SparkFun Forums

[deathrow721]

Is there anyway possible i could mae one of these with only 3v instead of 5v?

ill be makin 1 with 2-500ohm resistors and a 33uf capacitor

thanks

[leon_heller]

What sort of astable?

Leon

[deathrow721]

this http://www.kpsec.freeuk.com/images/555ast.gif

with 2 aa batteries 500ohm resistors and a 33uf capacitor and a 555 timer

[leon_heller]

I think the 555 works down to 3V. Check the data sheet. If not, you could use the CMOS version.

Leon

[deathrow721]

ight thanks yea it seems like the ne555p that i had starts at 5v but knowing that cmos timers start at 2v will come very usefull.

Just one more question...Will i get the same output "pulse" that i would have if i were using all the same parts i mentioned and the 5v it needed...... instead of 3v that i will be using with the new cmos 555 timer that ill be getting

sorry let me know if this question does not make sence and ill try to re phrase it

[deathrow721]

here..ill try to make the question easier anyway

Design 1 = http://www.kpsec.freeuk.com/images/555ast.gif
regular 5v 555 timer
500ohm resistor
500ohm resisor
33uf capacity
and uses 5volts of energy

Design 2 = http://www.kpsec.freeuk.com/images/555ast.gif
cmos 2v low 555 timer
500ohm resistor
500ohm resistor
33uf capacitor
and use 2AA batters so 3v i guess

note the cmos has a 2v low and will be using 3volts. (im not sure if anything special needs to be done)

basically im just wondering if the pulse speed of design 2 will be the same as design 1.......And also just checking that when u make an astable with a cmos chip you use the same configuration as you normally would
thanks again for the help

[leon_heller]

Details of the calculations you need should be in the data sheets.

Leon