Couple questions regarding handling the inputs to digital ICs (the chips I'm using are all in the CD4xxx series).
1. I have a project where I'm using a 4013 as a latch, and I want it to come up in the unset state when I power it on. I'm using this arrangement, which seems to work OK:
Question is, what values of R and C would be best here? (I don't mean super-optimized, just what will accomplish what I want, which is a reliable reset.) The trade-off here seems to be between A) a small C giving a shorter pulse vs a larger C, and B) a small R giving a faster pulse but loading the input more.
Basically, are these values in the ballpark?
Yes, yes, I know there are probably better ways to do this, like a one-shot, a 555 or something, but I'd rather keep this as simple as possible and not have to add another chip. It's not a precision application.
2. In the same project I'm setting the flip-flop by using a pushbutton switch connected to the set input. Since there's nothing else connected (no other gate), do I need to add a resistor to ground so that this input doesn't float when the switch is open? Would the same (4.7K) value be good here?
(Anticipating replies: no, debouncing isn't needed here. Multiple pulses don't matter.)
1. I have a project where I'm using a 4013 as a latch, and I want it to come up in the unset state when I power it on. I'm using this arrangement, which seems to work OK:
Question is, what values of R and C would be best here? (I don't mean super-optimized, just what will accomplish what I want, which is a reliable reset.) The trade-off here seems to be between A) a small C giving a shorter pulse vs a larger C, and B) a small R giving a faster pulse but loading the input more.
Basically, are these values in the ballpark?
Yes, yes, I know there are probably better ways to do this, like a one-shot, a 555 or something, but I'd rather keep this as simple as possible and not have to add another chip. It's not a precision application.
2. In the same project I'm setting the flip-flop by using a pushbutton switch connected to the set input. Since there's nothing else connected (no other gate), do I need to add a resistor to ground so that this input doesn't float when the switch is open? Would the same (4.7K) value be good here?
(Anticipating replies: no, debouncing isn't needed here. Multiple pulses don't matter.)