Triggering Options - Promax OD-514B Instruction Manual

4.3.5 Triggering options

Frequently, triggering selections is the most complicated operation to perform when
using an oscilloscope due to the many options available and the concrete requirements of
some signals.
1.- Triggering Source Selection (SOURCE [26])
The displayed signal itself or a trigger signal which has a time relationship wit the
displayed signal is required to be applied to the trigger circuit to display a stationary signal
on the CRT screen. The SOURCE switch [26] is used for selecting such a triggering
source.
CH1 The internal triggering method which is used most commonly.
CH2 The signal applied to the vertical input terminal is branched off from the
LINE The AC power line frequency signal is used as the triggering signal. This
EXT The sweep is triggered with an external signal applied to the external trigger
The above triggering source signal selection functions are shown collectively in the
following table.
SOURCE/ VERT.MODE
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preamplifier and is fed to the trigger circuit through the VERT MODE switch
[39]. Since the triggering signal is the measured signal itself, a stable
waveform can be readily displayed on the CRT screen. When in the DUAL or
ADD operation, the signal selected by the SOÜRCE switch [26] is used as
the triggering source signal.
method is effective when the measured signal has a relationship with the AC
line frequency, especially for measurements of low level AC noise of audio
equipment, thyristor circuits, etc.
input terminal (EXT [23]). An external signal which has a periodic relationship
with respect to the measured signal is used. Since the measured signal is not
used as the triggering signal, the waveforms can be displayed more
independent than the measured signal.
CH1
Triggered by CH1 signal
CH2 Triggered by CH2 signal
ALT
Alternately triggered by CH1 & CH2
LINE Triggered by LINE signal
EXT Triggered by EXT TRIG input signal
OD-514B, OD-515B & OD-545B INSTRUCTION MANUAL
CH1 CH2
Table 3.-
DUAL ADD
November 2000