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How would I increase the flash rate of an LED?

  1. Oct 4, 2009 #1
    I created an led flasher using a 555 IC, 2 1k Ohm & 1 100 Ohm resistor, and 1 1000uF and 1 .01 uF capacitor. If you need to know exactly how it's wired up I can make a schematic. My question is how would I increase the flash rate? I need a flash of about 3(up to 5) per second.

    As you can tell I don't know as much as I should but I'm going to learn.
  2. jcsd
  3. Oct 4, 2009 #2


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    Science Advisor

    You would reduce the size of that 1000 uF capacitor by replacing it with a smaller one.

    Actually, you might like to have a look at this site:


    Under "555 Astable" there is a formula and a table for choosing component values.
    (Note the formula uses Farads as the unit of capacitance. 1 uF is 0.000 001 Farads).

    For resistors of 10 K and 100 K and a capacitor of 1 uF you get a flash rate of 6.8 times a second (6.8 Hz). So you could vary these a little to get the rate you want.

    Google gives a lot of information sites about this chip.
  4. Oct 4, 2009 #3
    Alright, thanks! I was probably too specific when googling it. Thanks for that site too!
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