PWM - Pulse width modulation. What a simple dimmer switch can teach us.

A PWM DC switching device. To us it might seem like a crude dimming device or a voltage regulator but it teaches us much more when fitted to an oscilloscope

About 70% duty which means 70% of the applied voltage gets out. Yet the source voltage is switched at the same applied input voltage. The only difference is time

Approx 5% duty cycle , which is about 5% the applied voltage. Yet the source has not dropped at the peak of the square wave

100% duty.. This is full power and now it looks like a conventional DC supply.

PWM - pulse width modulation

We cant see it with our eyes... A voltmeter shows a lower or higher output voltage to the load and we just know its a dimmer switch. Hey its more than that.

Its a duty cycle control, maintaining the source power constantly but changing the switching speeds and this is what drives inverters. Too fast for us to see... but not for the oscilloscope.

Imagine switching both positive and negative feeds to create a sine wave , then chop the same feeds twice more at differing time intervals and you have 3 phase inverter output from one single phase DC supply.

Folks ... don't beat your brains out. it is just that simple to do. You see here you are looking at one positive signal switching which we call DC. No negative signal other than 0V. But give it a negative switch and it looks like a raw AC waveform. This is the basis of phase creation from +/- DC

You see an inverter gets to do both at the same time... And the world just got smaller for all of you , nothing is over complicated. Its just ON - OFF  high signal, low signal  positive on and negative on.
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Absolutely cool