High frequency capacitors

Thread Starter

TAKYMOUNIR

Joined Jun 23, 2008
352
What is the difference between the high frquency cap and other cap (i know from its name that it is better in hf) is this work like other cap block dc and pass ac or what is the difference and which caps is the best in hf
and what will happen if i use regular cap istead of using hf cap
thanks
 

takao21203

Joined Apr 28, 2012
3,702
What is the difference between the high frquency cap and other cap (i know from its name that it is better in hf) is this work like other cap block dc and pass ac or what is the difference and which caps is the best in hf
and what will happen if i use regular cap istead of using hf cap
thanks
Standard caps just don't work right with H.F.

Sometimes you will just experience some loss.
Sometimes the cap will get hot.
Sometimes the circuit may not work properly or not at all.
 

Ron H

Joined Apr 14, 2005
7,063
which kind of capacitors is good in high frequency and high voltage ,and high frequency and low voltage
thanks
I hate to say this, but Google "high frequency capacitors". Manufacturers want you to buy their parts, so they will tell you all about them.
 

takao21203

Joined Apr 28, 2012
3,702
That's really too much generic.

Sometimes regular caps also work, but you'd trade off efficiency. And you'd obtain more noise. There is really the case when this does not really matter.

Even a long cable is a capacitor already. If you apply high frequency, you'd experience capacitive resistance. The higher the frequency, the lower that resistance will be.
 

Ron H

Joined Apr 14, 2005
7,063
Even a long cable is a capacitor already. If you apply high frequency, you'd experience capacitive resistance. The higher the frequency, the lower that resistance will be.
How is this relevant to the OP's question? BTW, capacitors have reactance. Any resistance is usually undesirable, especially in high frequency applications.
 

takao21203

Joined Apr 28, 2012
3,702
How is this relevant to the OP's question? BTW, capacitors have reactance. Any resistance is usually undesirable, especially in high frequency applications.
Capacitors also can opposse currents due to their internal inductance.
So it can appear like their internal resistance is increased.

Relevant answer? What does OP mean with high voltage?

10V could be seen as very high.
Or 200V. Or 10 kV.
 

JMac3108

Joined Aug 16, 2010
348
A real capacitor has inductance in addition to capacitance. A large part of this is in the packaging of the cap. At a high enough frequency the cap will start becoming less capacitive and more inductive.

Smaller packages have less inductance, i.e a surface mount ceramic cap is better than a through hole ceramic cap. An 0402 surface mount is better than an 0603, etc...
 

Thread Starter

TAKYMOUNIR

Joined Jun 23, 2008
352
Capacitors also can opposse currents due to their internal inductance.
So it can appear like their internal resistance is increased.

Relevant answer? What does OP mean with high voltage?

10V could be seen as very high.
Or 200V. Or 10 kV.
high voltage mean kv like 5kv or 10kv or more
thanks
 
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