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 out-
puts 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 switching- mode 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 cur-
rent 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 bat-
tery 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
Voltage Indicators (4 LEDs)
Output Voltage-changing Switch
Output Indicator
Output
Input
5.
Special Notes
5.1.
Although we have tried our best to reduce the electromagnetic interference caused by switch-
ing-model UBEC, it still may cause some interference to the receiver. So please install the filter far
away from the UBEC’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.
User Manual of 8A UBEC
5.2.
This UBEC is only designed for using lithium battery pack; NiMH / NiCd battery pack is not recom-
mended.
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 couldn’t
light, please check the battery connections.
6.3.
Battery capacity indicators (4 LEDs)
LED Status
The voltage of the lithium battery pack
Full
Mid
Low
Stop
2S battery pack
3S battery pack
○
○
○
○
7.8 – 8.4V
11.7 – 12.6V
●
○
○
○
7.2 – 7.8V
10.8 – 11.7V
●
●
○
○
6.6 – 7.2V
9.9 – 10.8V
●
●
●
○
5.4 – 6.6V
<9.9V
4 LEDs flash
at the same time
1) The voltage <5.4V
2) The voltage >13.5V
1) The voltage >13.5V
One LED flashes for
a short time
The voltage of the battery pack is just
at the critical edge of each range.
○ means the LED lights, ● means the LED does not light
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.
6.4.
Turn on or turn off the UBEC
Set the main switch to the “ON” position to turn on the UBEC; Set the main switch to the “OFF” po-
sition to turn off the UBEC.
6.5.
About the 0.7V step-down voltage regulator
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.
