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You can still make the circuits and blink the LEDS at different frequencies. This capacitor kit will give you plenty of different values.

In this instructable I will be exploring the astable oscillator and demonstrating a couple more interesting 555 oscillator circuits.

I would like to thank Mike63 for sending me a couple of useful formulas to calculate the frequency and the low time.

Frequency = 1 / (0.693 X C1 X (R1 + 2 X R2)) Low Time = 0.693 X C1 X R2

I googled the formulas and found them on the internet just as he sent them to me, but the answer seemed to have the decimal point in the wrong place. * A 10 uF capacitor is enough to get you started, but you will probably want to experiment with different values. I just grabbed a handful of different capacitors from my parts bin. Don't be afraid to experiment.

To construct these circuits you will need:

.. The formulas expect to have the capacitance in Farads. Or use what you have.

In my first Instructable about the 555 timer chip (Introduction to the 555 timer) I demonstrated a 555 in an astable oscillator. When I put multipliers in the formulas I got the right answers.

If you don't have a meter or an oscilloscope don't let that stop you. The high frequency oscillator will light both LEDs continuously.

http://www.youtube.com/watch?v=zsxzgNtWLjI

The resistor and capacitor values I show in all these circuits are only starting points. Try different values to see what effect they have on the frequency of the oscillator