Signal generator

With a not quite two year old hp 1320 and one toner refill I figure my cost/page at 8.9¢

Can you get two-sided printing done for less than that?

...Jim Thompson

Or, you could just hook the output of the amplifier to the input of the filter and leave out the PIC.

Sorry Ken but I dont see how that would work.

not quite, but the internet caff has really good printers, more than I can justify.

Anyway I spent the money on a breadmaking machine, much more fun.

martin

a écrit dans le message de news: snipped-for-privacy@i42g2000cwa.googlegroups.com...

DC

What's an oscillator?

he

Well sure it MIGHT oscilate but will it be stable? Be 7.07v? Or even be a sine wave?

the

Well sure it MIGHT oscilate but will it be stable? Be 7.07v? Or even be a sine wave?

Well, I'm sure Ken thought one could be not too dumb in looping the filter and amplifier, ie, designing enough phase rotation into the filter and enough loop gain, but not too much, providing a clean way to stabilise the amplitude... Then it WILL oscillate, will be clean, and stable. Of course one have to know what he does, but that's not rocket science...

Then I'm also sure that he was pulling your pants in reaction to the going-the-PIC-way-for-every-thing-before-thinking trend that leads to add some where they aren't required and add nothing, like there.

g a

True but thats not what he said.

Your probably right but in this case is him (and you) that has not done the thinking.

In article , Fred Bartoli wrote: [...]

Doubly so because the PIC doesn't have a real DAC. To make a good sinewave with it is more work than to make one without it.

The Cygnal version of the 8051 has a 8 bit DAC. It would be almost useful for this job.

In article , wrote: [...]

Can you be sure of that? I may have the whole design done but just didn't post it.

wrote:

You do not need a DAC. You simply produce a pwm waveform, then pass it through a low pass filter (reisistor capacitor) and your done.

I like the way you put "simply" before the part that involves writing software. :> Here let me try using that same sort of simply :>

You simply design a 400Hz oscillator and you're done. :>

Now to be serious for a second: The filter has to be a two pole filter at least if the sine wave is to be anything like acccurate. You have to design said filter. BTW: You also need gain to meet the OPs amplitude.

The Cygnal micro's DAC gives you the sinewave output with no filter design time.

If you are going to make a squarewave like signal that then is filtered to make the sine it is easier to not involve writing software.