Why do you need a big switching uBEC?
most small ESC run MOSFETs on one side and a separate 5v circuit on the other - heat or electronic noise from the onboard BEC can increase the risk of a) thermal run-away on the important MOSFET side or b) subject your sensors to EMI causing FPV glitches or autopilot flips - on large more expensive multicopters smart pilots will use a remotely located (90mm from anything else) switching uBEC to supply power to hungry devices like servos or gimbals. This 8A-uBEC (2-6S) is a switching-mode DC-DC regulator supplied with 2-6S Lipo battery pack - featuring a burst 15a (hard servo reversals); it outputs a consistent safe voltage for your receiver, gyro, servos and other electronic equipments. Compared with the linear mode BEC, the efficiency of the switching-mode BEC is much higher especially when the input voltage is higher than 14.8V (4S Lipo). So the switching-mode BEC is strongly recommended when the RC model uses high voltage battery pack (more than 4S Lipo or 12 cells NiMH). The UBEC is very suitable for large servo RC helicopters and big fixed-wing aircraft.
When using OPTO ESC - ie ESC that do not have a built-in BEC - the Recommended type for large copters
No change is needed for the ESC, just connect the input wires of UBEC to the battery, and plug the output lead (connector) of the UBEC into one spare channel of the receiver.
When the ESCs have built-in BEC - less ideal for large 7kg Multicopters
You must disable the built-in BEC of the ESC (that is, cut the red wire in the trio of Rx (receiver)
You can use a small screwdriver to lift the tab and pull the red pin (with red wire) out from the BEC connector of your ESCs, and then insulate it with heatshrink, so you needn’t cut the red wire by this method. The red wire is used during programming of ESC.
Noise - Although we have done our best to reduce the electromagnetic interference caused by this switching-model UBEC, but it still may cause some interference to receiver. So please install the UBEC far away from the receiver, sensors, IMU, FPV gear (The distance > 90mm is recommended).
The input polarity must be correct; otherwise the UBEC will be damaged immediately. Please check the polarity carefully before connecting the battery pack.
How to Use the UBEC?
Changing the output voltage. The voltage is changeable by using the output-voltage selection switch fro 5v or 6v - becareful ! PARIS and DJI electronics only run on 5v.
Working status indicator (LED). The LED shows the status of the output. It lights when the UBEC works normally. If it couldn’t light, please check the battery connections.
Optional - the 0.7V step-down voltage regulator. The 0.7V step-down voltage regulator is necessary for the 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 0.7V step-down regulator between the receiver and the above servos. If a servo can work with 6V input, then the 0.7V regulator is unnecessary.