4.71 A full-wave rectifier circuit with a 1-kΩ operates from a 120-V (rms) 60-Hz household supply through a 6-to-1 transformer having a center-tapped secondary winding. It uses two silicon diodes that can be modeled to have a 0.7-V drop for all currents. What is the peak voltage of the rectified output? For what fraction of a cycle does each diode conduct? What is the average output voltage? What is the average current in the load?

Respuesta :

Answer:

[tex]V_{p (load)} = 28,3 V - 0,7 V = 27,6 V[/tex]

[tex]V_{p (load)} = 27,6 V\\V_{avg} = 17,57 V[/tex]

The upper diode conduces in the odd half cycles. The lower diode conduces in the even half cycles.

[tex]I_{avg} = \frac{V_{avg}}{R_{load}} = \frac{17,57 V}{1000 Ω} = 17,57 mA[/tex]

Explanation:

The peak voltage after the 6 to 1 step down is [tex]V_{p} = \frac{120}{6} \sqrt{2} =  28,3V[/tex]. Then, the peak voltage of the rectified output is [tex]V_{p} - [tex]V_{avg} = \frac{2V_{p (load)} }{\pi}  = \frac{55,2 V}{\pi } = 17,6 V[/tex]V_{d}[/tex] and according to the statement, the diodes can be modeled to be [tex]V_{d} = 0,7 V[/tex]. Then, the peak voltage in the load is [tex]V_{p (load)} = 28,3 V - 0,7 V = 27,6 V[/tex].

The upper diode conduces in the odd half cycles. The lower diode conduces in the even half cycles.

The average output voltage is calculated as:

[tex]V_{p (load)} = 27,6 V\\V_{avg} = 17,57 V[/tex]

The average current in the load is calculated as:

[tex]I_{avg} = \frac{V_{avg}}{R_{load}} = \frac{17,57 V}{1000 Ω} = 17,57 mA[/tex]