(1) The maximum motor current occurs when the motor wheel is locked. By selecting resistor values R _b1 and R _b2 in the motor driver circuit seen in Figure, it is possible to limit this maximum current. Using the equivalent circuit models for PNP and NPN transistors, solve for R _b1 = R _b2 =R _b such that the maximum motor current is 1A. Use the value found in Experiment for R _Motor . Assume the following parameters:

(a) V _BEI = V _EB4 = 0.8V

(b) ? ₁ = ? ₄ =200

Figure-Motor driver circuit when the wheel is locked and the maximum voltage is applied by grounding one control signal (B2) and supplying 10V to the other control signal (B1)

(2) What actual resistance value will be used in your circuit? What maximum current does using this resistor result in?

10VDC B1 Rb1 GND Q1 Q3 Rmotor Q2 Q4 Rb2 B2