I'm confused as I have seen a triangle waveform referred to in terms of PWM but a triangle waveform does not actually modulate the pulse width.
Is a triangle waveform a type of pulse width modulation?
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\$\begingroup\$ Are you asking if a triangle signal can be generated using PWM? Or if triangle waveform can be used as PWM-like carrier? \$\endgroup\$Eugene Sh.– Eugene Sh.2019-12-05 16:28:54 +00:00Commented Dec 5, 2019 at 16:28
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4\$\begingroup\$ A real pulse width modulated signal can sometimes look triangular due to limitations in rise and fall times but, theoretically no. \$\endgroup\$Andy aka– Andy aka2019-12-05 16:31:53 +00:00Commented Dec 5, 2019 at 16:31
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1\$\begingroup\$ Good question ... \$\endgroup\$Mitu Raj– Mitu Raj2019-12-05 16:38:21 +00:00Commented Dec 5, 2019 at 16:38
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1\$\begingroup\$ Perhaps you've seen a triangle waveform compared with the analog input signal to create a PWM output? A triangle waveform generator block plus comparator block does the PWM trick. \$\endgroup\$glen_geek– glen_geek2019-12-05 16:40:32 +00:00Commented Dec 5, 2019 at 16:40
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1\$\begingroup\$ In the early days of inverters (switch mode power supplies), a fixed frequency triangular waveform was used as the base switching frequency. That analog waveform was compared to a fed-back version of the output - an error term. The output of that comparator was the PWM signal that was used to drive the switching transistors. What glen_geek said. \$\endgroup\$SteveSh– SteveSh2019-12-05 16:44:20 +00:00Commented Dec 5, 2019 at 16:44
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3 Answers
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Is a triangle waveform a type of pulse width modulation?
No, without pulse widths, there can't be a PWM.
Especially: Since the average of the triangle waveform is constant / can't be parameterized, there's nothing to modulate.
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\$\begingroup\$ Thank you. That's what I though, it's really strange to see it referred to as a PWM. I'm going to accept this as true unless someone gives a solid reason why it is false. \$\endgroup\$SeanJ– SeanJ2019-12-06 21:57:23 +00:00Commented Dec 6, 2019 at 21:57
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The comparison of a triangle wave to a sine wave is a technique that has been used to generate a pwm waveform that simulates a sine wave.
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Is a triangle waveform a type of pulse width modulation?
Close .
It is the Modulator which has a binary output by comparing an analog voltage.
It is can also be done with a sawtooth waveform which is often harder to generate at high frequency.
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1\$\begingroup\$ I assume that using a triangle vs sawtooth wave generate PWM that is different, but still "close enough", that the average duty cycles are the same? \$\endgroup\$Steve– Steve2019-12-06 06:54:50 +00:00Commented Dec 6, 2019 at 6:54