Forums » CircuitLab Feature Requests

Voltage and Current sources have phase-offset, great! But I miss duty-cycle for square waves.

This would be very helpful for all sorts of switched converters (buck, flyback, half/full-bridge etc.). Where the duty-cycle is the main control parameter.

If the duty-cycle could be controlled by a voltage, one could even model the feed-back loop, but that's a bonus.

P.S.: The "digital clock" has a duty cylce, but no phase. One really needs both.

Have you tried using the Voltage and Current sources set to a triangle wave, followed by a comparator?

The phase of the triangle wave will give you the phase of the pulse waveform and the reference voltage of the comparator will give you the duty cycle.

This is, of course, the basic core of a PWM in many SMPS topologies anyway.

The PWM Generator in the left hand component selection panel does a similar job.

:)

Never noticed the PWM component before! I rephrase my feature request to this:

Please add a phase parameter to the PWM component.

That would be just perfect.

And thanks for the workaround.

I want these features too.

1) Function Gen has Phase. Please add Duty-Cycle for square, sawtooth, and triangle waves.

2) Digital Clock has Duty-Cycle. Please add Phase.

3) PWM Generator controls Duty-Cycle. Please add Phase.

Yes, we can build circuits ourselves to do both Duty-Cycle and Phase, but it makes our circuits more messy, especially if we need multiple of these waveforms running in sync but with different phases and duty-cycles.