Difficulty: Easy
Correct Answer: positive and negative ramps of equal value
Explanation:
Introduction:
A triangle wave is a fundamental non-sinusoidal waveform used in modulation, timing, and function generators. Recognizing its time-domain structure helps in understanding its frequency spectrum and how it is produced by integrator circuits.
Given Data / Assumptions:
Concept / Approach:
An ideal triangle wave consists of a linear rise followed by a linear fall of equal magnitude but opposite slope, repeating every period. This symmetry leads to a spectrum with only odd harmonics whose amplitudes decrease with the square of harmonic number, but the time-domain hallmark is equal positive and negative ramps.
Step-by-Step Solution:
Consider a comparator–integrator oscillator: constant comparator output levels drive the integrator with constant current.Constant current through the timing capacitor causes voltage to change linearly: dv/dt = I/C (constant).When thresholds are crossed, polarity reverses and the slope changes sign but not magnitude.Thus, the output is equal-magnitude positive and negative ramps forming a symmetric triangle.
Verification / Alternative check:
On an oscilloscope, measuring rise time and fall time over the same vertical excursion shows equality for an ideal triangle, validating equal ramp magnitudes and durations.
Why Other Options Are Wrong:
Common Pitfalls:
Final Answer:
positive and negative ramps of equal value
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