I am studying triode plate saturation and I am stuck on this question :

Plate saturation is the condition when :

(1) plate power dissipation is maximum recommended for the tube type

(2) secondary emission from the plate equals cathode current reaching the plate

(3) plate current does not further increase when the grid is made less negative
(4) maximum plate voltage is used


I think it might be 1 or 2.

In a vacuum tube, the space-charge-limited current, such that further increase in filament temperature produces no specific increase in anode current. In a vacuum tube, the temperature-limited current, such that a further increase in anode-cathode potential difference produces only a relatively small increase in current.

Maybe I am not seeing something again. thanks for any helpful hints.

 

I would have thought the plate was saturated when increasing the grid drive does not further affect the plate current. That would be the equivalent of signal clipping.

 

I'm with beenthere. Saturation has always been when the increase in drive signal does not effect a further increase in plate current ... your answer number 3.

 

From Ye auld NEETS module 6:

Remember that every cathode is able to emit just so many electrons. When that maximum number is being emitted, the tube is said to be at SATURATION or PLATE SATURATION. Saturation is reached in a triode when the voltages on the grid and plate combine to draw all the electrons from the space charge

Man are my NEETS modules dusty!

 

Update your dusty neets modules from the pdf's at davidson college.

Of course the other option is the 1998 CD version.

I'll have to check with nko and see if the pdf's at their site are more current than the pdfs at davidson college.

 

Thanks for the tip, Joe! http://www.phy.davidson.edu/instrum...ctronic Emission Tubes and Power Supplies.pdf
Bottom of page 1-15

Looks like the US government is still finding new ways to use more words to say the same old thing!

 

They always do ... and nko has updates ranging from 1998 up ... for the NEETS pdf's.

 

I would have thought the plate was saturated when increasing the grid drive does not further affect the plate current. That would be the equivalent of signal clipping.

oh ok. Now that I see the answer I understand it better thank you.

That would be if the grid is goes from -4 to -2. there would be increasing the grid but not increasing the plate current.