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Transistor dc gain ?

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The term hFE is DC current gain at high current or low current.
The term hfe is AC current gain at high current or low current.
 
The term hFE is DC current gain at high current or low current.
The term hfe is AC current gain at high current or low current.
That's correct. hFE does not just refer to high current (as I stated) but any DC current (sometimes called large signal).
 
DC is not a signal. AC is a signal.

hi agu,
How can DC not be a signal.?
After all DC stands for Direct Current and AC stands for Alternating current, the only difference I know of between the two ie: DC and AC
is that direct current does not change its direction of flow with time whereas alternating current does change direction of flow with respect to time...

So from my understanding, both DC and AC are both in effect signals.?

I guess that your interpretation of the DC and AC states is based on its usage in some semiconductor datasheets.

I would agree with Carl, there is some confusion of the definitions of hFE , hfe and DC [saturation states].
It seems to depend upon which datasheet or data source you take as the reference.
 
All transistor datasheets that I have seen call hFE "DC Current Gain".

All transistor datasheets that I have seen show hfe at 1kHz (small signal current gain). Fairchild's datasheets show the hfe dropping as the signal frequency approaches the gain-bandwidth product.
 
Hi Eric,

I think he did answer your comment.

All transistor datasheets that I have seen call hFE "DC Current Gain".

All transistor datasheets that I have seen show hfe at 1kHz (small signal current gain).
 
Hi Eric,

I think he did answer your comment.

All transistor datasheets that I have seen call hFE "DC Current Gain".

All transistor datasheets that I have seen show hfe at 1kHz (small signal current gain).

hi,
Sorry to disagree, but he did not reply to my question regarding his post..

. agu>...DC is not a signal. AC is a signal.

Which is nonsense and misleading to wannabees

Eric
 
I have never heard a DC audio signal.
I have never seen a DC video signal.
 
I have never heard a DC audio signal.
I have never seen a DC video signal.

You see the result of a varying DC signal every time you watch your TV.

000esp01.gif

Also you hear the varying DC demodulated signal when listening to your radio.
 
An AC signal alternates its polarity. A bouncing DC level does not alternate and is not an AC signal.
 
An AC signal alternates its polarity. A bouncing DC level does not alternate and is not an AC signal.

No one said that varying DC is an AC signal, so stop playing around with the words and statements that I have posted.

You have made a mistake, which we all do from time to time, so please be good enough to admit it and lets move on.!
 
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