In order to draw the load line of transistor, we have to find out the saturation current (where the voltage is minimum or zero) and voltage of collector-base when collector current is zero.

In order to calculate maximum saturation current, we have to forward biased the base-emitter, and reverse biased the base -collector and then get the voltage of collector-emitter to be zero(V of collector minus voltage of emitter equals to zero), right??

Thank you

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 I think 'we have to forward biased the base-emitter, and reverse biased the base' instead of both forward because when we forward both we can't get a constant curve at saturation region, correct?
 the base-emitter junction is always forward biased as long as the transistor is not in full "cut-off" (where the collector current is zero). so, from the POV of the load line, the base-emitter is forward biased, usually by about 0.6 volts.

 Quote by rbj the base-emitter junction is always forward biased as long as the transistor is not in full "cut-off" (where the collector current is zero). so, from the POV of the load line, the base-emitter is forward biased, usually by about 0.6 volts.

what is POV?
The base-emitter is usually 0.7V.
How to draw a load line?

Mentor
 Quote by Outrageous what is POV? The base-emitter is usually 0.7V. How to draw a load line?
POV = "point of view"

 Mentor Maybe this will help: http://www.youtube.com/watch?v=KzfrxjCJ8Gg .
 First of all there is not one load line for a transistor. There are many and they depend upon the circuit configuration. Having said that, for a resistive load the load line is a straight line so you only need to find two points and join them to be able to draw one. To draw a load line for R ohms on the collector current (y axis) v collector voltage (x axis) curves: 1)Locate the point of the voltage axis corresponding to the supply voltage. 2)Locate the point on the current axis which the supply voltage would drive through R ohms. 3) Join these two points to form the load line for R ohms. go well

 Quote by berkeman Maybe this will help: http://www.youtube.com/watch?v=KzfrxjCJ8Gg
 Quote by Studiot First of all there is not one load line for a transistor. There are many and they depend upon the circuit configuration. Having said that, for a resistive load the load line is a straight line so you only need to find two points and join them to be able to draw one. To draw a load line for R ohms on the collector current (y axis) v collector voltage (x axis) curves: 1)Locate the point of the voltage axis corresponding to the supply voltage. 2)Locate the point on the current axis which the supply voltage would drive through R ohms. 3) Join these two points to form the load line for R ohms.

 Quote by Outrageous The base-emitter is usually 0.7V.
okay. whatever. from long ago, when i was a graduate teaching assistant (and i was teaching a lab), it was most often 0.6v for silicon.

 How to draw a load line?
well, your transistor curve is that of a function $I_c$ as a function of $V_{ce}$ for various $I_b$. so given an $I_b$, you still don't know what $I_c$ is without also knowing $V_{ce}$. the load line is another equation that relates $I_c$ and $V_{ce}$. and that equation comes from the rest of the circuit (assuming no $R_e$:

$$V_{cc} = V_{ce} + I_c R_c$$

or

$$I_c = \frac{1}{R_c} ( V_{cc} - V_{ce} )$$

plotting that equation on top of the transistor curves is your load line.

 Quote by rbj okay. whatever. from long ago, when i was a graduate teaching assistant (and i was teaching a lab), it was most often 0.6v for silicon. well, your transistor curve is that of a function $I_c$ as a function of $V_{ce}$ for various $I_b$. so given an $I_b$, you still don't know what $I_c$ is without also knowing $V_{ce}$. the load line is another equation that relates $I_c$ and $V_{ce}$. and that equation comes from the rest of the circuit (assuming no $R_e$: $$V_{cc} = V_{ce} + I_c R_c$$ or $$I_c = \frac{1}{R_c} ( V_{cc} - V_{ce} )$$ plotting that equation on top of the transistor curves is your load line.
Understand.
when there is $R_e$ ,we can use the equation in this (transistor load line)