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Is it possible to shift the phase of a square wave (which is generated by an Arduino) with passive components?
I have a 0 to 12V square wave that I would like to split into several phases. The idea is to send the original square wave to load 1, and a 60° shift to load 2, an additional 60° shift to load 3, and so on until I've got 360°.
I also have a 0 to -12 square wave that I would like to apply this to as well.
Use a 6 bit Johnson counter and drive that with a frequency 12x higher than what you want. The counter will generate 6 equally spaced, phase shifted, divided output square waves.
You could use a "Delay-Line" chip, but you still need active components to do the actual switching.
However, you have not stated whether your frequency is fixed or variable, and I suspect the latter is much more likely.
If so, you need to generate the signals from the MICRO individually, possibly with the addition of a multiplexer chip external to the micro if you need more outputs.
Rather than shifting a square wave, you could generate a faster square wave and frequency divide it. If you start each divider in a different state, they will have different phases once up and running. Here, you'd likely be best off with a fundamental at 6x the intended frequency, three divide-by-6 circuits to get the 0, 60 and 120 phases, then three not gates to get the other three phases. Be careful to make sure the div6 circuits keep a 50% duty cycle, if that's important for your application. Doing div3 then div2 would probably be a good approach.
It's not based on passives, but it only requires a few fairly basic logic chips. It should work for a very wide range of frequencies, and it will keep the phase angles very accurate.
You can generate adjustable phase shifted square waves using Arduino Uno, Nano or Mega2560 16-bit timers. The phase-shift range is 180 degrees.
The Nano-Uno boards can output only 2 channels (Timer-1) while the Mega2560 can do 3 channels (Timers 1,3,4 and 5).
There's a demo project at Runtime Micro covering parts, diagram and code listing (and video).
BTW, if you set a 2560's timer channels for 0, 60, 120 and add inverters, it might be possible to generate a 6 phase (BLDC motor?) series. I haven't tried it -- just a thought.
full-disclosure: I'm the author of the demo project.
