### Author Topic: signal  (Read 1140 times)

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#### yyy

• Jr. Member
• Posts: 45
##### signal
« on: September 25, 2009, 02:56:58 AM »
How can I convert square signal to sin signal ?
Also I need that it will fit to wide frequency range
Why in resonance circuit the convert frequency is only for one specific frequency?

#### billhowl

• Supreme Robot
• Posts: 376
##### Re: signal
« Reply #1 on: September 25, 2009, 03:21:55 AM »
It can be done with two stages of integrators, the first one converts the square wave to a triangle wave, and the second stage converts the triangle wave to a sine wave. If the input frequency varies widely then the output amplitude will vary.
Here is a typical schematic, two identical stages are required

A Quick Sine Wave Generator
http://www.national.com/nationaledge/jun04/article.html
« Last Edit: September 25, 2009, 03:30:05 AM by billhowl »

#### Soeren

• Supreme Robot
• Posts: 4,672
##### Re: signal
« Reply #2 on: September 25, 2009, 03:58:52 AM »
Hi,

How can I convert square signal to sin signal ?
Also I need that it will fit to wide frequency range

How wide?

Can be done in several ways - a PLL controlling a DDS Sine generator would be my choice.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Engineering is based on numbers - not adjectives

#### yyy

• Jr. Member
• Posts: 45
##### Re: signal
« Reply #3 on: September 28, 2009, 07:15:41 AM »
Thanks billhowl & soeren
Soeren, what do you main in PLL controlling ?
Can you explain it ?

#### Soeren

• Supreme Robot
• Posts: 4,672
##### Re: signal
« Reply #4 on: September 28, 2009, 09:38:27 AM »
Hi,

Soeren, what do you main in PLL controlling ?
Can you explain it ?
PLL = Phase Locked Loop.
DDS = Direct Digital Synthesis

The PLL looks at both the output from the DDS and your square wave signal and "locks" the two together.
If the signal drifts/deviates, the PLL will correct it,
The output from a DDS can be anything you can imagine, sine, triangle, saw tooth or something entirely different, like the quack of a duck

What's your purpose with the converted signal?
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?