When using aluminum electrolytic capacitors, pay strict attention to the following：
Polarized aluminum electrolytic capacitors.
If you should reverse the polarities of aluminum
electrolytic capacitors, it would lead to
short-circuited circuitry and many further results in
an explosion if the unit were kept energized. We
offer units of φ 8 or more with safety vent design as
the standard type in order to prevent possible
accidents that may take place if the unit should be
connected with its polarities. Small-size capacitors
(φ5 ~ φ6) with safety vents are available on request.
It is advisable to the use non-polar capacitors for a
DC circuit where the polarity is reserved.
Do not apply any over-voltage exceeding the
rated voltage (surge voltage for a short period)
to the capacitor.
When applying ripple current to the capacitor, be
very careful not to allow the peak voltage value (a
value obtained by adding the ripple voltage to the
DC voltage) to exceed the rated voltage.
Application of any voltage higher than the rated
value would lead to shortened service life of the
capacitor or would even destroy the unit in a short
period.
However, the unit may withstand extremely short
application of surge voltage.
Ascertain the operating temperature range.
Use the electrolytic capacitors according to the
specified operating temperature range. Usage at
room temperature will ensure longer life.
Reverse voltage
The reverse voltage shall not exceed 2V.
(The sum of DC voltage peak ripple voltage shall
not exceed-2V.)
tan δ/E.S.R.
The maximum value of tan δ is specified in each
table which is measured at 120Hz and 20℃, unless
otherwise specified. E.S.R. can be obtained from
the following formula.
E.S.R. = tan δ/2π.f. C.
Where: f
= measurement frequency in Hz
C = measurement capacitance value in F
Electrolytic capacitor is not suitable for circuits
in which charge + discharge are frequently
repeated
If used in circuits, in which charge and discharge
are frequently repeated, the capacitance value may
drop, or the capacitor may be damaged. Please
consult our engineering department for assistance
in these applications.
Do not allow any higher ripple current than
rated to flow through capacitor.
If any ripple current higher than the rated value is to
flow through a capacitor, excessive heat will be
generated and the capacitance reduced with
resultant shortened life. We offer high ripple
resistant capacitors especially designed for use with
high ripple current on request.
Ripple current
The capacitor should be used within specified
permissible ripple current in each standard products
table. (The sum of DC voltage and voltage shall not
exceed the rated DC working voltage.)
The specified maximum permissible ripple current
is defined at + 85℃ and 120Hz, unless otherwise
specified.
In other condition of ambient temperature and
frequency, ripple current multiplied by following
multiplier can be applied as maximum permissible
ripple current.
Temperature
40℃
60℃
70℃
85℃
105℃
Multiplier
1.9
1.5
1.3
1.0
0.6
Frequency
60HZ
120Hz
300Hz
1KHz
Multiplier
0.7
1.0
1.1
1.3
10KHz 100KHz
1.4
1.4
When you see a capacitor after prolonged
storage.
An aluminum electrolytic capacitor, which has been
stored for a long period, tends to give increased
leakage current. Accordingly, whenever you use a
capacitor that has been long stored, make sure to
gradually increase the voltage to the rated value.
Since the leakage current tends to be higher with
higher storage atmosphere temperatures, store the
units at a location with storage temperatures of 40 to + 40℃ which is not exposed to direct sunlight.
Be careful of temperature and time when
soldering.
When soldering a printed circuit board with various
components, care must be taken that the soldering
temperature is not too high and that the dipping
time is not too long. Otherwise, there will be
adverse effects on the electrolytic capacitor. In the
case of small sized electrolytic capacitor, nothing
abnormal will occur if dipping is performed at less
than 260℃ for less than 10 seconds.
Common application conditions to avoid
If the loads shown below are applied to a capacitor,
then its characteristics may degrade rapidly or it
may short-circuit. Rapid heat or gas generation may
occur, which leads to the activation of the pressure
valve. Electrolytes will then leak from the sealing
section. In the worst case, an explosion or ignition
may occur.
When the capacitor breaks down, combustible
materials (electrolytes, element fixing materials,
etc.) may flow externally in all directions.
(1) Polarity
Aluminum electrolytic capacitors have
polarities.
Do not apply a reversed at
alternating-current voltage.
If the polarity is reversed, then
short-circuiting may occur in the initial state
or the pressure valve may be activated,
leading to capacitor breakdown.
Check the polarity when using a polar
capacitor.
If the polar is unstable or unclear in a circuit,
then use bipolar capacitors. However,
bipolar capacitors cannot be used in
alternating current circuits.
(2) Applied voltage
Do not apply an excessive voltage
(voltage exceeding the rating).
The peak direct current voltage superposed
with a ripple voltage (alternating current
component) must be equal to or less than
the rated voltage. A surge voltage
exceeding the rated voltage is allowed and
specified. However, the allowable
conditions are limited and the specifications
do not guarantee the application of such a
surge voltage for a long time.
(3) Ripple current
Do not allow an excessive current
(current exceeding the rated ripple
current) to pass.
If an excessive ripple current passes
through, then the amount of internally
generated heat will grow, the capacitor life
will be reduced, or the pressure valve will
be activated, leading to breakdown.
Even if the current is equivalent to or less
than the allowable level, a reversed voltage
may be applied when a direct current bias
voltage is low.
Use capacitors so that a reversed voltage is
not applied.
(4) Charging/discharging applications
Do not use general-purpose capacitors in
rapid charging/discharging circuits.
Please contact us for capacitors to be used
in circuits where rapid charging/discharging
is repeated.
(5) Series/parallel connection
[Parallel connection]
If capacitors are connected in parallel, then
the balance of currents between these
capacitors may be disrupted and an
excessive ripple current may pass through
only part of these capacitors.
Wire your circuits such that excessive ripple
current does not pass through the
capacitors.
[Series connection]
If capacitors are connected in series, then
the balance of voltages between these
capacitors may be disrupted and excessive
voltage may be applied. Add a bleeder
resistor in parallel with each capacitor. By
taking leak currents into consideration the
balance of voltages will not be disrupted.
(6) Electrical isolation of the capacitors
Isolate capacitors completely in a circuit
in the following cases.
Between the housing and cathode and
anode terminals and between circuit traces.
Between stand-alone non-connected
terminals (for reinforcing) and cathode and
anode terminals and between circuit traces.
(7) Capacitor sleeve
Exterior sleeves or lamination covering
capacitors are for indication purposes only
and do not guarantee electrical insulation.