looking for a signal generator
 

hi all ,
i m looking for a simple sine wave generator w freq range control ( around 40 to 150 hz ) a pulse function w control ( around .1 sec to 5 sec ) ... any idea ?

Hi Ahmad_tbp,
Try to find an old B&K 3020 or similar. It's not the cleanest sinewave, but you are looking for a function generator.

If you need a better sine wave, any oscillator will work, build a gate controller by another circuit (555 timer) for your burst controller.

-Chris

hi anatech , and thanx for reply
i never worked with a generator before or never build one , i know nothing bout them , i wanna build one ( as u said a function generatr ) for a friend of mine , so do u have any schematic , article or any thing that can help me plz ? :)

Do you have a sound card on your computer? If so, you've got yourself a sine wave generator.

Hi SY,
Standard warnings about grounds and output circuit protection apply! ;)

-Chris

hi sy , yeah i have a sound card !!! ( one of the best old ones!! ) , and already have a very usefull tone generator software with all i need , as i said ,one friends of mine saw this software and ask me if i can build a circuit , doin like this software , so i wanna build him one ! lol :D
i found this circuit : http://www.electronickits.com/kit/co...meas/ck102.pdf
, how is it ? and how can i change the freq in this circuit ?
and one thing else , any idea how to give this circuit a pulse generator control ???

Hi Ahmad_tbp,
The resistor, R5 varies the frequency. Your output sine wave will be poor with that circuit.

Why not use the XR2206 there are many links for it, as well as the data sheet. Or you can use the XR8038 that does the same thing. It's all in a chip for you and better than was the link you posted will give in performance.

-Chris

TureAudio's freeware version will give you a sine-wave generator.

In fact, if you have access to some opamps and a '555 timer (NE555 or LM555) you can make a pulse generator or sinewave generator. Search "NE555 Circuits" or "555 Circuits Mims" on google.

To get a good sinewave out of an NE555 you have to take a pair of opamps and configure as a 4th order low-pass filter after the output pin (3) of the NE555.

Hi jackinnj,
The only problem with that approach I can see is that it has to be a tracking filter for variable frequencies out. Output level instability may result.

A tuneable wien bridge may work, but the one chip wonders seem to address the problem directly. You can gate the output on and off with a 555 type squarewave oscillator. This statisfies all the requirements.

-Chris

Dazyweb is back, too. Their sig generator software is very versatile.