Question

With the circuit in the figure below we obtained the waveforms that can be visualized in the graph (Vsec peak: 17V / 60Hz, C = 653 uF, R = 60Ω, RL = 60Ω, Vz = 5V and rz = 5Ω).
Vd on = 0.7V

D1, 110 Vac Vsec 这个字: Det

a) Analyzing the circuit and waveforms, which components are not working Justify.
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Then the components that were not working are replaced, answer :
b) What is the peak voltage (Vp) in the capacitor and in the zener? Justify.
c) What is the amplitude of the ripple voltage (Vrp) in the capacitor and in the zener? Justify

Answer 1

Simulation Model:

Assuming we have the secondary voltage as 17 V 60 Hz sinusoid readily available.

Capacitor Output:

Oscilloscope-XSC2 x Channel_B T1 T2 Reverse Time 34.848 ms 37.879 ms 3.030 ms Channel_A 12.525 V 15.525 V 3.000 V 2-11 Timebase Scale: 20 ms/Div X pos. (Div): 0 YAT Add B/A A/B Channel A Scale: 10 V/Div Y pos. (Div): 0 Channel B Scale: 5 V/Div Y pos. (Div): 0 Save Ext. trigger Trigger Edge: FZ A B Ext Level: 0 V Single Normal Auto None AC 0 DC AC 0 DC

Peak Voltage of the capacitor will be approximately 15.6 V.

The zener diode has Zener breakdown voltage of 5V with 5 ohm of parasitic resistance. So, the output Peak voltage across the Zener diode must not exceed 5.5 V any time.

Voltage across Zener Diode:

Oscilloscope-XSC1 Channel_B T1 T2 Reverse Time 52.462 ms 54.545 ms 2.083 ms Channel_A 5.164 V 5.408 V 243.638 mV T2-T1 Timebase Scale: 10 ms/Div X pos. (Div): 0 Y Add B/A A/B Channel A Scale: 2 V/Div Y pos. (Div): 0 AC 0 DC Channel B Scale: 5 V/DIV Y pos. (Div): 0 Save Ext. trigger Trigger Edge: FZ A B Ext Level: 0 V Single Normal Auto None AC 0 DC

Ripple Voltage of the Capacitor:

Ripple Voltage of the Zener Diode:

Verified using simulation.