Overthinking a simple latching circuit

giovanni

giovanni

Well-known member
Hey guys, I vaguely remember taking a digital circuit class in college but nothing stuck with me apparently… I promised the kids that I would make them a little box with some pots and switches and LEDs that they can play with (my daughter has been calling it her Time Machine [not sure why my phone capitalized that but I’m too lazy to change it]). The trick is that they love momentary buttons (like tact switches or similar) and I decided we could use them to turn some LEDs on and off. First push, on, second push, off. So that’s a latching flip flop circuit right? I have been trying to figure out the easiest way to make a circuit with, say, 2-3 of these and I’m having a hard time finding the right solution. I think I may have option paralysis after looking at too many examples online that do almost what I want (I think the closest is the first example from this).

So I am wondering if anybody on the forum has a suggestion of a circuit I can use for this. I don’t think I need a relay, I should be able to use a CMOS digital chip or something (I have a bunch from the 4000 series, one of those should work) and hopefully no need for multiple chips. I am open to using transistors too but I am trying to optimize for space and the fact I am not planning to use a PCB. Maybe vero board.

Suggestions are greatly appreciated!
 
Maybe something like a StompBox footswitch, push on/push off?

Or the latching circuit from a pedal that uses a momentary switch.
 
Last edited:
That said, after further research I ended up ordering some latching push buttons from Tayda. They are not as cool (and probably not as sturdy) as some of the metal momentary push buttons they have but it’ll do for a kids toy.
 
If you got some SPDT's you could wire them up two-way lightswitch style so there's a tiny bit of logic in there.

Relays can make cool clicking noises as well. You can wire them so they self-oscillate and they'll make a buzzing noise.
 
giovanni said:
Hey guys, I vaguely remember taking a digital circuit class in college but nothing stuck with me apparently… I promised the kids that I would make them a little box with some pots and switches and LEDs that they can play with (my daughter has been calling it her Time Machine [not sure why my phone capitalized that but I’m too lazy to change it]). The trick is that they love momentary buttons (like tact switches or similar) and I decided we could use them to turn some LEDs on and off. First push, on, second push, off. So that’s a latching flip flop circuit right? I have been trying to figure out the easiest way to make a circuit with, say, 2-3 of these and I’m having a hard time finding the right solution. I think I may have option paralysis after looking at too many examples online that do almost what I want (I think the closest is the first example from this).

So I am wondering if anybody on the forum has a suggestion of a circuit I can use for this. I don’t think I need a relay, I should be able to use a CMOS digital chip or something (I have a bunch from the 4000 series, one of those should work) and hopefully no need for multiple chips. I am open to using transistors too but I am trying to optimize for space and the fact I am not planning to use a PCB. Maybe vero board.

Suggestions are greatly appreciated!

Was reading through this while pausing on https://casinosanalyzer.com/free-slots-online/Sugar-Rush for a quick break. Your circuit idea makes sense, you’re not overthinking it. Latching is simple until you add LED indication. I’d test with a basic transistor switch first to see behavior.
Click to expand...
I am replying here so that I can keep track of this thread.
 
Last edited:
giovanni said:
And btw you can make three latching switches with one single chip which is not bad.
Click to expand...


THREE!

My oh my, you don't say... hmmm...


giovanni

Thread '3-way splitter'

I can’t believe I have another build report! I started this over the weekend and finished it tonight. I now realize that I’m more motivated when I have everything I need to finish a pedal which, in this case, I did, thanks to Robert’s excellent faceplate.

The build went very smoothly. It only took me maybe one hour to populate most components and then maybe a bit over one more to wire all the jacks. Maybe two. I wasn’t keeping track. But I am currently in a tiny groove which is exciting.

Besides Robert’s faceplate, I used silver aluminum Tayda knobs and a sand red enclosure drilled by...
  • Like
  • Love
  • This ROCKS!



Perfect!
 
You must log in or register to reply here.
Back
Top