# Circuit breaker question



## briangcc (Oct 11, 2012)

Didn't see an electrical section so if this is in the wrong place, please feel free to move it.

A while ago, I won a CMI sound and power pack. I purchased a couple more as they are beefier than the MRC packs used on my dad's layout but they have a massive drawback - the power protection is abysmal. If I get a short, it blows the power pack. Fuses get expensive after a while so does anyone have a source for a 12v DC 1AMP (I'd settle for 2AMP if need be) circuit breaker?

Thanks!


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## waltr (Aug 15, 2011)

Correct forum.

Check with electronic supply houses.

Another possibility would try a 'Polyfuse' which is slow but self resetting.

Here are some:
Breakers, 1A:
http://www.digikey.com/scripts/dkse...0&newproducts=0&ptm=0&fid=0&quantity=0&PV66=4

Polyfuse 1A:
http://www.digikey.com/scripts/dkse...ts=0&ptm=0&fid=0&quantity=0&PV16=2&PV16=14762


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## Big Ed (Jun 16, 2009)

I am surprised John didn't say anything here.

I know he posted some places on another thread, I can't find them.


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## gunrunnerjohn (Nov 10, 2010)

I guess I question a short blowing the powerpack, how fast does that happen? A breaker is going to take some time to trip.

I'm confused, how expensive can a 1A powerpack be? Why is this superior to others if it dies with a short circuit?


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## rrgrassi (May 3, 2012)

You could also use automotive 1 amp blade or round fuses. The blade fuses are cheap protection for power packs. Also check into automotive breakers.


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## briangcc (Oct 11, 2012)

Looks like they're lighting circuit fodder at this point.

They're vastly superior power packs as they have the grunt to power the layout. They also have sound built into them, not that I've listened to it but its there. The severe drawback is what I mentioned - the power protection is abysmal. If I get a short, say from one of my Varney or Globe from jumping the track, the power pack gets instantly fried. Not sure on the amp rating but I don't think they are 1A, I think they are much higher as they are spec'd by the manufacturer to run G scale equipment.

That's where the MRC units shine as those power packs trip and then reset. That's what I'm trying to duplicate with the CMI units. Already been the fuse route and after a while those cheap fuses equal a new MRC power pack in cost. Track work isn't the issue here, just happens from time to time. 

Now before touting Command Control, understand it would be a very significant investment for me - around 400 locomotives to outfit alone - so its NOT an option. That and I deal with computers all day long, last thing I want to do is debug a decoder. It's not in my best interests.


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