time measure

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DexterMccoy

Joined Feb 19, 2014
429
What kind of time measure is T1 and T2?

What are they called?
( It's not the time period or pulse width )

So what kind of circuits would you want to do these types of timings?
 

ronv

Joined Nov 12, 2008
3,768
It is called duty cycle. It is usually expressed as T2 / T1. So your picture would have about a 40% duty cycle.

Duty cycle is often used for PWM and for switching power supplies. Anywhere the ratio of time on to time off is important.
 
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DexterMccoy

Joined Feb 19, 2014
429
but the duty cycle mostly starts/begins/occurs at the leading edge of the high pulse

This time measurement starts/begins/occurs BEFORE the leading edge

the first leading edge of the high pulse/high state has a pre dead signal before the high pulse , what is this called before the High pulse, high state?
 

Thread Starter

DexterMccoy

Joined Feb 19, 2014
429
Not sure

What kind of time measurements is this? depends on what kind of circuit it is

The first pulse has a PRE-trigger delay time it seems

But what kind of circuit would what to measure the time of the pre trigger delay time?
 

ScottWang

Joined Aug 23, 2012
6,777
If they are two signals, then the T2 is the falling edge trigger.

The working situation will be like as:
1. When the system or device started, the T2 will be stop when the falling edge of clock is coming.
2. When the system or device started, the T1 will be stop when the second rising edge of clock is coming.

Designed this was made me a little twisted of my brain, so if any error just point out.

 

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DexterMccoy

Joined Feb 19, 2014
429
How do you know when a circuit is clocked on the falling edge or rising edge? by looking at the schematic? or how do you know? when the clock "occurs" on the negative edge or positive edge?
 

ScottWang

Joined Aug 23, 2012
6,777
From the timing chart, you need to find out the start and stop point, and falling edge, rising edge, and searching the parts which has the function can be satisfy and match the request, experience, searching and reading datasheets, doing the experiment, testing, more and more, and then you will got the idea in your mind.

Checking a lots of circuits and doing a lots of experiments, and then it will give you the spot and light to bring you to the target.
 

Thread Starter

DexterMccoy

Joined Feb 19, 2014
429
Yes true the datasheets will tell if the IC chips are either positive or negative trigger

Without having the datasheets, how would you know if an IC chip is positive or negative trigger?

Why do they have some IC chips that are positive triggered and negative trigger?

what is the advantage of positive trigger compared to negative trigger?
 

ScottWang

Joined Aug 23, 2012
6,777
You can find some more ic symbols has clock as CD4013, 74LS74, etc, and then we can discuss.
 
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