Fnirsi 2C23T Manual página 54

2. Crystal oscillator measurement
When the crystal oscillator encounters capacitance, it is easy to stop
oscillation. The input capacitance of the 1X probe is as high as 100-300pF,
and the 10X gear is around 10-30pF, it is easy to stop oscillation in the 1X
gear, so it needs to be set to the 10X gear, that is, both the probe and
oscilloscope should be switched to the 10X gear (both the probe and
①Firstly, set the oscilloscope to Auto trigger mode (default to Auto trigger mode
after startup), which is used to test periodic signals (crystal oscillator
resonance sine signals belong to periodic signals).
②Set the oscilloscope to 10X gear (default to 1X gear after startup).
③Oscilloscope setting AC coupling mode.
④Insert the probe and pull the switch on the probe handle to the 10X position.
⑤Ensure that the crystal oscillator motherboard is powered on and running.
⑥Connect the probe clamp to the ground wire of the crystal oscillator
motherboard (negative pole of the power supply), pull out the probe cap,
which is the needle tip inside, and make the needle tip contact one of the pins
of the crystal oscillator.
⑦Press the 【 AUTO 】 button once, and the waveform of the tested crystal
oscillator will be displayed. If the waveform after AUTO adjustment is too
small or too large, you can manually adjust the waveform size in zoom mode.
3. PWM signal measurement of MOS transistor or IGBT
The PWM signal voltage for directly driving MOS tubes or IGBTs is generally
within 10V~20V, and the PWM front-end control signal is also generally
within 3-20V. The maximum test voltage for 1X gear is 80V, so using 1X gear
for testing PWM signals is sufficient (both the probe and oscilloscope are set
Gear selection
oscilloscope should be set to the 10X gear)
Gear selection
to 1X gear)
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