Behavior of Circuit

[kingofjong]

Hi

I was wondering if any one could explain the behavior of the transistor circuit pasted bellow. I am giving the collector a pulse that is 0.6 seconds in length and the emitter produces a pulse that is 0.3 seconds in length. I was wondering why the pulse gets shorter.

 

[alec_t]

Because you are giving a 0.3 sec pulse to the base.

 

[crutschow]

That's an emitter-follower circuit.
Why are you pulsing the base and collector with different pulses?
What do you expect the circuit to do?
Normally you apply a constant DC voltage to collector and, when you pulse the base, you will get the same the pulse (minus the base-emitter voltage drop) at the emitter output.

 

[kingofjong]

Hi

I was hoping the collector output would show up and start at 1.2 seconds. Usually in NPN transistors current flows from collector to emitter?

Thanks

 

[crutschow]

I was hoping the collector output would show up and start at 1.2 seconds.

What do you expect the "collector output" that "shows up" to be?

 

[Nigel Goodwin]

Usually in NPN transistors current flows from collector to emitter?

It flows where ever you design it to do so, and depends on what you consider current flow?.

 

[ronsimpson]

It flows where ever you design it to do so

It flows by the laws of Physics. Your design, is what you want it to do. When your design does not work the way you want, then you probably are butting heads against a law you don't understand.

what you consider current flow?

There is a continual fight over if current flows from + to - or from - to +. (electrons are negative)

I was hoping the collector output would show up

Because the Collector is connected to V2 the collector voltage will look just like V2 voltage.

 

[gophert]

It flows by the laws of Physics. Your design, is what you want it to do. When your design does not work the way you want, then you probably are butting heads against a law you don't understand.

There is a continual fight over if current flows from + to - or from - to +. (electrons are negative)

Because the Collector is connected to V2 the collector voltage will look just like V2 voltage.

Electrons are negative, true. If you want to talk about moving electrons, you should be calling it "electron flow". There is no doubt in my mind that Positive current flow is from + to - and anyone who wants to argue over it is a pedantic idiot and not worth my time. (I realize you are just clarifying - and clearly not an idiot - but have you seen the "textbook" on that other Electronics website? What a bunch of tools over there).

 

[ronsimpson]

bunch of tools over there

Tools are every where.
Most people think I am a .......

The current flow question is much like the bank and I. I think in $ and the bank thinks in debt. So debt flows from one person to another very much like money flows but in the reverse direction.

 

[gophert]

Tools are every where.
Most people think I am a .......

The current flow question is much like the bank and I. I think in $ and the bank thinks in debt. So debt flows from one person to another very much like money flows but in the reverse direction.

Too bad you can't just switch the leads of the meter on the bank account values to turn those frowns upside down.