need help please

[ranon]

please,,any one can help me?? i need a speed switching circuit by using 555 that generate a variable square wave,,any one can help me by this circuit

 

[carbonzit]

For one thing, you'd do a lot better by giving your post a more descriptive title than just "I need help". Help with what? Some folks won't look at a thread unless it's on a subject they're interested in.

You should also be more specific about what your circuit application is, as there are tons and tons of questions here about using 555s to generate timing signals.

 

[ranon]

iam sorry but this is my first time to deal with this site and i don't know how can i ask a question ok can u help me in this,,,i have a project on (canary door bell ) and by details i said first,,,note; iam egyption so i am not good in english,,thnx for your advice

 

[carbonzit]

Details? What details?

How about frequency? duration? voltage? current? Those are details.

 

[ranon]

i need low frequency square wave output may be done by 555 timer, and a smale voltade in range 5v to 12v ,variable duty cucle so variable frequency and i don't have any information about current

 

[SABorn]

Need help please..........Prompts me to tell you to call a doctor!!!

As for your 555 circuit do a google search on...... Monostable 555 timer circuits

You will find 100's of designs all very similar and information on how to change the design to suit your needs.

It is a very basic circuit design and basic electronics to construct.

Pete.