MLCC capacitor, size matters ?

A

Anil Jangra

Guest
Hi,

I used 1uF/100V MLCC once and now when I ordered the same capacitor again the specifications says its same but the size is smaller, about half of previous one. I want to know f the physical size matter and how ?
 
Anil Jangra wrote:

Hi,

I used 1uF/100V MLCC once and now when I ordered the same capacitor again the specifications says its same but the size is smaller, about half of previous one. I want to know f the physical size matter and how ?
Big things come in small packages..

Jamie
 
On Mon, 16 May 2011, Anil Jangra wrote:

Hi,

I used 1uF/100V MLCC once and now when I ordered the same capacitor again the
specifications says its same but the size is smaller, about half
of previous one. I want to know f the physical size matter and how ?

I have a 10,000uF 16v capacitor "computer grade" that I bought at a
fleamarket about 1973. It's as big as a Coke can. It was still
relatively difficult to get that high capacitance capacitors at that time,
and I had to live with a voltage rating that wasn't as high as I would
have liked.

Now, you can get the same capacity and voltage in a capacitor about the
size of a thumb. And that's not even a recent thing.

In the old days, one might expect to find 40uF as about the largest
capacity one could find in a 150v or so capacitor. Few applications
needed something bigger. About 20 years ago, I had ripple on my Tektronix
scope, and it clearly was a filter capacitor. I worried when I looked at
the schematic, they were higher capacitance capacitors than I remember
being common at higher voltages. But I visit the local surplus store, and
found what I needed.

I still have oil filled 1uF capacitors of higher voltage that I got in a
box of junk about 1972. They are big.

Forty years ago, the hobby electronic magazines would run cartoons, and
more than once they'd make fun of the notion of a really large capacitor.
Nobody talked in terms of 1Farad capacitors, nobody had a need and nobody
made them. But extrapolating from some common value electrolytic, one did
assume they'd be pretty big. Yet when they came into existence, they
weren't, they were downright tiny.

In the days of vacuum tubes, there wasn't much need for large value
capacitors, since the tubes were high voltage, high impedance devices. It
wasonly when transistors came along that there was a large need for higher
value electrolytics. A tube receiver would have a handful, in the power
supply and then to bypass the cahtode audio amplifier stage(s). Even
early transistor radios had loads of electrolytics, since transistors were
low voltage/low impedance devices, there was a sudden need for higher
capacity capacitors.

That drove a lot of work on making better electrolytics, higher capacity
and then make them smaller (since the number required by a circuit could
use up a lot of space).

And it worked. Higher capacity capacitors available in pretty small
packages, compared to the old days when "high capacitance" was
relative, and they'd come in a large package.

Michael
 
Anil Jangra wrote:

I used 1uF/100V MLCC once and now when I ordered the same capacitor again the specifications says its same but the size is smaller, about half of previous one. I want to know f the physical size matter and how ?
Please limit your line length to 70 characters or so.

I observed stronger piezoelectric effect in the current BaTiO3 MLCCs
than in larger ones assembled more than ten years ago. This can cause
audible noise if they are subject to AF AC voltage.

Oliver
--
Oliver Betz, Munich
despammed.com is broken, use Reply-To:
 

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