I was hoping someone could help me understand a very simple approach to creating a flashing led. While many simple examples exist, I cant quite find one that allows me to control both the pause rate and display duration times.. for example: led on (emitting) "10ms" led off "30ms" (repeat forever). Or perhaps I swap out a capacitor to creat "led on 500ms" led off "2ms" (repeat forever). Anyhow, I have capacitors to work with, 555 times, resistors, diodes. I'm a real beginner obviously, and do not know how to design around the 555 - but if someone has a very easy suggestion I can attempt I'd appreciate it. I'm attempting to study the effect of "charging" a glow in the dark object with a 3.3v UV Led and thought it would be neat to see the minimal amount of strobing required to energize the glow. Thanks!
Just Googling "555 astable circuit" will list plenty of web sites. This one: 555 Oscillator Tutorial gives the equations for the on time and off time.