OD1402 - Lesson 1/Learning Event 1
For more practice, compute the following voltages:
Your answers should be 10, 2, 70, .3, and 6 volts, in that order.
Remember that when the VOLTS/DIV switch setting is in millivolts,
we must convert the millivolts to volts by dividing by 1000.
MEASURING DC LEVELS
To measure the DC level of a waveform, the AC amplitude must be
measured as before. The DC level will be measured by observing the
vertical movement of the top or bottom of the waveform when you
switch the vertical coupling AC/GND/DC switch from the AC to the DC
position. (Refer to figure 12, on the next page.) In this figure,
the AC signal is one volt. The VOLTS/DIV switch is set to .5 and
the AC/GND/DC switch is set to AC. The AC/GND/DC switch is then
set to the DC position. The waveform moves down three centimeters.
Therefore, the DC level of the signal is 1.5 volts. Notice that a
downward deflection is a negative DC level and an upward deflection
is a positive DC level.
The time and frequency of a waveform is always measured along the
horizontal axis of the graduated scale on the face of the CRT.
Therefore, we must calibrate the scope horizontally, just as we
calibrated the scope vertically before making voltage measurements.