I made a post a long time ago about 555 timers and I considered resurrecting that post as this question is basically the next step along but as the questions are different i thought it'd be tidyer to make a new post.
I'm trying to teach myself about 555 timers and have read through all the basic tutorials I can found. Having done that I created the attached circuit on a breadboard to check I understood what I had read (apologies for the mess, I couldn't rearrange the chip pins on the drawing tool).
I was expecting the LED to flash at a frequency of about 7Hz but what I actually get is a steady on LED. I thought maybe it was just blinking too fast too see so I swapped R2 from a 10k to 100k hoping this would reduce the freq to a little under 1Hz but still a steady on LED.
How I thought this would word - when the output is high C1 would charge and once it hit its threshold voltage the output would switch to low and connect the discharge pin to ground, discharging C1 until it hits the trigger voltage - setting output high, disconnecting discharge pin and charging C1 again.
Since the LED is contestant on that must mean that for some reason either C1 never reaches its threshold or for some reason the chip doesn't realize its reached it?.....right?
Have I done something wrong or missed something?
I'm trying to teach myself about 555 timers and have read through all the basic tutorials I can found. Having done that I created the attached circuit on a breadboard to check I understood what I had read (apologies for the mess, I couldn't rearrange the chip pins on the drawing tool).
I was expecting the LED to flash at a frequency of about 7Hz but what I actually get is a steady on LED. I thought maybe it was just blinking too fast too see so I swapped R2 from a 10k to 100k hoping this would reduce the freq to a little under 1Hz but still a steady on LED.
How I thought this would word - when the output is high C1 would charge and once it hit its threshold voltage the output would switch to low and connect the discharge pin to ground, discharging C1 until it hits the trigger voltage - setting output high, disconnecting discharge pin and charging C1 again.
Since the LED is contestant on that must mean that for some reason either C1 never reaches its threshold or for some reason the chip doesn't realize its reached it?.....right?
Have I done something wrong or missed something?