ChrisPDuck
New Member
Ok i am Making a simple 555 timer circuit on a breadboard using the astable circuit diagram.
R1 is 1Kohm
R2 is 10kohm
C is 470 microfarad
According to my maths this should give me an on time of about 3~ seconds and then an off time of about the same.
BUT, for some reason the LED will just stay lit.
I've put a multimeter across the capacitor, and it will charge up to about 7.5v ( off a 7.8v supply) and then stay charged.
Can anyone help? i'm kinda getting annoyed with it now lol
Thnx
Duck
R1 is 1Kohm
R2 is 10kohm
C is 470 microfarad
According to my maths this should give me an on time of about 3~ seconds and then an off time of about the same.
BUT, for some reason the LED will just stay lit.
I've put a multimeter across the capacitor, and it will charge up to about 7.5v ( off a 7.8v supply) and then stay charged.
Can anyone help? i'm kinda getting annoyed with it now lol
Thnx
Duck