Electronics Forum

Electronics Circuits & Projects discussion forum. Get help with electronics.


Need help please :(

Discuss all your electronics engineering related technical problems and other questions pertaining to design problems in any field of Electrical/Electronics/Computer Hardware

Moderator: pebe

Need help please :(

Postby HanisPF » Mon Sep 02, 2013 10:03 am

Can anybody explain me how does this circuit works ?
Attachments
Capture.PNG
im using this circuit for my project. but i dont know how to explain it :(
Capture.PNG (13.16 KiB) Viewed 15195 times
HanisPF
 
Posts: 1
Joined: Mon Sep 02, 2013 9:55 am

Re: Need help please :(

Postby pebe » Wed Sep 04, 2013 4:21 pm

Both 555s are wired to run as oscillators. There is a connection with no number against it – it is pin2.

With the maximum value of R shown the first 555 runs at 1cycle every 3secs. T=1.4 x .047 x 47 (in megohms and microfarads). The output is a 5Vpp near-triangular waveform at pin6 which varies (with a 15V supply) from 5V to 10V.

That waveform is fed to pin 5 of the second 555 and is used to vary its frequency. With pin5 at 10V the frequency is the normal one calculated as in the first one. F = 1/1.4 x 0.1 x 0.1 = 70Hz. As the voltage on pin5 falls the frequency increases.

So the output from pin3 will be like siren where the frequency goes from 70Hz up to a higher frequency and back down again every 3 secs.

I hope that explains well enough. If not just shout.
pebe
 
Posts: 1058
Joined: Tue Dec 09, 2003 11:12 pm
Location: Ellon, Scotland


Return to EE quiz questions & problems



Who is online

Users browsing this forum: No registered users and 1 guest

Matching pair Intel Xeon X5680 3.33GHz SLBV5 Processor Socket LGA1366 ServerCPU/
$56.21
Matching pair Intel Xeon X5680 3.33GHz SLBV5 Processor Socket LGA1366 ServerCPU/ pictureIntel Xeon E5-2650 V3 CPU Processor 10-Core 2.3GHz SR1YA 25MB 105W LGA 2011-3 /
$114.99
Intel Xeon E5-2650 V3 CPU Processor 10-Core 2.3GHz SR1YA 25MB 105W LGA 2011-3 / pictureIntel Xeon E5-2670V3 SR1XS 2.30GHz 12 Core Socket 2011-3 CPU Processor /
$117.74
Intel Xeon E5-2670V3 SR1XS 2.30GHz 12 Core Socket 2011-3 CPU Processor / pictureIntel Xeon X5460 SLANP Quad-Core Processor Socket LGA 771 3.16 GHz 12M 1333MHz /
$25.16
Intel Xeon X5460 SLANP Quad-Core Processor Socket LGA 771 3.16 GHz 12M 1333MHz / picture


cron