So here I'm showing the beloved Tectronics 370B curve tracer.

It is a piece of test instrumentation that allow us to

obtain the characteristic curves for various devices.

So somewhere here in this socket, right there,

I have inserted a two-end 441 transistor, an NPN BJT transistor.

And I have set the controls to produce, in this case,

a set of output characteristic curves.

By changing the controls, I can generate a transfer characteristic curve.

And then I can save this data either as a picture or as numerical data.

And, what I want to do here in the following, is use the data

obtained in the curve tracer to determine the parameters of this transistor.

So if we have this transistor with unknown parameters,

we can use the curve tracer to make a measurements.

Then solve for those parameters and

then we know how this transistor will behave when operated in its active region.

So here I'm showing a set of measured output characteristic curves from

the curve tracer.

And what I want to do is use this data to determine the two transistor parameters,

the early voltage and beta naught, using the equations that we derived earlier.

Now remember the output characteristic curves.

Indicate the relationship between the collector current and

the collector to emitter voltage for the transistor.

So I want to pick two points on a single IB curve on the output characteristics.

And I'm going to choose this point here and

this point here, no, let's choose this point here.