Hi,

I need to design a circuit that with one push button I can toggle between 3 or 4 outputs.
It is very easy to do so with an MCU but I prefer to do it without, using discrete components, latch and/or 555 timers.

I know how to toggle between two outputs, using a soft latch circuit but I cannot figure out if it is possible to enhance this to toggle between more.

It should look something like this:

push button output
1 1
0 1
1 2
0 2
1 3
0 3
1 4
0 4

Any ideas will be appreciated.
Thanks

 

The circuit below uses the CD4017 to cycle between two outputs. If you connect pin 10 to D1 instead of pin 4, the button will cycle round outputs 0, 1, 2, and 3.
https://www.electroschematics.com/automatic-bathroom-light-switch/

 

Circuit posted on this site for archival purposes.



Switch debouncing and supply decoupling not shown.

 

Switch debouncing and supply decoupling not shown.

The CD4017 has a Schmitt-trigger clock input so all that's needed for switch debouncing is a series resistor (say 100kΩ) and a capacitor to ground (say 1μF).

 

Below is the LTspice simulation of the CD4017 circuit with switch debouncing added.
It's configured for a 4 sequential output.

Is that sequence satisfactory for your application?

 

Thanks guys.

This looks like an excellent solution for me.

 

Hi,

I need to design a circuit that with one push button I can toggle between 3 or 4 outputs.
It is very easy to do so with an MCU but I prefer to do it without, using discrete components, latch and/or 555 timers.

I know how to toggle between two outputs, using a soft latch circuit but I cannot figure out if it is possible to enhance this to toggle between more.

It should look something like this:

push button output
1 1
0 1
1 2
0 2
1 3
0 3
1 4
0 4

Any ideas will be appreciated.
Thanks

Go old school, use a series of multi-pole, single through relays. Along with a few cap's and resistors... you are working.

 

If you ever needed 16, 23...., 32 or 64 version PM me, easy solution for doing that. One chip.

Note, do not tie large value caps directly to cmos input pins. This is because a collapse of the
power supply has the cap discharging thru protection diodes on CMOS input, and excessive
current can flow. Insert a R, say 1k, between cap and CMOS input to limit that current.


Regards, Dana.