555 Timer ic question please

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sleepypie
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555 Timer ic question please

Post by sleepypie »

Hi guys.
It's been a while since I have used a 555 timer and this should be really easy for you all but I kind of forgot how to use one. The question I have is, in the mono state, when you trigger the timer, will it stay in a state for the time that's set up regardless of if it is re-triggered or will the time restart before timing out? The 555 timer ic I'm used is the LM555 ic from TI, here's the link of this ic's introduction: https://www.apogeeweb.net/circuitry/LM5 ... sheet.html
Thanks in advance.
dyarker
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Re: 555 Timer ic question please

Post by dyarker »

It can be either way. Re-triggerable takes a couple transistors; one to discharge the timing capacitor to start the time over again.

Do you want re-triggerable?

Cheers,
Dale Y
sghioto
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Re: 555 Timer ic question please

Post by sghioto »

The direct answer to your question is YES as long as any additional triggers do not exceed the Delay Time.
dyarker
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Re: 555 Timer ic question please

Post by dyarker »

additional triggers do not exceed the Delay Time
Then the answer is NO. You want additional triggers during the delay ignored till after the delay, Then another trigger starts a new delay.

"Re-trigger" means the output could stay on forever, as long as triggers happen before the delay time since the previous trigger.

Cheers,
Dale Y
sghioto
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Re: 555 Timer ic question please

Post by sghioto »

dyarker wrote: Mon Mar 22, 2021 5:59 pm
You want additional triggers during the delay ignored till after the delay
Correct. That's what the TS asked, will additional triggers be ignored or extend the Delay time.
Answer: Yes the triggers will be ignored unless the triggers extend past the Delay time
NV 555 monostable timing chart.png
NV 555 monostable timing chart.png (4.1 KiB) Viewed 11037 times
dyarker
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Re: 555 Timer ic question please

Post by dyarker »

I asked "Do you want re-triggerable?"

He answered "Yes". Which is wrong based on rest of answer.

"Re-trigger" does not ignore triggers during time period.

You said the "yes" was to the "Ignore"; but that was not the question!

Please learn to READ before butting in!

Back to post 1 -
regardless of if it is re-triggered
If it is ignoring, then it is NOT re-triggered, just another trigger occured with no effect. Re-trigger restarts the time period.

So I explained and figured he is a newbie and didn't know yet. What's your excuse?

Thanks,
Dale Y
sghioto
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Re: 555 Timer ic question please

Post by sghioto »

dyarker wrote: Mon Mar 22, 2021 11:10 pm I asked "Do you want re-triggerable?"

He answered "Yes". Which is wrong based on rest of answer.
The TS never responded to your question.
I was responding to the question that the TS asked in post #1 not you.
Please learn to READ before butting in!
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CeaSaR
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Re: 555 Timer ic question please

Post by CeaSaR »

sleepypie wrote: Mon Mar 22, 2021 1:20 am Hi guys.
It's been a while since I have used a 555 timer and this should be really easy for you all but I kind of forgot how to use one. The question I have is, in the mono state, when you trigger the timer, will it stay in a state for the time that's set up regardless of if it is re-triggered or will the time restart before timing out? The 555 timer ic I'm used is the LM555 ic from TI, here's the link of this ic's introduction: https://www.apogeeweb.net/circuitry/LM5 ... sheet.html
Thanks in advance.
While you are waiting for the above fight to finish, perhaps a bit of reading might help pass the time.
https://www.electronics-tutorials.ws/wa ... timer.html

Dale and Steve, please focus on replying to the help asked. I know this past year has taken it's toll on all of us, but let's not let it permeate a place we've been for so long. Please?
Hey, what do I know?
sghioto
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Re: 555 Timer ic question please

Post by sghioto »

CeaSaR wrote: Tue Mar 23, 2021 11:31 am
sleepypie wrote: Mon Mar 22, 2021 1:20 am

Dale and Steve, please focus on replying to the help asked. I know this past year has taken it's toll on all of us, but let's not let it permeate a place we've been for so long. Please?
Agree, it was an honest misunderstanding. I apologize for not quoting the TS when I replied.
SG
dyarker
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Re: 555 Timer ic question please

Post by dyarker »

agreed!
Dale Y
wardrose1
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Re: 555 Timer ic question please

Post by wardrose1 »

Do you admit that 555 ic is very flammable?
I had to change a lot of ICs for my electrical practice cookie clicker.
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