555 Timer Rapid Flashing

Question

Hey everyone.

I've been trying to use a 555 timer in one of my projects but I'm not sure how.

I've never used one before so I'm not sure if when I'm using it I'm setting up the circuit wrong or the chip is broken.

If you guys could help me, I'm just trying to make a rapid blinking circuit.

NOTE: My end goal is to have the output blink rapidly while a button is being pressed and do nothing when it's not. If there is a better way to do this than a 555 timer, please let me know.

Thanks.

P.S. I know this isn't really in the right section but it was the closest I could find.

clem57 · Accepted Answer

50 - 555 Circuits 555 Delay Times: C R 1 = 100k R 2 = 100k R 1 = 470k R 2 = 470k R 1 = 1M R 2 = 1M 10µ 2.2sec 10 sec 22sec 100 µ 22sec 10 0sec 220sec 470 µ 100sec 50 0sec 1000sec So the best you can do is 2.2 secs with the corner above. Bad news is the circuit uses power at 10mA.

clem57 · Answer

Pin 3 is output and the LED looks backward. Also the LED should go to gnd.

mcb1 · Answer

Pin 3 is output 
 I think you'll find Pin3 is a digital output, so it should go low when in the OFF state. http://www.555-timer-circuits.com/using-the-output.html I see nothing wrong with your schematic. What is the value of C1, and if it is an electrolytic did you have the - side to ground ? It is worth adding a 1nF or similar across pin 5 to ground ... think of it as insurance . For any digital circuit it is always a good idea to add a 470uF -1000uF capacitor PLUS a 100nF (0.1uF) across the supply rails close to the chip to stop the spikes causing unwanted issues. Mark

555 Timer Rapid Flashing

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