555 Timers

EDAboard.com Forum Index -> Hobby Circuits and Small Projects Problems -> 555 Timers

Author

Message

tash_h1

Joined: 14 Feb 2006
Posts: 4

16 Feb 2006 20:16 keygen williamson-labs

Hey, im using an astable oscillator circuit, with a 555 timer, and i want to switch the circuit on for about 2secs, and off for about 4secs. Can anyone help me with what resistor values and capacitor values to use?

Thanks.

ahmad_abdulghany

Joined: 12 Apr 2005
Posts: 1369
Helped: 212
Location: Cairo, Egypt

16 Feb 2006 21:42 Re: 555 Timers

For T_high, you calculate it by making use of caps. (at pins 2 and 6) discharge equations,

And vise versa in case of T_low, where you calculate it from the charging equations of caps at pins 2,6..

I assume that you know how to write such charging and discharging equations,
then, knowing T_high and T_low, you can find easily the time constant of the circuit (time constant = RxC), by proper value of C you then can get R, and this will give square wave output with the required duration (duty cycle = 50%)...

If you need further information, then let me know,
Best Regards,
Ahmad,

philba

Joined: 26 Jan 2006
Posts: 133
Helped: 12

17 Feb 2006 8:08 Re: 555 Timers

you can do it yourself with this 555 calculator http://ourworld.compuserve.com/homepages/Bill_Bowden/555.htm

Have fun
phil

Joaquim

Joined: 22 Jan 2004
Posts: 36

17 Feb 2006 22:29 Re: 555 Timers

Hi
Take a loock also on this wee site http://www.doctronics.co.uk/555.htm#astable).

niket_304

Joined: 21 Dec 2005
Posts: 74

23 Feb 2006 15:17 Re: 555 Timers

try using the datasheet of 555 u will get the formula for the same

fuevarde

Joined: 15 Feb 2006
Posts: 64
Location: San Jose, Costa Rica

26 Feb 2006 19:57 Re: Sotfware 555 Timers

U can find a good software for 555's calcules

the name is 555 designer,

just search in www.google.com

Added after 4 minutes:

I remember i have that soft in my PC...

U can download it!!!

Sorry, but you need login in to view this attachment

tash_h1

Joined: 14 Feb 2006
Posts: 4

27 Feb 2006 15:22 Re: 555 Timers

Thanks to everyone who replied and who helped a great deal!! Very Happy

Cheers!!

fuevarde

Joined: 15 Feb 2006
Posts: 64
Location: San Jose, Costa Rica

27 Feb 2006 21:33 Re: 555 Timers

No problem, I'm glad to help u...

ahmad_abdulghany

Joined: 12 Apr 2005
Posts: 1369
Helped: 212
Location: Cairo, Egypt

28 Feb 2006 0:06 Re: Sotfware 555 Timers

fuevarde wrote:

U can find a good software for 555's calcules

the name is 555 designer,

just search in www.google.com

I remember i have that soft in my PC...

U can download it!!!

Great program !! How did you do it?

Please if you have further similar programs that are used to design anyother applications with other ICs, so upload them here

thanks
Ahmad,

fuevarde

Joined: 15 Feb 2006
Posts: 64
Location: San Jose, Costa Rica

20 Mar 2006 21:42 Re: Sotfware 555 Timers

ahmad_abdulghany wrote:

fuevarde wrote:

U can find a good software for 555's calcules

the name is 555 designer,

just search in www.google.com

I remember i have that soft in my PC...

U can download it!!!

Great program !! How did you do it?

Please if you have further similar programs that are used to design anyother applications with other ICs, so upload them here

thanks
Ahmad,

I have another one for LM555 calculations, but is not free,

and i cant find a keygen or fix in the internet

but u can use a trial version!!!

http://www.schematica.com/555_Timer_design/555_Timer_PRO.htm

I hope u enjoy it!!!

dodo_8008

Joined: 30 May 2006
Posts: 20

12 Jun 2006 20:45 Re: 555 Timers

YOU CAN SEE THIS PAGE:

http://www.proaxis.com/%7eiguanalabs/555kit.htm

IT EXPLAINS THE 555 THEN IT GIVE YOU SOME FORMULA FOR WHAT YOU WANT WITH DRAWING

I TRIED TO USE THOSE FORMULA PRACTICALLY AND IT WAS FULLY SUCCEEDED

ALSO TO HAVE ACCURATE RESULTS YOU HAVE TO CONNECT THE 555 TO +5V NOT MORE OR LESS................TO MAKE 5 VOLT POWER SUPPLY TRY THE FOLOWING LINK:

http://www.proaxis.com/%7eiguanalabs/7805kit.htm

NOTE: THE (LM7805) IN BUILDING THE 5VOLT IN THE PREVIOUS PAGE MUST BE PUT ON HEAT SINKER FOR HIGHT CURRENT
NOTE: YOU CAN HAVE HIGHTER OUTPUT CURRENT BY PUTTING ANOTHER (LM7805) IN PARELLEL

THE DATASHEET OF LM7805:

http://www.ortodoxism.ro/datasheets/fairchild/LM7805.pdf

yogi

Joined: 08 Jan 2005
Posts: 345
Helped: 17

01 Jul 2006 15:55 555 Timers

i think tash_h1 has not understand the circuit of 555 as astable multivibrator. Read this then u will understand better
http://booksbybibin.14.forumer.com/viewtopic.php?t=39

Bibin John
www.bibinjohn.tk

Google
AdSense
Google Adsense

01 Jul 2006 15:55 Ads

jjohn

Joined: 17 Jun 2006
Posts: 275
Helped: 26

01 Jul 2006 15:58 555 Timers

http://www.uoguelph.ca/~antoon/gadgets/555/555.html
http://www.williamson-labs.com/480_555.htm
http://www.doctronics.co.uk/555.htm
http://ourworld.compuserve.com/homepages/Bill_Bowden/555.htm
http://www.national.com/pf/LM/LM555.html