Re: Want independant pulse width variation on + and - side of gnd;square wave of about 1kHz

From: jtaylor (jtaylor_at_hfx.deletethis.andara.com)
Date: 10/14/04 

Date: Thu, 14 Oct 2004 15:06:03 -0300

Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> wrote in message
news:7jetm01ar7l285qog0fso67k4okgc1fbqc@4ax.com...
> On Thu, 14 Oct 2004 14:28:22 -0300, the renowned "jtaylor"
> <jtaylor@hfx.deletethis.andara.com> wrote:
>
> >
> >John Popelish <jpopelish@rica.net> wrote in message
> >news:416EA3A9.6BA8F9E2@rica.net...
> >>
> >> How can the positive and negative parts both be 100% (duty cycle?) at
> >> the same time or 0% at the same time (infinite frequency)?
> >>
> >> Or are you saying that you want the on time to be variable from some
> >> small time to some maximum time and also the off time to be variable
> >> from some small time to some maximum time and variations in the
> >> duration of one state does not affect the duration of the other state?
> >
> >
> >Um, no. I want ground in the middle, and the other line to go from say
+5v
> >to -5v, at about 1kHz, with the + pulse varying in width, and the - pulse
> >varying in width.
>
> You can consider connecting the "GROUND" pin on the 555 to -5V. It'll
> never know the difference, you know.
>

Yes, but how would I get a (say) drop from ground to -5V lasting for
1/4000th second , returning to 0V for 1/4000th second (1/2 cycle of 1kHz at
50%) followed by (say) a rise from 0V to +5V lasting for 1/8000th second,
returning to 0V for 3/8000ths of a scond (1/2 cycle of 1Khz at 25%)?