Simulating the movement pattern of an elevator using a class D chopper

[Fatima Hasan]

Homework Statement

Attached below.

Relevant Equations

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The question:

Here's my attempt:

However, I got stuck, I don't know what should be connected to the gate of the switches as the duty cycle changes in each case.
Should I insert a pulse generator with 0.5% duty cycle for the 1st case, another pulse generator with a duty cycle > 50% (for example 75%) for the 2nd case.
For the 3rd (from 6 to 8 sec), duty cycle= 0.5%
For the 4th (from 8 to 12 sec), duty cycle > 50% (eg. 75%) ,etc...
And then add them up and connect it to the gate of both switches?

Could someone please help me solving this problem.

 

[LightHero]

Yes, you are correct. You need to connect a pulse generator with a duty cycle of 0.5% to the gate of the switches for the first case, and a pulse generator with a duty cycle greater than 50% (for example, 75%) for the second case. For the third case (from 6 to 8 seconds), the duty cycle should be set to 0.5%, and for the fourth case (from 8 to 12 seconds), the duty cycle should be set to greater than 50% (such as 75%). Then, add them up and connect the sum to the gate of both switches.