A variable frequency sine/triangle wave generator - Page 3 - Electronic Circuits Projects Diagrams Free

audioguru · 28th September 2008, 03:52 AM

Look in Google for Triange Wave Generator Circuit and you will find links that explain all about it.
Look at the datasheet for the uA741 or LM741 and the pins will be explained.

peanutboy · 28th September 2008, 05:15 AM

okay, I hooked it up and nothing is happening, I am getting some sort of sound, a harsh fuzz. doesn't sound like a triangle wave. I still found no advice on what capacitance and resistance to use. what does Rt as opposed to R1 and R2 represent?

audioguru · 28th September 2008, 01:27 PM

An opamp cannot drive a speaker. The oscillator can drive an LM386 power amp that can drive a speaker.
The oscillator cirrcuit uses a dual polarity supply.

The first link in Google has the details of the circuit: http://hobby_elec.piclist.com/e_ckt16.htm It uses a dual opamp so its pin numbers are different than the single 741 opamps.

peanutboy · 28th September 2008, 06:17 PM

I was getting no sound even though I was using powered speakers.
I built according to the non labeled schematic in this thread using two 741s with the + and - pins corresponding to the 741 data sheet.

So... I do however need to be powering a non-powered speaker in the long run. It looks like my best bet is to build an oscillator with an on board amplifier. I have a nice schematic for an lm386 amplifier. perhaps I could just build it right in.

I did not realize how over my head this stuff was going to be when thinking up this project.

I prototyped all of this in software and am attempting to achieve the same results away from a computer in a relatively small package.

argh,

- peanutboy

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28th September 2008, 03:52 AM	(permalink)
audioguru	Look in Google for Triange Wave Generator Circuit and you will find links that explain all about it. Look at the datasheet for the uA741 or LM741 and the pins will be explained. __________________ Uncle $crooge

28th September 2008, 05:15 AM	(permalink)
peanutboy	okay, I hooked it up and nothing is happening, I am getting some sort of sound, a harsh fuzz. doesn't sound like a triangle wave. I still found no advice on what capacitance and resistance to use. what does Rt as opposed to R1 and R2 represent?

28th September 2008, 06:17 PM	(permalink)
peanutboy	building.... I was getting no sound even though I was using powered speakers. I built according to the non labeled schematic in this thread using two 741s with the + and - pins corresponding to the 741 data sheet. So... I do however need to be powering a non-powered speaker in the long run. It looks like my best bet is to build an oscillator with an on board amplifier. I have a nice schematic for an lm386 amplifier. perhaps I could just build it right in. I did not realize how over my head this stuff was going to be when thinking up this project. I prototyped all of this in software and am attempting to achieve the same results away from a computer in a relatively small package. argh, - peanutboy