normally closed momentary switch and flip-flop

[Dimitree]

hello everyone
I was wondering if I can use a normally closed momentary SPST switch in the flip flop circuit that R.G. describes in his site here:

http://www.geofex.com/article_folders/cd4053/cd4053.htm

specifically, I'd like to use the second circuit (the one that uses hex inverters).
It is possible, with some modifications, or pratically impossible without altering the whole circuit?

also, I was wondering if, for some particular reasons, NC switches were more prone to bouncing, so if I need to address this issue too.

[R.G.]

That circuit does not work well with NC switches. The reason is that the state it's switching to is "stored" in that capacitor that the switch connects to, and the switch making the contact from NO is what makes the circuit work. There are ways around this, but they all involve adding more stuff to the circuit, and adding other issues that make it less desirable.

IMHO, it's possible, but not terribly practical.

NC switches are not more or less prone to bouncing than NO switches. All of them bounce to a degree determined by the micro-details of their mechanics, when they make. NC switches are probably less prone to bouncing when they OPEN, but it's not unheard of for them to do this, again depending on the mechanics.

Finally, one of the really screamingly good issues of this circuit as it exists is that it debounces the NO switch while it does its flipflop action.

[Dimitree]

thank you R.G.,
Then I will use NO switches instead of NC.

[plexi12000]

hope you dont mind me cuttin in to ask a dumb question.  i always wondered what people use the "momentary" switches for? what are the common applications?

[GibsonGM]

Not a dumb question, Plexi...a real one     A momentary switch 'reverses its state' when you press it.  So, normally open >> you press switch >> it closes and then, when you let your finger up, it returns to normally open.   So, it is closed for a 'moment', which you provide by pressing it.
Like a door bell button.

Common apps:  doorbell    Changing the state of a logic circuit, with a buffering circuit in between to make the switching 'sharp' (bounceless)...any place you need a quick pulse to start something, but it might be best if that trigger was not present for very long (for lack of a better way to express this). 

Remember: the "other" kind of switching is LATCHING...when you throw the switch, it stays in that position (which may make parts burn out, or your application difficult because a momentary "resets" automatically).  So, we're just talking about "Blip!" vs  " I AM ON NOW AND STAYING ON".

[rumbletone]

hope you dont mind me cuttin in to ask a dumb question.  i always wondered what people use the "momentary" switches for? what are the common applications?

In pedals, they are often used for (among other things) tap tempo footswitches.

[plexi12000]

thanks guys....i appreciate it!  i could never think of a reason to use one- lol  just wondering 

i alwys feel like a total retard.....everyone on here seems like friggen scientists...talkin formulas and shit! hahahaha

hell.....i can't even get my fuzz pedal to work! LOL

GibsonGM---- i happened to notice your avatar or whatever the hell you call them....listing your gear?  says you have a "blues breaker" and a "guv'nor" pedal??

Are those both straight up "distortion" pedals?  i never heard any in person.  what do you like and/or don't like about them?   i was thinking of maybe building one.

[Transmogrifox]

This one works gracefully with NC switches.  I got a great deal on a batch of 25 NC momentary switches so that's what I use with this circuit.

The little "bug" in it is that the pedal state changes when you release the pedal instead of when you stomp it.  If that is acceptable, then that will work.

If you're going to buy switches, buy NO because I haven't seen much for latching toggles based upon an NC.

Also notice this one is designed to work with a relay coil of some sort.  If you're just driving JFET circuits or whatever else, then you can replace the coil with a resistor and it will work.

[GibsonGM]

  says you have a "blues breaker" and a "guv'nor" pedal??

Are those both straight up "distortion" pedals?  i never heard any in person.  what do you like and/or don't like about them?   i was thinking of maybe building one.

Hey Plexi - the Bluesbreaker is really a ... blues pedal   It's an overdrive - it doesn't give a lot of distortion...it's gritty.  The Guvnor, OTOH, is pretty wild (IMO) - that's my go-to for a lot of stuff, Guns N Roses.  I omit the tone stack and just use a simple high cut at the output and get a lot more level out of it.   It's a glorified Distortion +, which you could build in short order to see what opamp-based distortions are like... 

You might like it?


I love latching relays, they are massively useful! 

[plexi12000]

GibsonGM...... ok, copy that.  i always heard the guv was pretty righteous.  good for G-n-R?  hmm....yeah, i can dig that!! lol   thanks buddy- i'll keep that in mind.  and the tone stack "delete".

[GibsonGM]

Breadboard it (it's not too hard if you go slow) and just take your output after the clipping diodes - throw a 100k pot there and you're good to go (for testing).   You may want to add a LPF before that, as I mentioned, to tame some highs.

[duck_arse]

hey plexi - happy 100 (+1).

[plexi12000]

Breadboard it (it's not too hard if you go slow) and just take your output after the clipping diodes - throw a 100k pot there and you're good to go (for testing).   You may want to add a LPF before that, as I mentioned, to tame some highs.

well......you lost me already Gibby!!!  hahaha  i dont know that much yet. 

duck-arse----  100?