Tektronix TDS1000B Series Operator's Manual page 21

1
Introduction to Oscilloscopes and Probes
A positive voltage causes the dot to move up while a
negative voltage causes the dot to move down. The signal
also travels to a trigger system, which initiates a horizontal
sweep. The trigger causes the time base on the X-axis of
the display grid to move the glowing dot from left to right
across the screen within a specified time interval. When
many sweeps occur in a rapid sequence, the movements of
the glowing dot blend into a solid line. Together, the
horizontal sweeping and vertical deflecting actions are
displayed as a signal graph on the screen.
You use triggering to stabilize a repeating signal. Proper
triggering ensures that the sweep begins at the same point
of a repeating signal so that a stable waveform is visible.
Figure 1.4 shows untriggered and triggered waveforms.
Figure 1.4: Untriggered and triggered display
TDS1000B and TDS2000B Series Oscilloscopes – Operator Training Kit 1-7