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Computer Grade Cap or Inverter Grade Cap???

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Hi all expert,

Anyone can explain what is Computer Grade Cap and Inverter Grade Cap? (Other than used in computer and inverter. )

I know the computer grade cap is more expensive. Some of them are in high voltge (e.g. 450V DC), it doesn't look like used in computer......

I think it may be just 2 grade of cap (obviously higher than ordinary cap).

But what is the specification/range for a cap can be called as computer grade/inverter grade?

Computer Grade is higher or Inverter Grade is higher?

Thank you in advance.

Tuna Fish
:)
 
Computer grade caps used to be used in computers, the big mainframes of the 50s to 80s. This was before rock-solid tons-of-amps transistors made switching power supplies possible, but the circuits still required the same stable power supply. You can imagine how annoying a 5V at 250A power supply was... :D

Inverter grade caps are made for inverters, obviously, which demand high peak currents. Consider a 10kW inverter running a squarewave through its transformer, that's a good bit of power being switched eh? Something needs to supply, snub or filter that appetite.

Tim
 
When you take a look inside a regular inverter you will see Long Life capacitors for 105C.
A CG can handle larger surge values than a LL, 25 % above max is not uncommon. Which explains the huge size of CG's.

imo, the preferred audio electrolytic capacitor is a CG, 105C models if possible, because of the higher surge.
Both are LL versions.
I have been using Siemens/Sepcos Long Life, Sikorels, Roederstein, SifSafco, Mallory CGS.
Sikorels are the absolute best ; LL, +105C, extrem low esr and esl, but 3 times more expensive than regular good quality caps.
The Siemens Sikorel B41550/41570 were intended for very fast switching supplies.
For gain stage powersupplies i used the Sikorel inverter type cap, for an output stage that would mean serious money, there i use CG's
 
I am just cleaning an inverter, here is a picture of the caps.

Computer Grades are still used for big main frames, that is where i try to buy them from.
An Aluminium electrolytic is an alloy foil with an electrolytic layer on it, the foil is rolled up and and an insulating cap is placed around it.
Computer and inverter grades have a much thicker electrolyte layer, the thicker layer enhances the long term behavior of the caps, and more.
That is why both CG and LL inverter capacitors are much bigger, a CG up to 20 % more than a LL.
 

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TunaFish said:
What does the 40/105/56 and 40/85/56 indicated in capacitor means?

40/105/56 means the capacitor has been tested between -40 C and +105 C for 56 days.
Same with the 40/85/56.
The ISO/IEC have standard procedures, of which the 56 days is one, that enables someone to compare components.
The main parameters that influence capacitor performance are temperature and humidity.
A standard IEC procedure is placing capacitors in a surrounding with prescribed humidity percentage for 56 days at different temperature.
 
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