Proposal for an electonic hi/low switch with pushbuttons

cheese_nucleus · Joined: Dec 22, 2009 Posts: 24 Location: germany

i want to build a universal switch module to give out hi / lo signals, for example to start / stop / reset 4040 counters and 4051 sequencers. i want to use momentary pushbuttons to do this. yes, i know, toggle switches would be the easiest way for this task, but i think a momentary pushbutton is more intuitive for starting/stopping sequencers.
i tried to build the circuit, attached to this thread (found on this website http://talkingelectronics.com/projects/TouchSwitch/TouchSwitch-1.html ). it's a toggle touch switch, using a 4049. the switch's output changes to high on one push, on the next, it changes back to low. an inverted output is also available. this switch is originally planned as a touch switch. i found it very unreliable, when i tested it.

so my question is: does anybody have an idea how to realize the same function, but with more reliability and maybe with less parts used?

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4049 toggle touch switch

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Kabzoer · Joined: Feb 07, 2011 Posts: 78 Location: Belgium

You can use a T flip-flop to toggle, as far as i know...

cheese_nucleus · Joined: Dec 22, 2009 Posts: 24 Location: germany

hey!

after some more hours of research, i found these schematics.

(source is http://ferromel.de/tronic_271.htm )

i'll breadboard the circuit on the left (bild 7) maybe tonight

cheese nucleus

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Kabzoer · Joined: Feb 07, 2011 Posts: 78 Location: Belgium

Yeah, I think the last one is JK flipflop wired as a T flipflop.

cheese_nucleus · Joined: Dec 22, 2009 Posts: 24 Location: germany

ok, so i breadboarded the 4011 circuit on the left today and it works perfectly. no delay and no failures like on the 4049 version!

richardc64 · Posted: Wed Mar 16, 2011 2:23 pm Post subject:

Since the 4011s are connected as inverters, each with both inputs tied together, you should be able to get 3 such circuits from one 4069.

cheese_nucleus · Joined: Dec 22, 2009 Posts: 24 Location: germany

ok, that would be the circuit in the middle. 4069 and 4049 can be used indentically, am i right?

richardc64 · Posted: Thu Mar 17, 2011 2:31 pm Post subject:

Kabzoer · Joined: Feb 07, 2011 Posts: 78 Location: Belgium

What is the difference between 4069 and a 4049? There must be a difference because the schematics in the datasheet are different.

-minus- · Joined: Oct 26, 2008 Posts: 718 Audio files: 13

Well to start with, they are powered from different pins. This means that if you were substituting one for the other in a circuit, you would have to change the way the IC is powered.

richardc64 · Posted: Fri Mar 18, 2011 12:30 pm Post subject:

artifus · Joined: Jan 23, 2011 Posts: 11 Location: uk

4069:4049 module - easily swap two popular CMOS chips

Draal · Posted: Mon Mar 21, 2011 1:59 pm Post subject: