"three phase" sig gen?

[Martin Czech]

> 
> I was wondering if any of you gurus could help me out with a
> simple cct for a signal generator. The outputs I want to be
> like this:
> 
>      __
> 1.__|  |______|
>         __
> 2._____|  |____
>            __
> 3.________|  |_
> 

There are CMOS decoder chips. I think 4,8, and 10 steps.  Combined with
a counter you can build a little sequenzer that produces any pattern you
want. For simplicity you can OR the outputs with diodes, before going
to the output stage (load requirements).  A unused step output can be
used as asynchronous reset, to shorten the thing to the wanted number
of steps.  If you want glitch free performance you'll have to sample
the ORed output with another FF.


BTW, this way you can replace a rotary switch with an up (or up/down)
button.  You can have as many positions as you want. Problem is: no
memory after power down. The ELV generator I build over christmas uses
something like this for all switches (of course only voltage can be
switched, i.e. very little currents).


m.c. (no guru, just a simple engineer)