rr2ba-ul-ac6 IDEC Corporation, rr2ba-ul-ac6 Datasheet - Page 6

• Manufacturer Part Number: rr2ba-ul-ac6
• Description: Ru/rr/rh/rm/ry & Latch Relays Relays Sockets
• Manufacturer: IDEC Corporation

Operating Instructions
Driving Circuit for Relays
1. To make sure of correct relay operation, apply the rated
2. Input voltage for the DC coil:
3. Operating the relay in synchronism with AC load:
4. Leakage current while relay is off:
5. Surge suppression for transistor driving circuits:
6
voltage to the relay coil.
A complete DC voltage is best for the coil power to make
sure of stable relay operation. When using a power supply
containing a ripple voltage, suppress the ripple factor
within 5%. When power is supplied through a rectification
circuit, the relay operating characteristics, such as pickup
voltage and dropout voltage, depend on the ripple factor.
Connect a smoothing capacitor for better operating char-
acteristics as shown below.
If the relay operates in synchronism with the AC power
voltage of the load, the relay life may be reduced. If this is
the case, select a relay in consideration of the required
reliability for the load. Or, make the relay to turn on and off
irrespective of the AC power phase or near the point
where the AC phase crosses zero voltage.
When driving an element at the same time as the relay
operation, a special consideration is needed for the circuit
design. As shown in the incorrect circuit below, a leakage
current (Io) flows through the relay coil while the relay is
off. The leakage current causes the coil release failure or
adversely affects the vibration resistance and shock resis-
tance. Design the circuit as shown in the correct example.
When the relay coil is turned off, a high-voltage pulse is
generated, causing the transistor to deteriorate and
sometimes to break. Be sure to connect a diode to sup-
press the counter electromotive force. Then, the coil
release time becomes slightly longer. To shorten the coil
release time, connect a Zener diode between the collector
and emitter of the transistor. Select a Zener diode with a
Zener voltage slightly higher than the power voltage.
Operating Instructions
V
Incorrect
in
R
R
Io
TE
Smoothing
capacitor
Load
+
–
Counter emf
suppressing diode
R
Relay
E
TE
AC
E
V
Ripple factor (%) =
Emax = Maximum of pulsating current
Emin
Emean = DC mean value
AC
in
Correct
+
–
R Relay
= Minimum of pulsating current
Emin Emax Emean
R
Emax – Emin
Emean
Pulsation
×100%
DC
Protection for Relay Contacts
1. The contact ratings show the maximum values. Make
2. Contact protection circuit:
3. Do not use a contact protection circuit as shown below:
Soldering
1. When soldering the relay terminals, use a soldering iron
2. Use a non-corrosive rosin flux.
sure that these values are not exceeded at any instant.
When an inrush current flows through the load, the con-
tact may be welded. If this is the case, connect a contact
protection circuit, such as a current limiting resistor.
When switching an inductive load, arcing causes carbides
to form on the contacts, resulting in an increased contact
resistance. In consideration of contact reliability, contact
life, and noise suppression, use of a surge absorbing cir-
cuit is recommended. Then, note that the release time of
the load becomes slightly longer. Check the operation
using the actual load. Incorrect use of a contact protection
circuit will adversely affect the switching characteristics.
Four typical examples of contact protection circuits are
shown in the following table:
Generally, switching a DC inductive load is more difficult
than switching a DC resistive load. Using an appropriate
arc suppressor, however, will improve the switching char-
acteristics of a DC inductive load.
of 30 to 60W, and quickly complete soldering within
approximately 3 seconds.
Power
Power
Power
Power
Power
Power
+
–
C
C
Load
Load
Varistor
C R
D
C
R
This protection circuit is very effective in arc sup-
pression when opening the contacts. But, the capac-
itor is charged while the contacts are opened. When
the contacts are closed, the capacitor is discharged
through the contacts, increasing the possibility of
contact welding.
This protection circuit is very effective in arc sup-
pression when opening the contacts. But, when the
contacts are closed, a current flows to charge the
capacitor, causing contact welding.
Ind. Load
Ind. Load
Ind. Load
Ind. Load
This protection circuit can be used
when the load impedance is smaller
than the RC impedance in an AC load
power circuit.
R: Resistor of approximately the same
C: 0.1 to 1 µF
This protection circuit can be used for
both AC and DC load power circuits.
R: Resistor of approximately the same
C: 0.1 to 1 µF
This protection circuit can be used for
DC load power circuits. Use a diode
with the following ratings.
Reverse withstand voltage:
Forward current:
This protection circuit can be used for
both AC and DC load power circuits.
For a best result, when using on a
power voltage of 24 to 48V AC/DC,
connect a varistor across the load.
When using on a power voltage of 100
to 240V AC/DC, connect a varistor
across the contacts.
Power voltage of the load circuit × 10
More than the load current
resistance value as the load
resistance value as the load
(04/10/25)