How to make a triangle wave "on paper"?

Thread Starter

paultwang

Joined Mar 8, 2006
80
I need to simulate a circuit using OrCAD. The problem is I don't have a triangle wave voltage source. All components are ideal so generators based on noise oscillation do not work. Please recommend a method to generate triangle wave at specified frequency.
 

Papabravo

Joined Feb 24, 2006
13,691
Originally posted by paultwang@Apr 19 2006, 11:41 PM
I need to simulate a circuit using OrCAD. The problem is I don't have a triangle wave voltage source. All components are ideal so generators based on noise oscillation do not work. Please recommend a method to generate triangle wave at specified frequency.
[post=16348]Quoted post[/post]​
In the real world:
What is the integral of a step function? A ramp!
What is the integral of a negative step function? A negative ramp!
Put a positive step and a negative step together and you have a square wave.
Integrate the squarewave and you'll get a triangle wave, almost certainly.

In the simulated world:
You can specify a pulse generator with a very long rise time and a very long fall time and a frequency such that the rise time is half the period and the fall time is half the period, and behold the magical mystical TRIANGLE wave.

Very clever these simulators.
 

Mazaag

Joined Oct 23, 2004
255
Originally posted by paultwang@Apr 19 2006, 10:41 PM
I need to simulate a circuit using OrCAD. The problem is I don't have a triangle wave voltage source. All components are ideal so generators based on noise oscillation do not work. Please recommend a method to generate triangle wave at specified frequency.
[post=16348]Quoted post[/post]​
I was thinking maybe you could make a square wave relaxation oscillator, then feed it into an integrator. Yes I know the opamp requires noise to start of.. what you could do is put a voltage source with a very small value (say micro volts) into the non-inverting terminal. That will give you the intial rail voltage required to start up the relaxation oscillator...

Papa please tell me if anything I said up there makes sense :p....

paul don't read anything I said up there till Papa says its okay to.. :p
 

Papabravo

Joined Feb 24, 2006
13,691
Originally posted by Mazaag@Apr 21 2006, 02:39 PM
I was thinking maybe you could make a square wave relaxation oscillator, then feed it into an integrator. Yes I know the opamp requires noise to start of.. what you could do is put a voltage source with a very small value (say micro volts) into the non-inverting terminal. That will give you the intial rail voltage required to start up the relaxation oscillator...

Papa please tell me if anything I said up there makes sense :p....

paul don't read anything I said up there till Papa says its okay to.. :p
[post=16386]Quoted post[/post]​
Fine by me
 
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