Found this circuit, what can i make out of this?

[Nyklus]

it says opamp function generator
says sine triangle and square wav on the circuit
and also
has a
LM348N ic chip in it.

[artifus]

what can i make out of this?

at least one post consisting of a few pretty pictures posted on diystompboxes.com.

google function generator and follow that trail. read the app notes from ti et al. good luck and have fun.

[Nyklus]

what is ti  et al?

[PRR]

It's a signal-generator for testing your builds.

This one seems to originate at Kitsrus but is better documented at PAiA K23.

[artifus]

what is ti  et al?

ti = texas instruments. they design and make chips and stuff and publish papers about them. other manufacturers do too.

[Thecomedian]

You can find a circuit to turn that triangle wave output into a sine wave output, for starters. Then you can test your pedals putting through different frequency sine waves.

[Nyklus]

oh i just found out that it can only make one frequency

[Thecomedian]

so you'll need a circuit that can turn that frequency into higher or lower frequencies.

[armdnrdy]

oh i just found out that it can only make one frequency

Not sure where you got that info.

In the pictures you posted of the function generator, you'll see a round black thing with an orange cylinder coming out of the center.....This is a potentiometer. This controls the frequency.

You can vary the frequency and wave with a function generator. If it had a fixed frequency it would just be called an oscillator.

[PRR]

> Not sure where you got that info.

I don't think anybody reads anymore, not even words on pictures (it's already GOT a sine).



> You can vary the frequency and wave with a function generator. If it had a fixed frequency it would just be called an oscillator.

Many oscillators vary frequency. The classic Fender tremolo oscillator, the H-P 200AB, the LO in classic radios.

The academic in me is bothered calling this a "function generator", but the useage is widespread.

Oscillators cover a w-i-d-e spread of techniques. The simplest kind have to "build-up". Another kind works with ramps and voltage detectors, always starts-up full level. Either can be vari-freq.

Simple oscillators make near-sines. The sine can be super-good but not perfect.

Ramp-based ocsillators tend to ramp-wave or triangle-wave, with a square-wave at the other side. A true Function Generator can convert the triangle to a Sine. (Here they use diodes to generate a LOG function which is pretty-close to a Sine function and a heap cheaper.)



All this board needs is a battery, an output cap, and possibly an output volume control (it makes Volts of signal and guitars make part-Volts).

[Thecomedian]

heh, prr. you got me, I was 24 hours too tired.

[Nyklus]

can i plug my guitar into it?

[Thecomedian]

it'd be the same as plugging one guitar into another guitar. they both produce voltage waves. There is no "input" for it, so you'd have to figure out how to build one in and keep the circuit working as intended, but why would you want to do this?

[merlinb]

can i plug my guitar into it?

This sounds like a wind up, to me..

[Paul Marossy]

Use it to make a ring modulator?

[Nyklus]

hey paul have any leads on HOW to make this into a ring modulator?

Where would i plug in?

[Paul Marossy]

hey paul have any leads on HOW to make this into a ring modulator?

Where would i plug in?

It would replace the oscillator section of the schematic here: http://experimentalistsanonymous.com/diy/Schematics/Ring%20Modulators%20and%20Frequency%20Shifters/Maestro%20RingMod.gif

Not a simple project though. But true ring modulators are a lot of fun to play with (for me).

[armdnrdy]

hey paul have any leads on HOW to make this into a ring modulator?

Where would i plug in?

It seems as if you are very "Gung Ho" at wanting to mod something. It would be verging on the ridiculous to modify a function generator into a ring modulator when there are plenty of ring modulator projects ready to build.

You seem to be full of ideas for modifications but lack the knowledge to implement them. IMHO you are putting the cart before the horse!
My advise is to build a few pedals first. This will get you acquainted with schematics, data sheets, board layouts, and different components.
This site is loaded full of invaluable information as is the internet. These are great tools.....use them.

A great beginning step to modification is to study similar circuits to see how it can be implemented in the circuit you want to modify. Studying the circuit will help you understand what it is doing which in turn adds another piece of electronics knowledge.

If you just want to come up with ideas and post a thread asking someone else to design the circuit for you won't learn very much.

Once again....My advise is to build a few pedals!

[artifus]

a good get you going read for gung ho noobs: http://loliel.narod.ru/DIY.pdf

[Paul Marossy]

It seems as if you are very "Gung Ho" at wanting to mod something. It would be verging on the ridiculous to modify a function generator into a ring modulator when there are plenty of ring modulator projects ready to build.

Well, not so ridiculous to me. There is one ring modulator that is like a modified Maestro RM out there that uses a bona fide function generator chip for the oscillator section instead of the original arrangement shown on that schematic. But I agree, it's kind of a lot of work to graft it into a circuit like that. Certainly not something for a beginner to even think about. But the question was asked....