555 timer ic

techintraining

I am doing a project in college, we built this signal generator and are doing a write up.

Can anybody tell me what the function of the 555 timer ic is in this?

Below is the signal generator we built.
http://www.vellemanusa.com/products/view/?country=us&lang=enu&id=350680

CreepingDeath

techintraining wrote: »

I am doing a project in college, we built this signal generator and are doing a write up.

Can anybody tell me what the function of the 555 timer ic is in this?

Below is the signal generator we built.
http://www.vellemanusa.com/products/view/?country=us&lang=enu&id=350680

I'm not sure if that's better suited to the Electrics forum ?

I've only briefly read a beginners book on electronics before and think the 555 timer can be programmed to trigger a signal/switch every X milliseconds.

For a signal generator that would probably control the frequency of the signal.
So if it was set to turn on an output pin 20,000 times a second and you wired it to a speaker, the speaker would emit a sound at 20khz

dilallio

Have a look at http://en.wikipedia.org/wiki/555_timer_IC

The 555 in your signal generator will be functioning in astable mode, and basically outputs a low voltage continuous stream of rectangular pulses at a frequency set by the resistor (x2) and capacitor(x1) values.

In your signal generator, one of these resisters will be a variable resistor which will increase / decrease the frequency of the pulse.

The signal generator will also contain an amplifier which will increase / decrease the amplitude of the pulse.

It probably also has one or more filters to adjust the shape of the pulse.

techintraining

Cheers :-)

ZENER

Along with the humble 741, the 555 is probably the most useful IC around from an analogue point of view. Always have a few of them in my components drawers.

Ken