Instruction Manual
Item-No. 86010010
3A Switch-Mode UBEC
1. Why do you need UBEC?
The UBEC is a switch-mode DC regulator separated from ESC (ESC---Electronic Speed
Controller for brushless/brushed motor), it will take high-voltage (5.5V to 26V) power from your
battery pack and convert it to a consistent safe voltage for your receiver, gyro and servos.
For traditional speed controller with a built-in BEC, it will very likely have only a limited ability to
supply power to your receiver and servos without overheating. If you are using a high-voltage
battery pack or have heavy servo load, you should consult the ESC specifications to determine
what the stated recommendations or limitations are. In general, if you are using a 4 cells lithium
battery pack, or more than a 12 cells Nickel based battery pack, you should consider using an
UBEC because in such a case the built-in BEC of the ESC can support only 2 servos, which
means it is not suitable for RC helicopter and big aircraft.
2. Specification:
2.1.
Output:
5V/3A and 6V/3A switchable
2.2.
Ripple:
<50mVp-p(@2A/12V)
2.3.
Input:
5.5V-26V (2 to 6 cells Lipo battery pack, 5 to 18 cells NiMH battery pack)
2.4.
Size:
51mm*16.6mm*8.5mm (length*width*height)
2.5.
Weight:
11.5g
3. Features:
3.1. The UBEC is an advanced switching regulator with over-current and over-heat protection
function, and the maximum efficiency of the system is nearly 90%.
3.2. The small size and the light weight make it very convenient to use.
3.3. The comparison of linear BEC and switch-mode BEC: When using a lithium battery pack
more than 3S, a switch-mode BEC has much higher efficiency than linear BEC.
• For a traditional linear BEC, For example, a 4S lithium battery pack has a typical voltage of
14.8V, in order to let BEC output 5V/1A, the current flow into the BEC is at least 1A, so the po
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wer on BEC is 14.8V* 1A=14.8W. But the useful output power is only 5V*1A=5W, so the effici
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ency of the linear mode BEC is just 5W/14.8W=33.8%, the redundant power 14.8W-5W=9.8W
changes to heat, which makes the BEC very hot.
• For a switch-mode BEC in the above case, in order to let BEC output 5V/1A, the current flow
into BEC is only 0.38A (actual test data), so the power on BEC is 14.8V* 0.38A =5.6W, and the
efficiency of BEC is 5W/5.6W=89.3%.
