Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
pop6335 said:How to build 20 minute on , 20 minute off by single 555 timer
A 555 costs 18p or thereabouts and a 16F629 costs 90p as an example. Is your budget really that tight?pop6335 said:Sorry you mean use microcontroller ? , but my project is not using micro controller . is out of the budget.
By the way is we can controller by using the resistor value and cap value ?
pop6335 said:Sorry you mean use microcontroller ? , but my project is not using micro controller . is out of the budget.
By the way is we can controller by using the resistor value and cap value ?
Sceadwian said:Actually the simplest option would be to use the longest stable 555 timer circuit you can find and simply feed the output into a ripple counter IC. Every successive stage will double the effective output'd time. Though since the 555 isn't exactly a precise device you're going to get a lot of variation. If you need 20 minutes exactly (or close to exactly) a micro controller (PIC or AVR) would suit well.