User Manual of 8A UBEC
The voltage of the lithium battery pack
The voltage of the battery pack is just
at the critical edge of each range.
8 Amps Switching-Mode UBEC
1. Why do you need UBEC?
The 8A-UBEC is a switching-mode DC-DC regulator supplied with a 2-3 cells lithium battery pack
and outputs a consistent safe voltage for your receiver, gyro and servos. It is very suitable for nitro
powered RC helicopter (above 30 class) and big fixed-wing aircraft.
Compared with the linear mode UBEC, the overall efficiency of the switching-mode BEC is much
higher, so it can extend the working time of the receiver battery pack, and because a switchingmode UBEC can significantly reduce the heat emission, it can avoid the loss of control caused by
the over-heat problem which is frequently happened with the linear mode UBEC.
2. Specification:
2.1. Output: 5V/8A or 6V/8A (Changeable with an output-voltage select switch )
2.2. Input: 6V-12.6V (2-3 cells lithium battery pack)
2.3. Size: 42mm*39mm*9mm (length*width*height)
2.4. Weight: 38g
2.5. Quiescent current: 60mA
3. Features:
3.1. Designed with an advanced switching-mode DC-DC regulator IC.
3.2. The output current is very large, the continuous output current is up to 8A, and the burst
output current is 15A.
3.3. Output short-circuits protection function.
3.4. A metal shield covers almost all the electronic components, and a specially made filter
(ferrite ring) is attached with the output wires to significantly reduce the electromagnetic
interference.
3.5. Automatically detects the number of the lithium battery pack (2 cells or 3 cells), and shows
the battery capacity with 4 indicators (LEDs).
3.6. Shows the working status with an indicator (LED), lights when the output is in normal range.
3.7. 2 output leads to reduce the resistance when connecting the UEBC to the receiver.
3.8. Accessory: A step-down voltage regulator with 0.7V down (from 6.0V to 5.3V).
4. Wiring
5. Special Notes
5.1. Although we have tried our best to reduce the electromagnetic interference caused by
switching-model UBEC, it still may cause some interference to the receiver. So please
install the filter far away from the 8%(&¶s main board, and DON¶T stack the filter on the
main board. Please put the whole UBEC as far as possible away from the receiver.
Input
Voltage Indicators ˄4LEDs˅
Full Mid Low Stop
Output
Output Voltage-changing Switch
Output Indicator
5.2. This UBEC is only designed for using lithium battery pack; NiMH / NiCd battery pack is not
recommended.
5.3. The input polarity must be correct; otherwise the UBEC will be damaged. Please check the
polarity carefully before connecting the battery pack.
6. How to Use the UBEC?
6.1. Change the output voltage
The voltage is changed by an output-voltage selection switch.
6.2. Working status indicator (LED)
The LED shows the status of the output. It lights when the UBEC has the normal output. If
it FRXOGQ¶t light, please check the battery connections.
6.3. Battery capacity indicators (4 LEDs)
ƻ means the LED lights, ƽ means the LED does not light
6.4. Turn on or turn off the UBEC
6.5. About the 0.7V step-down voltage regulator
LED Status
Full Mid Low Stop 2S battery pack 3S battery pack
ƻ ƻ ƻ ƻ 7.8ˉ8.4V 11.7ˉ12.6V
ƽ ƻ ƻ ƻ 7.2ˉ7.8V 10.8ˉ11.7V
ƽ ƽ ƻ ƻ 6.6ˉ7.2V 9.9ˉ10.8V
ƽ ƽ ƽ ƻ 5.4ˉ6.6V <9.9V
4 LEDs flash
at the same time
One LED flashes for
a short time
When you are using a 3 cells lithium battery pack, if there is only one LED ("STOP") lights,
that means the voltage is less than 9.9v, please change the battery pack as soon as
possible to avoid the possible damage caused by over-discharging. For such a
fully-discharged 3S battery pack (the voltage is less than 9V), please don¶t use it again
before it is recharged, otherwise the UBEC may mistakenly consider this battery pack as 2
cells, then the battery capacity indication function cannot work properly.
Set the main switch to the "ON" position to turn on the UBEC; Set the main switch to the
³2))SRVLWLRQ to turn off the UBEC.
The 0.7V regulator is used for servos cannot work with 6V (including Futaba servo 9241,
9251, 9253, 9254, 9255, 9256 and etc). It changes the voltage from 6V to 5.3V. When the
UBEC output is set to 6V, please connect the regulator between the receiver and the above
servos.
If you are using a servo can work with 6V input, the 0.7V regulator is unnecessary..
1)The voltage <5.4V
2)The voltage >13.5V
1)The voltage >13.5V
2