Jfet Characteristics JFET CHARACTERISTICS ENR 213 LAB # 5 FEBRUARY 15, 2001 Aaron Smith PURPOSE: The purpose of this lab is to design a voltage-divider bias BJT transistor configuration given specific circuit responses. The circuit specifications are as follows: VCC = 15V, IC = 5mA, VCE = 7.5V, and VE = .1VCC = 1.5V. PROCEDURE: The same procedure will be done twice, first with a 2N3904 transistor than with a 2N4401 transistor. Determine the value of RC and RE for the given specifications. Define the relationship between R1 and R2 assuming that RE * 10R2 is satisfied.
Calculate R2 and pick the closest commercial value for your circuit. Then, plug the value of R2 into your derived relationship and solve for R1. Next, construct the circuit. Measure all voltages and calculate the currents. Then determine the value of .
Compare your predicted values to the measured values. CONCLUSION: We defined the relationship between R1 and R2 to be 2.2R1 = 12.8R2. By doing so, we were able to find values for R1 and R2 which would yield the desired variables. When comparing our results for each transistor, we saw that an increasing value doesnt affect the voltages and currents much. Our values were 152 for the 2N3904 transistor and 176 for the 2N4401 transistor. For instance, our value of IC was 4.8mA for the 2N3904 transistor and 4.93mA for the 2N4401 transistor. We calculated the stability factor for our circuit to be 1.13.
This further proved our predictions that does not have much impact on this type of configuration. Engineering.