[sdiy] CMOS mystery

[KD KD]

A voltage divider (larger resistors) and let internal diodes shunt
negative side and/or add a diode for the -0.7V whatever.

2018-07-07 2:16 GMT+02:00, David G Dixon <dixon at mail.ubc.ca>:
> Hey Team,
> The result:  No change.  The CD4024BE chip still does not work, but the
> other ones do.  I've come to the conclusion that these CD4024BE chips are
> just defective somehow.  The funny thing is that I'm only using the Q1
> output, and it looks fine on the scope, but it obviously is doing something
> very weird to the subsequent logic gates.
>
> I'm still stumped, but I've learned a couple of important lessons.
>
> So, I'm thinking that it would have been OK just to put the 10k
> current-limiting resistor in between the raw square wave output and the
> 4024  CLK input, and let the on-board protection diode limit the voltage, with a
> paltry 500uA of current flowing through it, which isn't going to hurt
> anything.  Am I thinking about this correctly, or is it just a whole lot
> harder and more sophisticated than my tiny brain is capable of conceiving?