Electrical Engineering! Why can not directly use a multimeter to measure the power supply of the exchange of ripple?
In general, multimeter AC can only measure the pure AC voltage. The output voltage of the regulated power supply is equivalent to the DC voltage + ripple voltage, and the multimeter exchange file can not be measured normally.
In addition, the ripple voltage is not necessarily a sine wave voltage, the regulated power supply itself or by external interference will produce complex ripple voltage, and the general multimeter AC voltage file is measured the average AC voltage. The ripple voltage is not a pure sine wave when the multimeter can not be accurately measured.
From the other side, the general linear power supply can only guarantee the output voltage in the lower frequency range of stability, and for more than tens of kHz ripple rejection is very limited. That is, the ripple voltage frequency is generally higher, may have exceeded the multimeter AC file frequency response range, this time the multimeter is still unable to correctly measure.
Since you said the ripple, naturally is a slight fluctuations.
Multimeter is generally used to measure the relatively large value of the parameters, to measure the ripple that can only use oscilloscopes such as precision instruments to complete.
Interested in understanding the power regulator circuit section, as well as a variety of multimeter principle, the use of oscilloscope.
In general, multimeter AC can only measure the pure AC voltage. The output voltage of the regulated power supply is equivalent to the DC voltage + ripple voltage, and the multimeter exchange file can not be measured normally
In addition, the ripple voltage is not necessarily a sine wave voltage, the regulated power supply itself or by external interference will produce complex ripple voltage, and the general multimeter AC voltage file is measured the average AC voltage. The ripple voltage is not a pure sine wave when the multimeter can not be accurately measured
From the other side, the general linear power supply can only guarantee the output voltage in the lower frequency range of stability, and for more than tens of kHz ripple rejection is very limited. That is ripple voltage frequency is generally high, may have exceeded the multimeter AC file frequency response range, this time the multimeter is still unable to correctly measure
