Could a 555 timer perform these tasks?

[col32]

Can a 555timer do this?

Gday all,
I was wondering what sort of timing device I would require (the simplest would be preferable). . . also ... the smaller the better

I need some sort of timer or a combination of timers to perform a series of tasks in order.
1. Power one circuit for 10 sec ... then switch off... then
2. Power a second circuit for 2 seconds... then switch off... then
3. Power a third circuit for 5 seconds... then switch off
(the numbers I am using are just arbitary but are around the mark)

What sort of timer could do this? Are there any online tutorials?
Would a 555 timer, or a series of them work?

Any helpful comments would be greatly appreciated!

 

[IanP]

Re: Can a 555timer do this?

A cascade of 555s can do this job ..
See the following post:


Other option is to employ a microcontroller but I am not sure if you would like to follow this path ..

Regards,
IanP

 

[XNOX_Rambo]

Re: Can a 555timer do this?

Cascaded 555:s will do the trick but you can also use a 4017 in this fashion,
which gives you greater flexibility (see the traffic light example):
**broken link removed**

 

[eng_ahmed22]

Re: Can a 555timer do this?

hi
i suggest to use a small microcontroller to do this job like (AT89c2051).
it has an adv. that u can change the time easy becouse it is soft ware controlled.
also it is not expensiv.
but if u build it with hardware, if u want to change any thing u have to chang in the components it self
this is my opinion
hope that usefull for u
salam
Ahmed
www.i-g.org

 

[col32]

Can a 555timer do this?

Thanks very much for the helpful replys. I'm in the process of working out the limitations in a project i'm doing. Cheers.

 

[philba]

Can a 555timer do this?

I have to agree with ahmed. The added flexibility of a uC will allow you to make changes in software rather than changing components. In addition, with a crystal you can get very precise timing.

With a 555, you will need to use 1% components to get any kind of accuracy (the errors multiply) or use multiturn trimmer potentiometers to tune the delays. either approach adds cost and complexity.

Also, if using 555s, I would set it up so you can calibrate each stage seperately.