voltage derating means??

[mone]

can any one explain abt voltage derating with some examples or application?I need both pros and cons under this topic?

 

[Ubergeek63]

voltage derating is used to extend the life of components. in the military it is very common but in consumer products you generally only hear about it in reference to electrolytic capacitors.

basically less stress equals longer service life.

Dan

 

[mone]

can you please send me a circuit with the example of where this voltage derating is used and how it is used? because in one of my design,tantalum capacitor is keep on getting burst .I couldnt resolve the isse??

 

[Reloadron]

can any one explain abt voltage derating with some examples or application?I need both pros and cons under this topic?

Sounds like a homework assignment?

I would start by reading **broken link removed** You will also find a few cons to derating when doing design work under caveats.

After reading a little if you have questions then ask.

Saw your second post:

can you please send me a circuit with the example of where this voltage derating is used and how it is used? because in one of my design,tantalum capacitor is keep on getting burst .I couldnt resolve the isse??

You need to specify where the capacitor is used as in the environment. What temperatures? What voltage? If I run a cap rated at 16 volts in a 15 volt circuit I can pretty much figure it will have a bad life. Since it birst you are sure there is not a polarity issue? Have you looked at the manufacturers data sheet on the cap(s) you are using?

Ron

 

[Ubergeek63]

can you please send me a circuit with the example of where this voltage derating is used and how it is used? because in one of my design,tantalum capacitor is keep on getting burst .I couldnt resolve the isse??

you might be over heating it when soldering as well... tants do not like high temps. we had some that would not even survive reflow here... turns out the voltage rating was compromised by soldering temperatures. we had to change to ceramics since it costs more to hand solder than it does to buy a better part.

 

[mone]

K ron thanks soo much...but let me tell you some thing,wat i'm using is a simple power circuit which is having enough protective components in design but inspite of this , my tantalum capacitor is getting burst.Inouts
Vin=24v
Capacitor burning is tantalum,kemet manufacturer 10uf ,50v
Ic used for circuit is LM2596-ADJ,national semiconductors
i'll post the schematic plz check in

 

[Nigel Goodwin]

can you please send me a circuit with the example of where this voltage derating is used and how it is used? because in one of my design,tantalum capacitor is keep on getting burst .I couldnt resolve the isse??

I would suggest not using tantalum capacitors, over the years they have proven VERY unreliable, and rarely seen in domestic equipment since the late 70's or early 80's?. Still they were good for repairs , spot a tantalum, change it - usually cured the problem

But tantalums are VERY, VERY suscepible to over voltage, they go S/C at the slightest suggestion of overvoltage.

 

[jenifer85]

Yes don't use tantalum capacitors, it's old stuff.

 

[mone]

i wanted to know the basic reason why it got burst...can you suspect some reason so that i can manually feed the cause and check where to overcome??

 

[Nigel Goodwin]

i wanted to know the basic reason why it got burst...can you suspect some reason so that i can manually feed the cause and check where to overcome??

Post the circuit, over voltage is the usual reason (apart from tantalum been crap)

 

[crutschow]

Yes don't use tantalum capacitors, it's old stuff.

Tantalums are still use widely in high rel military and space electronics with very few failures, as long as they are properly de-rated (at least 50% in voltage). You have to use an electrolytic capacitor (tantalum or aluminum) if you want large capacitance in a small space.

 

[crutschow]

Have you monitored the voltage across the capacitor with an oscilloscope under all conditions of operation, including startup?

 

[ronv]

I can't open your file but since it's a regulator circuit my guess would be that the problem is with ripple current not voltage. Change to a low esr alluminum electrolytic. Usually they will spec. ripple current. Staying under it is a good example of derating.

 

[ronv]

Derating

Sorry, the tanalum should have low esr so that's probably not it. Is it a pc board or breadboard? In the right polarity? Get it to hot during solder? Any chance of reverse polarity when the supply is off? (another supply still on).

 

[mone]

Did yu see the schematic which i've posted ??

 

[mone]

yes and this case happens very rare.As we have power supply circuit in almost all the pCB's ,this capacitor is failing to work in almost all the PCB's one by one.??

 

[Reloadron]

You have eliminated the possibility of a bad lot from a manufacturer?

Ron