🚀 go-pugleaf

In article <1992Sep11.233617.12368@seanews.akita.com> finneyk@seanews.akita.com (Ken Finney) writes:
>From: finneyk@seanews.akita.com (Ken Finney)
>Subject: 120 HZ oscillator query
>Date: Fri, 11 Sep 1992 23:36:17 GMT
>
>I'm in need of an oscillator that puts out two square waves, 
>180 degrees out of phase, each one 60 Hz and 50% duty cycle.  
>My original idea was to use a MM5369 17 stage divider (with a
>7.15 MHz crystal it would generate a 120 Hz output) to drive
>a flip-flop to generate the two 60 Hz wave forms.  Unfortunately,
>the MM5369 doesn't produce a 50% duty cycle output.  So, does
>anyone know of a IC (or simple (ie: cheap) circuit) that is 
>designed to produce the signals I'm looking for?
> 
>Wave form A
>      |------|      |------|      |------|      |------|
>------|      |------|      |------|      |------|      |------
> 
>Wave form B
>------|      |------|      |------|      |------|
>      |------|      |------|      |------|      |------
> 
>Note: The "High" times of the two waveforms must not overlap,
>and it would be even nicer if they have a "break before make"
>characteristic.
> 
> 

Generate your clock at 240 Hz and run it through an edge triggered
D-type flipflop.  There is no way to guarantee simultaneous transition
though and Break before make means you don't really want a 50% duty cycle
anyway.  If you really want break before make, you can either use a
one-shot on each output (bad practice) or you can control the time when
each output is high and both are low by counting them in two counter
chains from the master clock.

--
Larry                                   |   Thunder makes all the noise;
                                        |   lightning gets the job done.
larryd@milton.washington.edu
I have my opinion; the university has its own.