In "Talking about the Trigger Modes and Functions of Analog Oscilloscopes", we learned a lot about the trigger modes of analog oscilloscopes. In this article, we will learn about the trigger sources of oscilloscopes and the functions of triggers.
Triggering is when using an oscilloscope. In order to synchronize the scanning signal with the measured signal, we can set some conditions, and constantly compare the measured signal with these conditions, and start scanning only when the measured signal meets these conditions. Make the scanning frequency the same as the measured signal or have an integer multiple relationship, that is, synchronization. These conditions are the trigger conditions. For example, the ZDS2024Plus oscilloscope is equipped with 22 protocol triggers. You can set the trigger mode according to my needs.
The purpose of triggering is to start at the same position of the waveform every time it is displayed, so that the waveform can be displayed stably. Generally, analog oscilloscopes have edge trigger, video trigger and mains trigger. On digital oscilloscopes, there are more trigger conditions called advanced triggers such as logic trigger, glitch trigger and pulse width trigger.
The role of triggerWhen a signal is introduced into the oscilloscope, if the display of the signal is not controlled accordingly, the display will be messy, and the display on each screen is different. When the oscilloscope is refreshed quickly, the signal we see is aliased. Without a stable image, it is impossible to observe and measure. In order to solve this situation, we need to specify the trigger conditions of the oscilloscope to achieve stable synchronization and display the signal clearly
About the origin of the trigger modeIt is almost always necessary to trigger the oscilloscope, but not necessarily on the displayed signal. Sources commonly used to trigger a scan include:
Signal entering any input channel
External sources other than the signal applied to the input channel
"Power frequency" power signal display
The signal calculated from the evaluation results of one or more inputs inside the wave device
Most of the time, you can set the oscilloscope to trigger on the displayed channel. However, the instrument can trigger on any channel input, regardless of whether it is displayed or not; it can also trigger from a source connected to a dedicated trigger input. Most Tektronix oscilloscopes also provide a discrete output to provide a trigger signal for another instrument, such as a counter, signal source, and so on.
Trigger source selectionIf a stable waveform is displayed on the screen, you need to add the measured signal itself or a trigger signal that has a certain time relationship with the measured signal to the trigger circuit. The trigger source selection determines where the signal is supplied. There are usually three trigger sources: internal trigger (INT), power trigger (LINT), and external trigger (EXT). The internal trigger uses the measured signal as the trigger signal, which is a frequently used trigger method. Since the trigger signal itself is a part of the measured signal, a very stable waveform can be displayed on the screen. Either channel 1 or channel 2 in the dual trace oscilloscope can be selected as the trigger signal.
Power trigger uses AC power frequency signal as trigger signal. This method is effective when measuring signals related to AC power frequency. Especially it is more effective to measure the low-level AC noise of audio circuits and thyratrons. The external trigger uses an external signal as the trigger signal, and the external signal is input from the trigger input terminal. There should be a periodic relationship between the external trigger signal and the measured signal. Since the signal under test is not used as a trigger signal, when to start scanning has nothing to do with the signal under test. The correct selection of the trigger signal has a lot to do with the stability and clarity of the waveform display. For example, in the measurement of digital circuits, for a simple periodic signal, it may be better to choose an internal trigger, but for a signal with a responsible period and a signal with a period relationship with it, it may be better to choose an external trigger. Great.
Hp Pavilion Gaming 15-Cx,Hp Pavilion Gaming 15-Cx Lcd Back Cover,Lcd Back Cover,Hp Pavilion Laptop Replacement Parts
S-yuan Electronic Technology Limited , https://www.syuanelectronic.com