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Pulse Train generator waveforms

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dextermccoy

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What are these waveforms called?

They are from a pulse train circuit

The triangle waveform is not a triangle waveform because it's more slanted, so what is the name is this waveform?

it's a slanted triangle waveform? but what is causing the SLANTING ? is it a phase shift?

waveshape#1.jpg
waveshape#2.jpg
 

The triangular waveform looks like parts of an exponentially rising and exponentially falling signal. I am guessing it is the voltage on a capacitor in a series combination of a resistor and capacitor. This shape has nothing to do with a phase shift. I would call it an exponential waveform. Without more information, this is about all that can be said with any certainly.
 

I am guessing it is the voltage on a capacitor in a series combination of a resistor and capacitor. This shape has nothing to do with a phase shift. I would call it an exponential waveform.

yes true

But what's the difference between an Exponential waveform VS a triangle waveform?

Because this exponential waveform looks like a triangle waveshape

Most Exponential waveforms i have seen look like a shark fin , it doesn't look like a triangle waveform

But this one does look like a triangle waveform, any reason why?

What is the other waveform called or about?

The top part of the excusion is exponential or rising

How is this waveform shape made up? it looks like a combination of a squarewaveform with a exponential rising for half of the cycle
 

I do not know of any standard name for the upper waveform. Your description seems good! The bottom waveform looks closer to a triangle wave than the shark fin you mention because the capacitor is partially charged when the voltage starts going up or down. The waveform is only part of a full exponential function. It just appears more linear than a larger segment of the function. In other words, the capacitor is not starting at 0 volts or fully charged but somewhere near the middle. The waveform you see can probably be fit to a portion of the classic RC exponential function. Even though it is only a portion, the waveform is still described as "exponential". A classic use of only a portion of the function is a 555 timer.
 

So what you're saying is that it starts at a fixed bias starting point? To make it be more linear?

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The metal can op amp 741 is old, it outputs a pulse train , but the problem is that it has changed the pulse width and time period compared to a good known board. My question is that how can or why does an op amp change the pulse width or time period from age or what?
 

The waveform only appears or looks more linear. The waveform is a smaller portion of an exponential function. If the period is getting longer, it could be the capacitor which is getting old and has a high leakage current. The op amp may be fine. I would suspect the capacitor first. It is hard to suggest anything without more information on the circuit, such as a schematic diagram.
 

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