PAG 5.3 - Measuring frequency and amplitude using an oscilloscope Flashcards
What does an oscilloscope trace look like for a DC supply?
When the time base is turned on, direct currents produce a horizontal straight line at the level of the supply voltage
If the time-base is switched off, what will the oscilloscope trace look like for a DC supply?
A single dot will be shown at the height of the supply voltage
What will an oscilloscope trace look like for an AC supply?
sinusoidal waveform being displayed on the oscilloscope screen. This is because of the polarity of the supply is continually oscillating with time
If the time-base is switched off, what will the oscilloscope trace look like for a AC supply?
Straight vertical line formed
How can you increase the number of complete wavelengths that are visible on the oscilloscope screen?
Time-base can be adjusted so that the increments can be larger. This will result in more wavelengths being visible.
What should you adjust if the maximum voltage isn’t visible on the oscilloscope screen?
Volts per division can be increased, higher voltages become visible.
How can the time period of an AC supply be determined from an oscilloscope trace?
Measure distance from same point on two adjacent waves, and then compare to the time based to scale it to produce the time period
How can the frequency of an AC supply be calculated from its time period?
Inverse of time period
How can the peak to peak voltage be determined from an oscilloscope trace?
Measuring the distance from the peak to trough, twice the amplitude
What is the amplitude of a waveform?
Maximum displacement from a wave’s equilibrium position
How should the oscilloscope be scaled to measure a voltage with the greatest accuracy possible?
Volts per division should be adjusted so that the waveform fills the screen, without max voltage exceeding the scale
