and making a range of items.
xdford wrote:Thanks from down under
You're welcome. I have to make that EE degree payoff somewhere
Catt wrote: Hey guys, back in the day it was common to use auto bulbs in the wiring to use as a circuit breaker if there a short.Do any of you remember how this was done?
Do youself a favor. If you are really concerned about short circuit protection, get youself one of those breakers that Tony's Train Exchange sells. The lightbulb method does not provide short circuit protection....it is only a current limiter.
I'm speaking from experience. I tried the bulb method and it did limit current okay, but it caused some other issues and lead to some other concerns. With all due respect to those folks who are proponents of this method, it may have been okay at the time it was first developed. But that time has passed and the "real" circuit breaker does a better job.
As they say, that's my farthings worth.