RTW281R8 TDK Corporation, RTW281R8 Datasheet - Page 17

• Manufacturer Part Number: RTW281R8
• Description: POWER SUPPLY IND 28V 1.8A 50.4W
• Manufacturer: TDK Corporation
• Series: RTWr

Specifications of RTW281R8

• Voltage - Output: 28V
• Number Of Outputs: 1
• Power (watts): 50W
• Applications: Commercial
• Power Supply Type: Switching (Open Frame)
• Voltage - Input: 85 ~ 265VAC
• Mounting Type: Chassis Mount
• 1st Output: 28 VDC @ 1.8A
• Size / Dimension: 4.88" L x 0.87" W x 3.23" H (124mm x 22.1mm x 82mm)
• Power (watts) - Rated: 50.4W
• Operating Temperature: -10°C ~ 71°C
• Efficiency: 85%
• Approvals: CE, CSA, cUL, EN, UL
• Line Regulation: 0.2%
• Load Regulation: 0.4%
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• 3rd Output: -
• 2nd Output: -
• 4th Output: -
• Other names: RTW28-1R8

Characteristics, Functions, and Applications
OUTPUT VOLTAGE VARIABLE FUNCTION(300W)
The output voltage can be adjusted by an external voltage source
by using the Output Voltage External Adjustment Function(RV) of
connectors CN2 and CN3. An RV voltage of approx.5V can pro-
duce the rated output voltage. When using this function, it is rec-
ommended to twist or burdle the wire between RV and –S
(Recommended length: 2m max.).
• Turn the output voltage adjustment trimmer(V.
• The output voltage decreases when the trimmer is turned coun-
• Connect the + of the external voltage source to the RV pin, and
• By adjusting the external voltage source the output voltage can
• If the output voltage is abruptly dropped under load, the over voltage
MASTER SLAVE FUNCTION(300W)
A use of the RV terminal enables the master slave operation.
Using connectors CN2 and CN3, connect the respective RV and
–S terminals of each power supply as shown in the diagram below.
Turn the voltage adjustment trimmer (V.
supply counterclockwise as far as it will go. Then, output voltages
of all the power supplies can be simultaneously adjusted with fol-
lowing V.
wire for the RV, –S connections.
• For two or more output loads
• All specifications are subject to change without notice.
protection may operate.
lower limit of the output voltage adjustment desired.
terclockwise.
the – to the –S pin.
be adjusted
V.
–
ADJ
V.
–
Master
CN3
CN2
Load
ADJ
CN3
CN2
CN1
Load
ADJ
RV
RV
+
–S
–S
of the master power supply. Use twisted or bundled
RV
+
–S
V.
–
ADJ
Load
CN3
CN2
–
+
External variable
power supply
RV
+
–S
ADJ
Slave
RV
–S
) of the slave power
V.
ADJ
–
ADJ
Load
) and set the
CN3
CN2
RV
+
–S
RV
–S
• For a single output load
CURRENT BALANCE (CB TERMINAL) (300W)
Equalize the output current of power supplies connected in parallel
by mutually connecting the respective CB terminals and the –S
terminals of each power supply. The maximum four power sup-
plies are connected in parallel.
(1)Conditions for current balance
(2) Uniform performance
(3) CB Terminal Connection Diagram
Equalize the impedance of the load wires coming from each
power supply.
The variation in output voltage between the respective power
supplies cannot exceed 2%
(Highest voltage–lowest voltage)
The output current is 20 to 90% of the total output rated current.
The variation in output current between the respective power
supplies does not exceed 10%
Use a twisted wire or a shielded wire for the wiring from CB and
–S (shielded wire for –S).
Equalize the impedance of the load wires coming from each
power supply.
Master
Master
V.
V.
–
–
ADJ
ADJ
CN3
CN2
CN3
CN2
RV
CB
RV
CB
CB
CB
+
+
–S
–S
–S
–S
V.
V.
–
–
ADJ
ADJ
Load
Load
CN3
CN2
CN3
CN2
RV
CB
CB
+
–S
+
–S
÷
004-02 / 20060214 / ea111_rtw.fm
rated voltage=2% max.
RV
CB
CB
–S
–S
Slave
V.
V.
–
–
ADJ
ADJ
Slave
CN3
CN2
CN3
CN2
RV
CB
CB
+
+
–S
–S
(17/19)
RV
CB
CB
–S
–S