Instruction Manual for FrSky RB-20
Specifications:
Recommended input voltage range: DC 4~8.4V (1~2s Lipo or 4~6s NiMH)
Number of servos: up to 15
Operating temperature: -20
℃
~75
℃
Weight: 37g
Dimension: 77×43×22mm
Features:
High voltage servo supported
Overload protection on each channel
Compatible with other FrSky S.Port products
Dual power and dual receiver
Integrated S.Port telemetry feedbacks (voltage, current, capacity, overload indication, etc.)
Settable servo signal output period: 50Hz of servo outputs (20ms period) or equal to the input of SBUS cycle
FrSky Electronic Co., Ltd www.frsky-rc.com Contact us : [email protected]
Add:F-4,Building C, Zhongxiu Technology Park, No.3 Yuanxi Road, Wuxi, 214125, Jiangsu, China Technical Support: [email protected]
FrSky Electronic Co., Ltd www.frsky-rc.com Contact us : [email protected]
Add:F-4,Building C, Zhongxiu Technology Park, No.3 Yuanxi Road, Wuxi, 214125, Jiangsu, China Technical Support: [email protected]
Introduction:
Thank you for purchasing FrSky RB-20. It is a high-performance and multi-function unit. In order to fully enjoy the
benefits of this system, please read the instruction manual carefully and set up the device as described below.
Instruction Manual for FrSky RB-20
Working State
：
Red LED Green LED State
Off
On Normal
On
Off Abnormal
Overload Protection:
The RB-20 has overload protection function through a circuit inside on each servo output. If current overload
happens, the affected servo output will be disconnected from the power supply while the remaining servo outputs
are still power on.
The allowed continuous current output on CH1~CH15, S.PORT, RX 1IN, RX 2IN is 5A. When the continuous
current is over 10A, the RB-20 will activate overload protection immediately 23
℃.
Temperature I
hold
(A) I
trip
(A)
23
℃
5.00 10.00
50
℃
3.95 7.90
70
℃
3.35 6.70
Overview:
CH1~CH15
- connect up to 15 servos (PWM)
RX1 S.P
- connect to the S.Port of RX1
RX2 S.P
- connect to the S.Port of RX2
S.PORT
- connect to the S.Port of FrSky products with S.Port
RX1 IN
- connect to the SBUS port of the receiver
RX2 IN
- connect to the SBUS port of the receiver
BATT 1&BATT 2
- MPX connectors for batteries or BEC connection, supply power for RB-20 and connected
receivers
LED R
LED G
RX2 S.P
RX1 S.P
DC
Caution: Do not connect power supplies to CH1~CH15, S.PORT, RX1 S.P, RX2 S.P, RX1 IN and RX2 IN.
Power Supply:
Power supply of RB-20 could be provided from either one battery/BEC (connect via BATT1 or BATT2), or two
(connect to BATT1 and BATT2). When two power supplies are used, make sure both supply the maximum
continuous current of 40A and the maximum peak current of 120A. Otherwise overload protection could not
function efficiently.
If the voltages of two power supplies are the same, power can be used from both supplies at the same time;
If the voltages of two power supplies are different, the power comes from the one with the higher voltage, and
each supply is isolated from each other instead of shared.
Application of batteries with different capacity, number of cells and chemistry type is allowed.
Please ensure output power on one of the two power supplies is no less than the maximum operation power of
the connected devices (servos, etc.), or insufficient power supply on the connected devices may occur.
The RB-20 is a switchboard connected to power supplies, receivers, servos and S.Port sensors. The RB-20 does
not contain circuitry to stabilize or regulate voltage to the servos. The level of the input voltage is equal to the level
of (output) supplied voltage to the servos. Be sure to match the proper type of servos with your selected power
supply (for example: when using 2 LiPo cells without a regulator, it is necessary to use servos labeled “High
Voltage”).
Do not use Y harness to connect more than one servo to each servo output.
Connection:
1
2
3
4
5
6
7
8
SBUS
8 / 1 6 C H T E L E M E T R Y
RSSI
POR
T
SBUS
1
2
3
4
5
6
7
8
SBUS
8 / 1 6 C H T E L E M E T R Y
RSSI
POR
T
SBUS
LED R
LED G
RX2 S.P
RX1 S.P
DC
FrSky S.Port Sensors
Note
R-XSR,G-RX8 and RX8R PRO could enable/disable telemetry through S.Port.
X8R,X4R and XSR could enable/disable telemetry through S.Port with the firmware above and
V180125.
What's New!
Multi-channel output
Higher operating current (The current is twice as big as RB) and supporting high-current servos
(Please refer to the chart in Overload Protection)
Automatically selected telemetry between RX1 and RX2:
decide on/off of telemetry on RX1 and RX2 through RX1 S.P and RX2 S.P
