Re: rise and fall time


"Joerg" <notthisjoergsch@xxxxxxxxxxxxxxxxxxxxx> wrote in message
news:EdyEe.6238$_%4.1894@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> Hello M. Smile,
>
>> No clock would be applied.
>> It is a cheap way I'm experimenting to send clock pulses or reset pulse
>> on the same line: clock input directly connected to this line and reset
>> input through a 1mS RC filter. Sending short pulses (14uS on/46uS off in
>> my case) would not be enough to rise significative voltage on reset input
>> after the RC filter but clock input would work as intended. On the other
>> hand, sending a long pulse (say 5mS to be sure) would rise voltage enough
>> at reset input to reset the counter.
>
> For greater peace of mind I would look into adding a CD40106 Schmitt
> inverter before each input. For the reset that would be after the RC
> filter. It is cheap. Just keep in mind that now the assertion levels will
> be inverted.
>
> I have done a lot of slope dependent and duration dependent switching with
> CD40106 chips. They are great.

I may consider this if it proves to be unreliable.
I'm just trying to do as much as possible with less chips, otherwise I go
with microcontrollers.

Thanks!
M.S.


> Regards, Joerg
>
> http://www.analogconsultants.com


.

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