> That duty cycle is going to be hard to achieve with a single 555=20 Maybe a 4001. Two gates as a 1Hz oscillator, two gates as a 10us monostable. Joe --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .