Common emitter configuration opposite

Thread Starter

abdulbadii

Joined Aug 30, 2017
85
How is the simplest circuit of common emitter configuration inverse/opposite that has a switching to open on high base current and to close/shorted on no/low base current ?
 

ElectricSpidey

Joined Dec 2, 2017
2,758
I wish I was on my other machine I could make a schematic.

But I think what you want is to use one transistor to shunt the base current from a second one.

I'm sure someone will provide a schematic.
 

MrAl

Joined Jun 17, 2014
11,389
How is the simplest circuit of common emitter configuration inverse/opposite that has a switching to open on high base current and to close/shorted on no/low base current ?
Wouldnt that be a PNP circuit? When you make the input high the output turns off, when you make the input low the output turns on. That's if i understand what you really want to get out of this. You may want to add some information to your first post to better describe it.
 

MrAl

Joined Jun 17, 2014
11,389
Depends on how the OP means "high and Low" current.
Yes, and after all they are asking about a current, if that is what they really mean that is. If they are really asking about a current i believe your answer could be better because any transistor that takes a current input will produce a current output and to reverse that action you need two stages as a minimum i think, unless of course you can provide dual polarity currents where one cancels the other out, thus turning the single transistor off.
 

MrAl

Joined Jun 17, 2014
11,389
Hello again,

This is what i was trying to show.
I borrowed MrChips' drawing (i hope that's ok with you MrChips) the first one near the top, to show the output waverform relationships.

This is just three ways it may be done. The last one near the bottom operates with pure electrical currents as the original question suggested. The bias current is shown as fixed but it doesnt really have to be as long as we know the min and the max.
 

Attachments

Top