Commonly used trigger adjustments

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Commonly used trigger adjustments [Copy link]

The core of triggering is how to set the conditions. This is the most important part of using an oscilloscope, and it is also the part that many users find the most difficult to master. Let's take a look at the commonly used trigger adjustments: Trigger source To make the screen display a stable waveform, it is necessary to add the measured signal itself or a signal that has a certain time relationship with the measured signal to the trigger circuit as the comparison object of the trigger condition. This comparison object is the trigger source. The most common trigger source is the internal trigger (INT), that is, the measured signal is used as the trigger source, such as channel 1, channel 2, and channel 3. When using it, it is important to note that the channel where the signal is currently located is selected as the trigger source. This is a problem that most beginners ignore: using a channel that has no signal connected as the trigger source. In addition to the internal trigger (INT), there are two other trigger sources: external trigger (EXT or AUX IN) and power trigger (LINE). External trigger is a trigger source independent of the signal channel. This trigger source can only be low-frequency and high-frequency signals, and there must be a periodic relationship between the measured signal; power trigger uses the oscilloscope's mains input as a trigger signal. This method is effective when measuring signals related to the frequency of the AC power supply. Interested friends can learn about it by themselves. Trigger level and trigger polarity The trigger level is a voltage value in the oscilloscope display, and the unit is "mV" and "V". In addition, there will be a trigger level line on the interface to indicate its position relative to the signal waveform. The trigger level adjustment of the flat oscilloscope is very simple. Just touch the "Level" line with your finger and move it. Trigger level adjustment is also called synchronization adjustment, which synchronizes the scan with the measured signal. The signal can only be triggered when the trigger level is within the range of the signal amplitude. The trigger polarity switch is used to select the polarity of the trigger signal. When positive is selected, a trigger is generated when the trigger signal exceeds the trigger level in the direction of signal increase. When negative is selected, a trigger is generated when the trigger signal exceeds the trigger level in the direction of signal decrease.