Discrete Semiconductor Devices and Circuits

Clipper and Clamper Circuits

21 questions By Tony R. Kuphaldt

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Question 10 of 21

Sketch the shape of the output voltage waveform for this “clipper” circuit, assuming an ideal diode with no forward voltage drop:

Reveal answer

Notes:
This circuit is not difficult to analyze if you consider both half-cycles of the AC voltage source, one at a time. Ask your students to demonstrate this method of analysis, either individually or in groups, at the front of the classroom so everyone can see and understand.
Question 11 of 21

Predict how the operation of this clipper circuit will be affected as a result of the following faults. Consider each fault independently (i.e. one at a time, no multiple faults):

Diode D₁ fails open:

Diode D₁ fails shorted:

Resistor R₁ fails open:

Resistor R₁ fails shorted:

For each of these conditions, explain why the resulting effects will occur.

Reveal answer

Diode D₁ fails open: No output voltage at all.

Diode D₁ fails shorted: Full AC signal at output (no clipping at all).

Resistor R₁ fails open: No change (if diode is indeed ideal), but realistically there may not be much clipping if the receiving circuit has an extremely large input impedance.

Resistor R₁ fails shorted: No output voltage at all.

Notes:
The purpose of this question is to approach the domain of circuit troubleshooting from a perspective of knowing what the fault is, rather than only knowing what the symptoms are. Although this is not necessarily a realistic perspective, it helps students build the foundational knowledge necessary to diagnose a faulted circuit from empirical data. Questions such as this should be followed (eventually) by other questions asking students to identify likely faults based on measurements.
Question 12 of 21

Predict how the operation of this clipper circuit will be affected as a result of the following faults. Consider each fault independently (i.e. one at a time, no multiple faults):

Diode D₁ fails open:

Diode D₁ fails shorted:

Resistor R₁ fails open:

Resistor R₁ fails shorted:

For each of these conditions, explain why the resulting effects will occur.

Reveal answer

Diode D₁ fails open: Full AC signal at output (no clipping at all).

Diode D₁ fails shorted: No output voltage at all.

Resistor R₁ fails open: No output voltage at all.

Resistor R₁ fails shorted: Normal operation if source impedance is substantial, otherwise diode and/or source may be damaged by direct short every half-cycle.

Notes:
The purpose of this question is to approach the domain of circuit troubleshooting from a perspective of knowing what the fault is, rather than only knowing what the symptoms are. Although this is not necessarily a realistic perspective, it helps students build the foundational knowledge necessary to diagnose a faulted circuit from empirical data. Questions such as this should be followed (eventually) by other questions asking students to identify likely faults based on measurements.