sine wave to triangle wave

[raviram87]

hello...

i was wondering on converting a sine wave to a triangle wave... The input is a 1khz sine wave and i want to convert it to a triangle wave... my questions are..

(1) my idea is to convert the sine wave to square wave and then convert the square wave to a triangle wave... is this method right? or can we directly convert sine to triangle??

(2) what will be the frequency of the output waveform in any converter? will the output wavefom be periodic with the same frequency as that of the input?

Thanks....

 

[audioguru]

An old 741 opamp converts frequencies above only 9kHz at full output level into triangle waves because of its slew-rate limitation.
An old LM324 or LM358 opamp converts frequencies above only 1kHz at full output level into triangle waves.

Square your sine-waves then integrate the square-waves into triangle waves.

 

[raviram87]

what abt the frequencies? if i want to convert, say my 1khz sine wave into a 300 or 400hz triangle wave.... is that possible?

 

[audioguru]

To change the frequency you could square the sine-wave then use a digital divider to reduce its frequency. Then an integrator will make a sawtooth wave.
3/10ths and 2/5ths are not a symmetrical division so the output will not be symmetrical.

 

[raviram87]

hmmm.... getting it...

am sorry if am annoying the members here... but have few more doubts on this...

if i full wave rectify my sine wave and then give ti to the convereter will i still get a square wave or will it not work cos rectified output is dc?

say for example my sine wave input has a peak to peak amplitude of 8v.. i need a triangle wave that is completely +ve (no -ve cycle)... then can i clip the input waveform and then convert?

 

[audioguru]

A sine-wave, square-wave and triangle-wave are completely symmetrical.
A full-wave rectified sine-wave is not symmetrical so would be difficult to convert into a triangle-wave.

Add an offset voltage to a trangle-wave to make it completely positive.