signal inversion question (4017 + 4049 + 4066)

Thread Starter

NOISEBOB

Joined Jul 7, 2019
41
Follow-up question to a previous question...


I have this circuit here:
stepping.png

It works pretty well.. I connect oscillators to the gates of the 4066 and the 4017 turns them on and off by sending out a HIGH signal sequentially.

Easy...

This means that the gates are at state LOW by default. Which made me think, why not do the same trick, just inverted, by running all the Q-signals through a 4049?

Wouldn't that make the default state of the gates of the 4066 to HIGH and every count of the 4017 to LOW?

...and thus create some kind of strange sequential muting machine?stepping.png
 

eetech00

Joined Jun 8, 2013
2,185
HI

Each "switch" in the 4066 is the same as a spst switch contact. The 4017 output is controlling the state of the "contact".
A high to the 4066 control pin closes the switch contact. A low opens the switch contact.

If you place an inverter between the 4017 output and the 4066 control pin, you will reverse the control of the switch.
A high output from the 4017 will open the switch, a low output will close the switch.
 

Ian0

Joined Aug 7, 2020
1,158
Follow-up question to a previous question...


I have this circuit here:
View attachment 223490

It works pretty well.. I connect oscillators to the gates of the 4066 and the 4017 turns them on and off by sending out a HIGH signal sequentially.

Easy...

This means that the gates are at state LOW by default. Which made me think, why not do the same trick, just inverted, by running all the Q-signals through a 4049?

Wouldn't that make the default state of the gates of the 4066 to HIGH and every count of the 4017 to LOW?

...and thus create some kind of strange sequential muting machine?View attachment 223489
Yes, that is exactly what it will do. At any time, three signals will be ON and one will be OFF.
By the way, D2 shouldn't be there: Q4 should go directly to reset.
 

Thread Starter

NOISEBOB

Joined Jul 7, 2019
41
The outputs from a CD4017 are not analog, they are digital. Then why are you using analog switches instead of digital switches?
Well.. partly because i had them at hand. And also because I'm new in this cmos thing

I like the idea of being able to sequence anything...

What ic would I want to use for digital switching?
 

Ian0

Joined Aug 7, 2020
1,158
It looks OK to me. Digital outputs from the 4017 going to digital "control"inputs to the 4066. Either direct or via an inverter.
Analogue signals to the analogue inputs to the 4066. What's the problem?
 

Thread Starter

NOISEBOB

Joined Jul 7, 2019
41
thanks everyone. i breadboarded it and of course it works as expected.

yet again, i'm surprised how simple (LOGICAL) it is...
 
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