Figuring out 555

200

02:26:13

I'm attempting to figure this out for the thousandth time.

published 4 years ago

wyoelk

4 years ago

Maybe one of these will help _ _ http://everycircuit.com/circuit/5212107531091968 or http://everycircuit.com/circuit/5997908791656448

startrooper393

4 years ago

what are you trying to do? You are just picking up random npoise in your circuit. Please google some simple 555 LED blink circuits. 2 and 6 can go to the point in between the cap and 500 ohm resistor and 7 between the resistors, but your connection to 4 and 8 should go directly to power.

BillyT

4 years ago

Check the specifications on the data sheet, it will recommend a minimum of 1k resistors on the timing inputs. And look at this circuit as a basic starting point. http://everycircuit.com/circuit/4940729488769024

startrooper393

4 years ago

TI does not have a restriction in their data sheet for timing resistors, in fact, one of their examples is for the sum of the timing resistors to be 1k. But, Billy is right when he cautions you about small resistors, not a good practice in general. 10 ohm on the LED is not good. You are essentially shorting the LED. Change it to 1k if you want it to do what is should be doing. But look at Billy's circuit, it's perfect.

cjdelphi

4 years ago

the 555 timer relies on a timing capacitor, you essentially charge the cap, when it gets full, the 555 drains the capacitor and when it reaches low pin 2 triggers iff

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