Hello,
I ran a bias point simulation in PSPICE of the circuit. I am wondering what the prefix capital K is. Is that kilo? That seems too large of a current.

 

Hello,

I do not know PSPICE.
Lots of members over here use LTspice.
I also see that the base-emittor voltage is very high (1.215V).
Normaly I would expect 0.6 - 0.7 Volts.

Bertus

 

Hello,
I ran a bias point simulation in PSPICE of the circuit. I am wondering what the prefix capital K is. Is that kilo? That seems too large of a current.
View attachment 92734

Look at where all the current is going.

The problem (and you will have this with any simulator based on PSpice, which includes LT Spice) is that the simulator input files are case-insensitive. Hence your 1M base resistor is 1 mΩ, not 1 MΩ. The prefix for mega is meg (or MEG).

So how might you have spotted this?

Whenever you get wonky results, walk through things and see where the wonkiness is focused.

Consider the voltage across the base resistor is (20 V - 1.215 V) = 18.785 V. You have 18.79 kA flowing through it. So using those you get a base resistance of 1 mΩ.

 

Look at where all the current is going.

The problem (and you will have this with any simulator based on PSpice, which includes LT Spice) is that the simulator input files are case-insensitive. Hence your 1M base resistor is 1 mΩ, not 1 MΩ. The prefix for mega is meg (or MEG).

So how might you have spotted this?

Whenever you get wonky results, walk through things and see where the wonkiness is focused.

Consider the voltage across the base resistor is (20 V - 1.215 V) = 18.785 V. You have 18.79 kA flowing through it. So using those you get a base resistance of 1 mΩ.

Ah, that makes sense. I'll have to rerun the simulation in LTSPICE.

 

Why do you have to rerun it in LTSPICE? Just correct the error (which will be the same error in LTSPICE) and rerun it in PSPICE.

 

Why do you have to rerun it in LTSPICE? Just correct the error (which will be the same error in LTSPICE) and rerun it in PSPICE.

That's a good point. I'll remember to type 1000000 or 1meg. But they lock the lab, which has the only computers with the licenses for PSPICE, and I had to quickly run the simulation since the lab took the full time.

 

I'd recommend using 1meg as it is awfully easy to be off by one zero in 1000000 and not catch it.

 

You can always use scientific notation ...