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How do I set up a monostable 555? Answered

Ya, i've been searching around and what I don't understand is how to make the pulse for the trigger.  Its has to be less than 1/3 the supply voltage right?  But how do I achieve this?  THANKS  

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steveastrouk
steveastrouk

Best Answer 10 years ago

Well, where's the trigger cominfg FROM ?

A simple resistive divider will make it happen, but you need to know what the peak of the trigger voltage is going to be.

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junits15
junits15

Answer 10 years ago

the trigger is supposed to be a transistor that will be triggered by sound from a microphone. However for testing I'm using a pushbutton switch, what do you mean by the peak of the trigger voltage? Also Im beginning to think I may have burned my chip out because one time it became extremely hot, but I'm not going to rule out the fact I probably built the circuit wrong

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steveastrouk
steveastrouk

Answer 10 years ago

Sounds like it might be damaged, though 555s are pretty robust beasties.

Steve

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junits15
junits15

Answer 10 years ago

I'm thinking the same because I've tried tons of different circuits and none of them worked, it doesnt seem to be doing anything, do you know how I could test to see if its working still?

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steveastrouk
steveastrouk

Answer 10 years ago

I think, for the price, I'd just swap it out for a new one.

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junits15
junits15

Answer 10 years ago

Ok thanks!