Resistor and Capacitor in Parallel

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I told you. It is difficult to explain using normal words. It's beyond the existence of language...
CAUTION: Don't make them parallel at any cost!!!.
It will raise a big question mark(?) against the laws of physics and electronics.
 
so the value of the resistance is still 100 Ohms in this case, and the value of the capacitor is still 270pF?
Putting them in parallel does not change their values?

The capacitor is there as a filter (as it would be without the resistor) and the resistor is there to protect the base of the transistor (as it would if the capacitor wasn't there)?

Basically the two components are not interacting with each other, but are performing their own separate functions?

I hope that made sense...
 
mark_3094 said:
Huh? .
Click to expand...

hi Mark,
Two images:

The cap increases the drive to the base at switch ON and the voltage stored in the cap, drives the base negative at switch OFF.

Improves the switching speed of the transistor at the pulse/edges

Look at the overshoot of the edges pos and neg when the cap is present.
 

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Last edited:
I see...
Thanks for the diagrams. What software do you use?

Why does the base need to be driven to negative? Is that so the on / off is 'cleaner'?
 
mark_3094 said:
I see...
Thanks for the diagrams. What software do you use?

Why does the base need to be driven to negative? Is that so the on / off is 'cleaner'?
Click to expand...

LTSpice.

By driving the base negative the 'carriers' in the base region are quickly removed so the transistor switches OFF faster,

Cleaner isnt the correct term, it increases the switching speed so the edges are faster.
 
mark_3094 said:
I see...
Thanks for the diagrams. What software do you use?

Why does the base need to be driven to negative? Is that so the on / off is 'cleaner'?
Click to expand...
otherwise the pulse would have appeared like the attachment-an exaggeration though.....
 

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