8
A3A
Lighted Pushbutton Switch
A
3
A
Precautions
●
Refer to the “Push-button Switches/Indicators Common Precautions” for correct use.
• Please do not perform wiring or touch
the charged parts of terminals while
power is supplied to the Switch.Doing
so may result in electric shock.
• Make sure to keep a secure insulation
distance after wiring to the Switch.
●
Mounting
• When opening a hole on a panel to
mount an A3A to the panel, make sure
that the hole has no burr.
• When mounting a flange to the
switching mechanism of an A3A,
make sure that the flange and the
casing of the switching mechanism
are engaged securely.
●
Wiring
• When soldering the terminals of an
A3A, refer to the following.
1. For manual soldering:
Use a soldering iron with the
terminals at a temperature of 350°C
maximum within three seconds.
2. Do not impose any external force on
the terminals for one minute after
the terminals are soldered.
• Do not pull the terminals of any A3A
with a force exceeding 5.34 N,
otherwise the joint part of the A3A may
be damaged.
• When soldering the terminals of an
A3A, apply non-corrosive rosin flux to
the terminals.
• After soldering the terminals of an
A3A, do not wash the A3A with any
solvent.
• When mounting an A3A to a PCB and
soldering the terminals of the A3A to
the PCB, make sure that the flux will
not rise above the surface of the PCB.
●
Operating Environment
• When using an A3A, make sure that
dust, metal powder, or oil will not
penetrate into the interior of the A3A.
●
LED
• The polarity of the LED is indicated on
the back of the Switch. Wire the LED
correctly according to the polarity.
• An A3A with a built-in LED does not
have a limiting resistor. Connect a
limiting resistor.
• The resistance can be calculated by
using the following expression.
Note: Make sure that the limiting resistor
connected to the built-in LED of an A3A
satisfies the characteristics of the built-in
LED. The mean forward current of the
built-in LED must be 8 mA minimum.
●
Example
Conditions: Red LED with an I
F
of
–10 mA at 24 V and a Ta of 25°C.
From the red LED characteristic below,
V
F
will be 2 V when I
F
is 10 mA.
Therefore, R = (24 V – 2 V)/0.01 A =
2,200
Ω
.
Thus the recommended resistance is
2.2 k
Ω
at 0.5 W (2* x I
F2
R).
Note: A factor of 2 (marked with an asterisk) is
applied because the permissible wattage of
the resistor must be twice as large as the
required wattage.
LED Characteristics
(VF – IF Characteristics)
Ta: Ambient Temperature
(Red)
(Yellow)
(Green)
●
Pushbutton
• When exchanging the Pushbutton
(except the ones for the mechanical
indicator models) with a new one, pull
out the Pushbutton from the Switch,
holding the Pushbutton in the
longitudinal direction.
Do not remove the Pushbutton of the
mechanical indicator model.
●
Engraving of Pushbutton
• Depth of engraving: 0.3 mm max. for
illuminating pushbutton
• Since the Pushbutton is made of
polycarbonate, use an alcohol-based
paint when marking legend.
●
Pressing of Pushbutton
• Apply firm pressure to the Pushbutton
when operating it. In doing so,
however, do not apply a pressure
greater than 11.8 N.
Precautions for Correct Use
R =
(
Ω
)
E : Applied
voltage (V)
V
F
: LED forward
voltage (V)
I
F
: LED forward
current (A)
E
−
V
F
I
F
50
20
10
5.0
2.0
0.1
0.2
0.5
1.0
1.0
1.5
2.0
2.5
3.0
V
F
(V)
I
F
(mA)
Ta = 25°C
50
20
10
5.0
2.0
0.1
0.2
0.5
1.0
1.0
1.5
2.0
2.5
3.0
V
F
(V)
I
F
(mA)
Ta = 25°C
Ta = 25°C
50
20
10
5.0
2.0
0.1
0.2
0.5
1.0
1.0
1.5
2.0
2.5
3.0
V
F
(V)
I
F
(mA)
