e_neophyte
New Member
I'm REALLY new at this so go easy! I've just breadboarded a simple circuit that uses a 555 timer to clock a 4017 counter and light a series of 10 leds in sequence. (I'm just doing this to learn how these circuits work.)
The circuit works fine except for one thing: When I turn the power on, output 2 (pin 2) lights up first followed by outputs 3, 4, 5, 6, 7, 8, 9, 10. The second sequence then starts properly with output 1 (pin 3) followed by outputs 2, 3, 4, 5, 6, 7, 8, 9, and 10.
In other words, output 1 is skipped the first cycle but each subsequent cycle works correctly.
Why does this happen? My input pins are each grounded (no floating inputs). The correct leds are connected to the correct pins (according to two different pinout sheets that I've consulted). What am I doing wrong?
As an aside, if I hook up output 1 AS THOUGH IT WERE OUTPUT 10, the leds fire in the desired order but ACCORDING TO THE PINOUT, they are firing as 2, 3, 4, 5, 6, 7, 8, 9, 10, 1.
Any help appreciated!
The circuit works fine except for one thing: When I turn the power on, output 2 (pin 2) lights up first followed by outputs 3, 4, 5, 6, 7, 8, 9, 10. The second sequence then starts properly with output 1 (pin 3) followed by outputs 2, 3, 4, 5, 6, 7, 8, 9, and 10.
In other words, output 1 is skipped the first cycle but each subsequent cycle works correctly.
Why does this happen? My input pins are each grounded (no floating inputs). The correct leds are connected to the correct pins (according to two different pinout sheets that I've consulted). What am I doing wrong?
As an aside, if I hook up output 1 AS THOUGH IT WERE OUTPUT 10, the leds fire in the desired order but ACCORDING TO THE PINOUT, they are firing as 2, 3, 4, 5, 6, 7, 8, 9, 10, 1.
Any help appreciated!