Bridge rectifier and polarity 'oops'

I plugged into LTSpice the schematic for a bridge rectifier to test if it could negotiate the change in DC polarity - which it did.

How much wear will the bridge endure before failing?

Along the train tracks, as it is now it is still in development, I have segments that have reduced voltage and different polarity depending on the function of the segment.

At this stage, I am only testing over a 3m section of track.

Reply to
Wayne.
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That depends on a lot of factors, all of which you have not told us. Generally, in a properly designed system with suitable margins, they won't (or shouldn't) fail.

Your post really doesn't make any sense. What are you trying to do here?

Dave.

Reply to
David L. Jones

"Wayne Kerr"

** Will miracles never cease ......
** We might well ask - how much can a Koala bear ????

Toooot, toooot ...............

....... phil

Reply to
Phil Allison

If you are talking about a small model train set........

You need to know how much current the train(s) draw - I'd guess a small toy train would draw < 2A, probably 300mA+ when running. Try something like a W04 bridge. Be aware that a bridge will lose arount 2 x 0.7V. Your trains may not run at full speed with the bridge in circuit.

Reply to
Cosmic Ray

Well, if the change in polarity is happening across the AC or ~ terminals, and the voltage current ratings are followed, and the frequency isnt high (you need a fast recovery type if so) the thing shouldnt wear out for a long long time - possibly decades even.

Reply to
kreed

That's modern education for you ! We're producing a generation of clowns, idiots and know-nothings. And many are functionally quite illiterate and innumerate too.

Graham

Reply to
Eeyore

MORON ! 0.7V is a small signal current Vf for typical silcon diodes.

Power bridges are more in the region of 1V per diode at rated If.

Sigh !

Graham

Reply to
Eeyore

Uh ?

How did you understand his 'question' ?

Graham

Reply to
Eeyore

the bridge should be rated for the stall current, when the motor is running at full speed there will be less drop.

Bye. Jasen

Reply to
Jasen Betts

Had a graduate recently apply for a job who could not calculate a circuit with 1 zener, 1 battery and 1 resistor!

Reply to
geoffjunkster

I didnt really, just made guesses :)

Reply to
kreed

LOL !

Graham

Reply to
Eeyore

I read through an article using a 6v dolphin battery and an LED. To overcome the polarity in the dark, the author used a bridge rectifier.

What I am wondering, can this be relied upon when the train tracks change polarity through a turn-out loop?

Oh, and no I am not a student. Just someone who want to do something fancy with a train set that I am resurrecting after 20 years of sitting idol.

Reply to
Wayne.

Absolutely,

If the voltage on the tracks changes that may cause brightness changes in the LED, that depends on how your loco is controlled.

Bye. Jasen

Reply to
Jasen Betts

Sadly doesn't surprise me.

I was helping out my nephew with an op-amp problem a little while back. He finally got the gain equation right with some prompting but then told me he needed a calculator. I said "use the one on your PC" but he said he needed an 'expression evaluator calculator' ! For something like A = B + ((C+D)/(E-F)) !

I got the answer accurate to 1 decimal place in my head FFS.

Now go to Asia and see if they can answer it !

Graham

Reply to
Eeyore

And you don't need effing LTSpice to tell you that !

Graham

Reply to
Eeyore

LOL !

Graham

Reply to
Eeyore

Guffaw ! What the heck DO they actually do for those 3 years ?

Graham

Reply to
Eeyore

If you want to do something fancy then go with DCC:

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Just buy the modules and controllers you need.

Dave.

Reply to
David L. Jones

If my layout was bigger, then DCC is definitely the path I would take.

There was an article in RailBrick e-zine discussing DCC and Lego trains, plus there is several sites dedicated to or have information about DCC and similar controls.

Reply to
Wayne.

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