Delay B Sweep Time Base

Thread Starter

watsongrey

Joined Oct 31, 2014
94
The Delay B Sweep Time Base it used to Zoom in and scroll through a waveform
How is the Delay Sweep time base different compared to a Zoom or Magnifying on Digital Oscilloscopes?
I have notice that on Digital Oscilloscopes when magnifying or zooming in on waveforms it will distort them because of the resolution/bandwidth of the digital oscilloscope.
The Delay B sweep time base is mostly used when you have a very high frequency waveforms or a burst of frequencys squished together very tight and small. The Delay sweep time base can expand it out to you can measure the very high frequency.
What have other technicians or you guys used the Delay B sweep time base for?
 

BillB3857

Joined Feb 28, 2009
2,570
Most scopes that have the B Sweep also allow for independent triggering of the B sweep. The trigger is locked out until after the delay.
 

Thread Starter

watsongrey

Joined Oct 31, 2014
94
Most scopes that have the B Sweep also allow for independent triggering of the B sweep. The trigger is locked out until after the delay.

Are you saying that the A sweep can be on Auto mode and the B sweep can be on single sweep mode or use the external trigger?

The scopes do have an independent button for choosing for A sweep and B sweep , Edge polarity with positive or negative
So example: A sweep can be Positive edge triggering
B sweep can be Negative edge triggering

Or what would you use the independent triggering of B sweep for?
 

BillB3857

Joined Feb 28, 2009
2,570
Maybe you need to see an expanded pulse that happens about half way down the sweep of the A sweep but not at a fixed delay from the start of the A sweep. Set the delay to an approximate point that would be before the anticipated pulse in question. Then, the B trigger would be triggered on the pulse in question and the B time base, being faster, would allow you to see details of the pulse which would be seen at the start of the B trace without the need for you to chase it with the delay knob. As you said earlier, if the pulses are predictable as to time spacing, just using the delay of B sweep, without pulse triggering will expand the signal for a more detailed view.
 

Thread Starter

watsongrey

Joined Oct 31, 2014
94
The B sweep just lets you expand or zoom in on pulses from the A sweep. Also the B sweep lets you scroll through all the pulses on A sweep. The B sweep can let you expand/zoom in on Pulses on A sweep so you can view the details and rise time and fall times of pulses on Sweep A. Yes the B sweep is triggered after the Sweep A trigger point.

But I'm still confused as to what would you use the B sweep for? besides expanding/zooming in on the A sweep pulses or waveforms
Old analog Oscilloscopes had a magnify X10 button, so why not just just this instead of using a Delay Sweep B to expand/zoom on a pulse or waveform you can just use the magnify X10 button instead of using a Delay Sweep B?
 

BillB3857

Joined Feb 28, 2009
2,570
Complex waveforms may not have the pulse you want to magnify at a fixed spacing from the master pulses. It is one of the things you may not know you need until you need it. Besides that, maybe you want a magnification factor other than 10.
 

Thread Starter

watsongrey

Joined Oct 31, 2014
94
oh ok thanks
So it's ment for aperiodic waveforms or irregular waveforms or to count how many lines or pulses are in that complex waveform
 
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