triangle
Get flash to fully experience Pearltrees
This circuit is the same as shown above in the Logic Clock but with the supply and LED added. Both IC's can be used and have the same pin connections Cheapo Oscillator Would you believe you can build an oscillator with only three components ? Resistor, capacitor and a NPN transistor .
Handy dandy little circuit #23
duty-cycle can range from 55% to 95% Normally, a 555 can not produce a duty cycle of under about 55%. This is because the timing capacitor C charges up through resistors R1 and R2, but discharges through R2.
555 Timer Calculator
lostinpudy, yes I believe the control input should give you some frequency variability, though I have not looked at it and thought it through to be sure. I'd go ahead and build it if you're a real fan of the 555. However, me, I'd choose the opamp circuit just cause I like opamps. Please do not let the -9V fool you!