Upon reaching its breakdown voltage, what characteristic does a DIAC exhibit?
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Answer: D. All of these
Explanation
Reaching its breakdown voltage causes a DIAC to exhibit a sudden drop in voltage across its terminals. This voltage snap-back creates a region of negative differential resistance in its characteristic curve. Avalanche breakdown occurs rapidly in both polarities, enabling symmetrical bidirectional triggering. A DIAC is a two-terminal bidirectional semiconductor trigger diode used with TRIACs. Negative resistance means voltage decreases as the conducted current through the device increases. Avalanche breakdown involves rapid carrier multiplication under high electric field strengths.
DIACs are widely used in phase-control circuits to trigger TRIAC gates consistently. Their sharp switching action ensures precise firing angles in lamp dimmers and heater controls. Understanding breakdown characteristics helps engineers design robust triggering networks. Listing only negative resistance ignores the critical avalanche condition and voltage snap-back. Mentioning only avalanche condition overlooks the resulting negative resistance and snap-back behavior. All of these is correct because breakdown encompasses avalanche, snap-back, and negative resistance.
- Subject
- Engineering
- Category
- Electrical Engineering
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- —
- Difficulty
- medium
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