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Decade counter w/ hex inverter - inverted output?

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R2-D2

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Decade counter w/ hex inverter - inverted LED output?

I want six LEDs sequentially counting from the 4017 decade counter and invert their states. For example, during the decade count, instead of the output LEDs being: off-off-on-off-off-off, I want the option to invert their states to be: on-on-off-on-on-on.

:mad::mad::):mad::mad::mad:
:):):mad::):):)

It looks like I need to use a 4049 hex inverter to the output of the decade counter to do this. I guess I connect each LED to its six outputs to invert their states. Seems it would work. Do I just connect a momentary switch to its supply voltage (pin 1) to invert the LEDs on its output? I'm going to experiment with this...

4000 series CMOS Logic ICs
 
Last edited:

jimlovell777

New Member
Why can't you just connect the LEDs reverse of normal to invert the output? Connect the 7th output to the reset pin to get six steps.
 

R2-D2

Member
I'll try that option. I also want the ability to invert the LEDs output with a switch. I don't think I can do that alone with the 4049 hex inverter.
 
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dougy83

Well-Known Member
I'll try that option. I also want the ability to invert the LEDs output with a switch.

you can use XOR gates to provide this option. Connect the 4017 outputs to 1 input of 6 XOR gates, and the value from the switch to the remaining inputs (tied together). When the switch connection gives a high value, the XOR gates will invert; otherwise they won't invert.
 

R2-D2

Member
XOR gates to invert LED lights...

Dougy83, interesting idea. That should definitely work. Thanks!
I'll also try with the 4049 inverter, but not sure with using a switch on that one.
Jeff
 
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