Battery or DC voltage measurement
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To measure the DC voltage, we must first ensure that the coupling mode of the channel is in the DC state, like the battery voltage because it is relatively low, the probe attenuation can be 1X than the general, and the vertical gear is set at 1V or 500mv. Then make sure that the trigger mode of the oscilloscope is in automatic state.
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To ensure that the battery is charged or the DC voltage has a voltage output, connect the probe to the battery or the DC positive electrode, and the probe clamp (that is, the ground end) is connected to the battery or the DC negative electrode.
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Of course, the reverse connection has no effect, that is, when the waveform is displayed, it will be below the zero level of the oscilloscope. Open the oscilloscope to measure the average, you can see the DC voltage value.
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Crystal vibration measurement
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Crystal vibration is more sensitive to capacitance load, when the use of ×1 stop, the probe capacitance is relatively large, equivalent to a heavy load in parallel in the crystal circuit, it is easy to make it stop oscillating, so we use 10X probe better.
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We set the oscilloscope channel to AC coupling, 10X gear. After the crystal board is powered on, unplug the probe sleeve to expose the probe. Connect the probe clamp to the mainboard ground wire to supply the negative end, and the probe tip contacts one of the pins of the crystal oscillator.
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Adjust the vertical gear and time base of the oscilloscope so that the waveform is fully displayed on the screen for at least one cycle. In addition, the output edge of the crystal oscillator is generally steeper and the rise time is shorter, because the output of the crystal oscillator contains more high-frequency components, so it should be regarded as a high-frequency signal.
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The bandwidth of the probe ×1 stop is limited, and the probe ×10 stop is full bandwidth open, so the measurement must be performed in the ×10 stop.