Timing

[Curt Dahlen]

Im building A timer and i want to make 1,-4,5,6min intervals by a switch
to select different resistors, But I'm not sure the right way to figure
out the formula for time, or is this right and its just not that acurate

timing = 1.1 C1 X R1

 

[Costas Vlachos]

"Curt Dahlen" <curtisdahlen@hotmail.com> wrote in message
news:MPG.1a6bf6633c0a1af1989680@news.sk.sympatico.ca...

Im building A timer and i want to make 1,-4,5,6min intervals by a switch
to select different resistors, But I'm not sure the right way to figure
out the formula for time, or is this right and its just not that acurate

timing = 1.1 C1 X R1

You need to provide more information. The formula depends on the type of
timer you're using. If you're using the 555 as a monostable, then the above
formula is correct. Select a C and vary R to get the timings you want. Then
measure with a watch to verify and tweak as necessary.

Costas