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Simple Frequency Scaler and Phase Shifter

I am working on a little hobby project over the summer, and I need some sort of non-integer Frequency Scaler (or Counter) and a Phase Shifter. Unfortunately I don't know of any easy way to do what I need to do, and could use some general advice to figure out the best way to handle it.

The input signal would likely be less than 500hz, either Square-wave or Sine-wave (I can easily generate either). I am looking for the ability to scale the input signal over the full scale of Plus or Minus ~10%, and would like to be able to phase shift the signal a full 180 degrees in either direction. The output signal can also be either Square-wave or Sine-Wave. The key feature I'm looking for here is stability: I don't really care how accurate or linear the circuit res ponce is, but ideally I want the output signal to be as stable as possible.

For the Frequency Scaler I have been looking at a Frequency-To-Voltage Converter, Voltage adder, Voltage-To-Frequency Converter configuration. Unfortunate all of the converters I've been looking at don't seem to be very happy at such low frequencies. There is also the problem of maintaining calibration between the two converters.

The Phase Shifter has proven to be significantly more difficult. The only idea I've managed to come up with so far is to feed a square-wave input signal into an integrator, then trigger a new square-wave off the triangle-wave that comes out of the integrator. While I think this should work, there has got to be a better way.

I would greatly appreciate any ideas or suggestions.

Thanks

-Sunwatch

Reply to
SunWatch
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I barely remember the crappy digital phase shifter I made 10 years ago.. I used two 555 timers and a dual pot. D from BC

Reply to
D from BC
** Sun stroked Groper Alert !

** The +/-10% frequency variation can be done with a "digital pitch shifter" - buy one at any music shop that sells electric guitars and accessories. Or pick one up on Ebay, of course.

Once the pitch of a signal has been shifted this way - no phase relationship with the original is left.

........ Phil

Reply to
Phil Allison

One way to do it is to have sin() and cos() outputs on your generator and two pots to give each a gain from -1.0 to +1.0

Do you need to add a frequency or multiply the frequency by some amount?

Imagine the pots of the above suggestion were varied so that the phase was constantly advanced with time. This would give the adding of a frequency. A couple more sin() and cos() signals driving a multiplier or fader circuit would do it.

You can also use a PLL like the HC4046 to multiply the signal way up in frequency and then divide it down by a slightly different factor.

The other solution is the classic "use a PIC" sort of answer. A PIC can measure the period of a signal on its input and make one with a different period on its output.

Reply to
MooseFET

In -+-/\\/\\---+----/\\/\\---- ! ! ! ! --!-\\ ! ! POT ! >------+---- Out --\\/\\--+---!+/ ! --- --- ! GND

Reply to
MooseFET

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