I don't have an example made up but if you put a power on reset circuit on the reset line and tied the Q0not output to hi trigger input it should go astable but only be in the reset state for about 50 ns. On power on it comes up reset, triggering it. When the timing times out Q-not goes high again, clocking it ...I don't think I ever tried it since I don't have it in a drawing, but in theory it should work.I would like to use 1/2 for retrig. monostable and 1/2 for astable if its possible.
Or find a dual timer that does both. ~12v
555/556 type isn't a good choice for retriggering. IMO
What is your goal and what are the constraints. Any reason for limiting to a single chip?I would like to use 1/2 for retrig. monostable and 1/2 for astable if its possible.
Or find a dual timer that does both. ~12v
555/556 type isn't a good choice for retriggering. IMO
Nice find. Very interesting things in there. I have been looking for the answer to @inwo 's question for a long time and I assumed it couldn't be done.If you are looking for how to connect the MC14538 as an astable, this might help (you may want the whole application note, see link below):
View attachment 110234
Source: Fairchild AN366 (available here: http://www.scarpaz.com/Documents/AN-366.pdf)
As just an FYI, MC1xxxx numbers are usually equivalent to NNxxxx . That is, to find circuits for MC14538, try searching on CD4538 or any other chip with just 4538 in its ID.
John
I'll try that.Here's a way you can use 1/2 a CD4538 as an astable :-
View attachment 110239
An exercise in kiss.What is your goal and what are the constraints. Any reason for limiting to a single chip?
Have you changed your mind? KISSI would like to use 1/2 for retrig. monostable and 1/2 for astable if its possible.
Or find a dual timer that does both. ~12v
555/556 type isn't a good choice for retriggering. IMO
Is there an easy way to retrigger 555 (1/2-556)without more active components?Have you changed your mind? KISS
John
14538 same?Here's a way you can use 1/2 a CD4538 as an astable :-
View attachment 110239
Yes, the MC14538 is the same as CD4538 or HEF4538.
Use appropriate R and C values; the ones in the sim are merely for proof-of-concept.I'll try that.
Please start by reading post #5.Is there an easy way to retrigger 555 (1/2-556)without more active components?
Heck, maybe I can do the whole thing with one 555.
I'm open to suggestions.
I didn't check the link, as I was aware of that method which requires more gates and both halves.Please start by reading post #5.
John
Would you be willing to add a monostable half in the sim?Use appropriate R and C values; the ones in the sim are merely for proof-of-concept.
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