Polygamy capacitor quality testing methods
Author: Shenzhen Yuan Zhi Electronics Co., Ltd.Time:2018-03-01 17:15:30Views:1731【SML】
A
capacitor with good performance at the moment of power on, the
multimeter\'s needles should have a larger swing; the greater the
capacity of the capacitor, the greater the swing of the watch hands...
label:
A
capacitor with good performance at the moment of power on, the
multimeter's needles should have a larger swing; the greater the
capacity of the capacitor, the greater the swing of the watch hands,
swinging, the watch hands can gradually return to zero. If
the capacitor in the power of the moment, the multimeter pointer does
not swing, then the capacitor failure or open circuit; if the needles
have been indicating the power supply voltage without swinging,
indicating that the capacitor has been punctured short circuit; if the
needle swing normal, but does not return to zero , Indicating that the capacitor leakage phenomenon, the higher
the indicated voltage value, indicating that the greater the leakage.
It
should be pointed out that the auxiliary DC voltage used for the
capacitor with small measuring capacity can not exceed the withstand
voltage of the capacitor under test to avoid breakdown of the capacitor
due to the measurement. To accurately measure the capacity of the capacitor, you need to use a capacitive bridge or Q meter. The above simple test method, only a rough judge of gauge capacitor is good or bad.
1, check with a multimeter resistance file electrolytic capacitor is good or bad
Electrolytic
capacitor of the two leads have positive and negative points in the
check of its good or bad, the lower voltage electrolytic capacitors (6V
or l0V), the resistance file should be placed R × 100 or R × 1K file,
the Red
pen connected to the negative terminal of the capacitor, black pen
connected to the positive end, then the multimeter pointer will swing,
and then restored to zero or zero near. Such electrolytic capacitors are good. The larger the capacity of the electrolytic capacitor, the longer the charging time, the slower the pointer swings.
2, with a multimeter to determine the positive and negative lead electrolytic capacitors
Some
electrolytic capacitors with lower withstand voltage, if the positive
and negative lead marks are unclear, can be judged according to its
positive connection when the leakage current is small (large resistance
value) and the reverse leakage current is large. The
specific method is: contact with the red and black pens of the two
leads of the capacitor, remember the size of the leakage current
(resistance) (pointer swing back and stop when the indicated
resistance), and then the capacitor positive and negative leads short Then, the red, black test leads and then measure the leakage current. Judging
by the indication of small leakage current, the lead wire contacting
the black test lead is the positive end of the electrolytic capacitor. This method of leakage current itself is small electrolytic capacitor, it is more difficult to distinguish the polarity.
3, check the variable capacitor with a multimeter
The variable capacitor has a set of stator and a set of rotor. With
a multimeter resistance file can check it move, whether there is a
touch between the films, with red and black pens, respectively, then the
film and fixed film, rotating shaft, the meter pointer does not move,
indicating that there is no short circuit between the fixed film Touch the film); If the pointer swing, indicating a short circuit capacitor.
4, with a multimeter resistor profile roughly identify the capacity of 5000PF capacitor is good or bad
With
a multimeter resistance profile can be roughly identified 5000PF
capacitor is good or bad (5000PF the following can only determine
whether the breakdown of the capacitor inside). Check
the resistance range on the range of high value, the two pens were in
contact with both ends of the capacitor, then the pointer quickly swing
about and then restore the reverse connection, swing amplitude greater
than before, and then recovered. Such a capacitor is good. The
larger the capacity of the capacitor, the larger the gauge pointer
swing when measuring, the longer the pointer recovery time, we can
compare the size of the two capacitor capacity according to the size of
the meter pointer swing.
2018-03-01
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