need analog cosine circuit

[ahmed_elsayed00]

Please help me :
I need an analog circuit which gives an output voltage equal to the cosine of the input voltage. output voltage=cos input voltage.
Thanks

 

[Analog]

Please help me :
I need an analog circuit which gives an output voltage equal to the cosine of the input voltage. output voltage=cos input voltage.
Thanks

You need to post some intelligent parameters whenever you post something like this here. What levels of input voltage? What levels of output voltage? What range of frequency? What are the power supplies required?

Please do some thinking before posting here.

 

[ahmed_elsayed00]

Thank you Analog for your interest.
First I want to know if any boady has an idea to do this circuit or not.
the input voltage is DC from 0mv to 90mv.
the power supply is 10 votage DC
the output votage is DC from 0v minimum to 200mv maximum.
Let us see thinking!

 

[eng1]

A look-up table (PIC-based circuit)?

EDIT: ops... you need an analog circuit!

 

[eng1]

A VCO with diodes shaping the output?

 

[Analog]

**broken link removed**

 

[Hero999]

This isn't college work is it?

If so do it yourself.

 

[ljcox]

Please help me :
I need an analog circuit which gives an output voltage equal to the cosine of the input voltage. output voltage=cos input voltage.
Thanks

Since cos x = -Int (sin x dt) and cos x = d(sin x)/dt

then either an integrator or differentiator circuit would do it.

However, if you use the integrator, then you will need a amplifier (before or after the integrator) with a gain of -1 to correct the sign.

 

[Roff]

Since cos x = -Int (sin x dt) and cos x = d(sin x)/dt

then either an integrator or differentiator circuit would do it.

However, if you use the integrator, then you will need a amplifier (before or after the integrator) with a gain of -1 to correct the sign.

Len, if you think of it in the time domain, I think he would be converting a ramp to the first 90 degrees of a cosine. I don't think he's starting with a sine wave and wanting to shift the phase 90 degrees. In the general case, the input is the phase, the output is the cosine of the phase.

 

[Hero999]

Possibly for converting a triangle wave to a sinewave?

 

[Roff]

Possibly for converting a triangle wave to a sinewave?

It will only work if the amplitude of the triangle wave is exactly right. This is seen, of course, in analog function generators.

 

[ahmed_elsayed00]

In fact I need this circuit to calculate the adjacent to the angle

I have 2 linear signals v1 which determine the length of the hypotenuse

v2 determine the angle

and so I need an analog circuit gives a linear output voltage=v1cosv2

The circuit which suggasted by Analog in the following link:

**broken link removed**

do this function but I didn't find th MPY634 in our country , .. I will order it to try this circuit..

also I search for another circuit to be more economic.