Multimeter AC voltage measurement circuit

To measure the converter voltage, you can set the right transfer switch and the left range selection switch to any AC voltage level. At this time, the measurement circuit
is composed as shown in the figure.
    At this time, the shunt resistor connected in parallel with the meter is still
the same as the DC voltage range, but another 2. 25kfl resistor is connected in series. Then use
a 3.8kn resistor to shunt the meter so that the sensitivity of the meter
is lower than when measuring DC voltage.
  This meter uses a half-wave rectifier circuit with low rectification efficiency. However, because
the additional resistance is shared with the additional resistance of the DC voltage, for example,
the additional resistance of the AC 250V range is exactly the additional
resistance of the 50V DC voltage range, and the difference between the two is up to 5 times. It can be seen that the voltage sensitivity of the AC voltage range
is one-fifth of the DC voltage.
    2000fl/V÷5=4000/V
    This is to reduce the additional resistance to compensate for
the decrease in meter current due to low rectification efficiency. Make sure that the scales of AC voltage and DC
voltage are basically the same.
    To measure 2500V AC high voltage, use the specially equipped 1OMfl additional resistor. The high voltage to be measured is connected between the two jacks "2500V and "*", and the range
switch can be placed in any range from 10 to 500V.
    In addition, a 10F electrolytic capacitor is connected in parallel to the outer terminal to smooth the rectified pulsating voltage, so that the multimeter When measuring low frequencies below 10Hz, the pointer
will not shake.