# Square to Triangle Wave Integrator Amplitude Problem

#### Tony Elliott

Joined May 8, 2015
155
So, I understand that you use electrically conductive paint and longer traces have more resistance and that resistance change alters the frequency of the 555 timer.

Is that correct?
yes thats exactly right

#### GS3

Joined Sep 21, 2007
408
So much secret makes hard to understand anything.
I agree. In some threads getting information from the person looking for help is like pulling teeth: a slow and painful process. We're whistling in the dark here.

Since we don't know the exact requirements it is very difficult to help. If it does not have to be exactly triangular but an approximation would do then you already have it at the 555 timing capacitor, and with constant amplitude already.

#### Tony Elliott

Joined May 8, 2015
155

Here are the schematics of the circuits I have built. apologies, I should have posted these sooner.

#### Tony Elliott

Joined May 8, 2015
155
The triangle circuits capacitor I have changed to a 1uf to create a better shape at low frequencies as it tended to curve to the right

#### GS3

Joined Sep 21, 2007
408
The op-amp does not give you a true triangular wave but an exponential ramp which you already pretty much have at the 555 generating the original square wave. Of course, with a separate device you have more control over amplitude etc. That why I asked if it had to be a true triangle with straight ramps.

#### Tony Elliott

Joined May 8, 2015
155
Ah I see, do you think I should find a different triangle integrator? and a
Automatic Gain Control PreAmplifier?

#### Tony Elliott

Joined May 8, 2015
155
http://www.theremin.us/Circuit_Library/converter.htm

I found this schematic and it says "This circuit converts a square waveform to a triangle waveform while automatically maintaining a constant triangle amplitude for a wide range of input frequencies. Although originally designed for application in a communications system, the idea is readily adaptable for certain electronic music applications where waveform conversion is desired".

do you feel this will work with my square wave 555/4013 circuit?

#### GopherT

Joined Nov 23, 2012
8,012
The op-amp does not give you a true triangular wave but an exponential ramp which you already pretty much have at the 555 generating the original square wave. Of course, with a separate device you have more control over amplitude etc. That why I asked if it had to be a true triangle with straight ramps.
If he removes the 100k feedback resistor, he should have a linear ramp (up and down). A constant current into a capacitor gives a linear ramp for his triangle.