How to Generate Sine Waves

[algaeman]

I'm sort of new to electronics, and I would like to know how to generate sine waves. Can I make a simple circuit using capacitors, transistors, etc. or are there inexpensive ICs that make sine waves?

[bodgy]

The answers to your questions are yes to all.<p>You can purchase IC's that are designed to do this try the ICL8038 there are others, you can make a sine wave oscillator with a transistor and a 3 stage ladder phase shift network.<p>wired like

C-C-C -b
r-r- -r<p>Where C are 3 caps in series and R are resistors from the C junction to the Ov line. B is the base of the NPN transistor<p>So the circuit would (starting from the BJT)<p>Connections to the Collector, Resistor from +V to Collector, from juction between collector and resistor an electrolyti cap positive to junction negative is output. also from the junction a conncection to the first C in the above ladder is made. At the Base of the BJT a standard bias divider is used a resistor from +V to base and the bottom resistor is the last resistor in the ladder. From the emitter of the BJT is a resistor bypassed by a highish value electrolytic cap.<p>The freq of osc = f=0.065/(CR).<p>In a ladder circuit the BJT must have a gain of more than 30 and you are stuck with whatever frequency you decide on.<p>There is also a modified multivibrator type circuit and probably the most popular a Wien Bridge<p>almost certainly this site will have what you are looking for
http://users.pandora.be/educypedia/elec ... ubject.htm<p>colin<p>PS You haven't stated what frequency or range of frequency you are looking for. If RF then we really need to bring in inductors or crystals.<p>[ September 06, 2003: Message edited by: bodgy ]</p>

[desterline]

Virgil,
There are lots of ways to skin this cat, and we'd need a LOT more information to even begin to get the "best" one. <p>Since your new to electronics I'd reccomend you find some books and study up. On series I reccomend for begginers is the Engineer's Notebooks by Forrest Mimms. <p>His books are simple and easily understood with many "building blocks" for more complex ideas. His book on Op Amps has a "function generator" that supplies sine waves in the low audio frequencies (a couple kHz).<p>Plus you can get them for $3-$7 at any radio shack. Not that radio shack is the best place, but you can't beat the instant gratification.<p>-Denny

[Chris Smith]

A simple 555 timer pluged into a transformer will produce sine wave out. Perhaps the simplest?

[josmith]

http://www.tinaja.com/magsn01.asp

[algaeman]

Thanks for the help, guys!<p>Bodgy, you kind of lost me there... I have a lot to learn about electronics. I'll look into the ICL8038 you mentioned. I don't really understand the other stuff. And no, I didn't mean radio frequencies, just audible range. The link you provided looks really helpful.<p>Desterline, I'll see if I can get that book you mentioned.<p>Chris: Thanks. That sounds the simplest of them all, and I already have a few 555's (although I don't really understand how to use them yet). I saw another sine wave circuit that uses a 555 timer.