Example of Ripple In A DC Signal


  • The example display view we see on the left is a 10V D.C. signal. When we view it with the CRO in D.C. mode we must view on a minimum scale of 2V/div in order to view the signal on the display If the scale was turned to 1V/div the line would not be visible. (to learn more about the vertical gain/scale adjustment click here.)
  • Now when we view the signal in this mode it seems that we have a perfect D.C. signal. But we do know from the example heading that this signal has a 10mV A.C ripple. So we use the method shown below to investigate this.

  • The example display view we see on the left is a 10V D.C. signal. But this time it is viewed with the CRO in A.C. mode; the D.C. component of the signal is not visible on the display so the scale can be set at a much lower value, In this case it was set to 5mV (to learn more about the vertical gain/scale adjustment click here.)
  • Now when we view the signal with the CRO in this configuration we see that the signal is not perfect and actually has a ripple of 20mV A.C.
  • This shows us that D.C. signals are not always what they seem.


Page maintained by EIE WebMistress
Revised:
15 September 2004