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- Homework Statement
- An inductor is energized as in the circuit shown in fig. The circuit has L =100 mH, R= 20 ohm, VCC= 90 V, t1= 4 ms, and T= 40 ms. Assuming the transistor and diode are ideal, determine (a) the peak energy stored in the inductor, (b) the energy absorbed by the resistor in each switching period, and (c) the average power supplied by the source. (d) If the resistor is changed to 40 ohm, what is the average power supplied by the source?

- Relevant Equations
- P = V*I Watts; V_L = Ldi/dt

The figure is as shown below

a. From 0< t < t1 => 0 <t<4ms, the transistor is "ON"

The circuit will become like this

The current ##i_s = i_L##. To know the magnitude of the current ##i_L## do i need to know the impedance of the inductance or since it is DC voltage the impedance is not applicable? The energy stored will then be ##E=\frac{LI^2} 2##.

The circuit during t1<t < T => 4<t<40ms will be

There is a voltage ##V_L## developed across the inductor because of the previous cycle and hence it forward biases the diode. There is no current flow through the source as the transistor is off. The inductor discharges through the resistor. My problem is how to use the equations and find the voltages and currents. Please help.

a. From 0< t < t1 => 0 <t<4ms, the transistor is "ON"

The circuit will become like this

The current ##i_s = i_L##. To know the magnitude of the current ##i_L## do i need to know the impedance of the inductance or since it is DC voltage the impedance is not applicable? The energy stored will then be ##E=\frac{LI^2} 2##.

The circuit during t1<t < T => 4<t<40ms will be

There is a voltage ##V_L## developed across the inductor because of the previous cycle and hence it forward biases the diode. There is no current flow through the source as the transistor is off. The inductor discharges through the resistor. My problem is how to use the equations and find the voltages and currents. Please help.