Making a sine wave generator using my Arduino Uno. Building a Chebyshef Low Pass. Came across this schematic for it. What is the component at the right side labeled 100K?
Thanks!
100K Ohm potentiometer, probably for output level control (volume).
aharasewych:
What is the component at the right side labeled 100K?
A potentiometer, setting output amplitude. Note that the response of the filter varies by load, so it's built with a low impedance load, and then provides a high impedance output. A better isolation would be an op amp, but if you're adding that, you might as well be building an active filter with steeper cut-off.
Btw, if that's an anti-aliasing / reconstruction filter for something like a square wave input, a 12 kHz corner frequency means a 24 kHz overtone will only be at -15 dB below unity. It won't be close to a real sine wave.
Yes it is a very poor filter design.
Is the sin wave frequency fixed?
If not it will not be a good sin wave at lower frequencies.
Well, found a lab for it online and this is how they had it pictured. So long as i can get a sun wave to show up, ill be fine - doesn't have to be perfect.
http://interface.khm.de/index.php/lab/experiments/arduino-dds-sinewave-generator/
More about learning how it works. but thank you. However, if you know of another method/filter that can be put together quickly and frugally, let me know!
So long as i can get a sun wave to show up
I think you mean Sin.
More about learning how it works
OK fine, as long as you remember it will give you a very low output signal, and just like that link not very much of a Sin wave.
Hmm... The two 270 ohms resistors... they make me feel unconfortable. A bit low and using an Arduino output to them. That is the part that I am not comfortable with.
Did you have a simulator you can use ? It may help you.