More fun with scope image interpretation

[MarkusBass]

Most of the more expensive analog oscilloscopes have a control called Holdoff. This adjusts the time between the end of a horizontal sweep and when the trigger is enabled for the next sweep. If it is adjusted while viewing a 600Hz waveform, a place can be found where the waveform will sync up with the line frequency and the waveform will start wiggling up and down showing the ripple. If the 600Hz is exactly in sync with the line frequency, the wiggling will stop and you will be able to see where each cycle is clipped slightly different.

The scope used here (RIGOL DS1054) has also Holdoff control - this is very good scope. You can select it by selecting MENU button in the TRIGGER section, then select Setting button and the Holdoff control is there. The scope has also the Help button. When pressed it will display detailed explanation of each function. In this case it displays information that the Holdoff knob can change the time when the trigger is re-armed from 16 ns to 10 seconds.

My scope has both variable holdoff and line sync, I guess I never learned how to use either feature to their full advantage!

I'm not sure whether there is anything to learn. You just turn the Holdoff knob and observe what changes it causes on the display.

Mark