Tutorial: UBEC

  1. Quantum's Avatar
    Quantum Quantum is offline Multi-Core Processor


    A guide to UBEC's.

    UBEC stands for Ultimate Battery Eliminator Circuit. This device converts a higher voltage source to a lower consistent voltage. Making it safer to run servos and other devices at a lower voltages.
    Compared to older BEC's that were linear and not that efficient. A UBEC uses switch-mode technology which is more efficient.

    An example:
    Using a 4S Lithium Battery Pack.

    BEC: 14.8V input and output is 5V/1A
    This comes out to 14.8Watts (14.8Watts = 14.8V * 1A) going in and being converted to
    5Watts (5Watts = 5V * 1A) at the output. This has a efficiency of 33.8%
    (Efficiency = 5Watts/14.8Watts). The difference of 9.8Watts is lost as heat.

    UBEC: 14.8V input and output is 5V/1A
    The UBEC draws only 38mA which comes out to 5.6W(5.6Watts = 14.8V * 0.38A).
    This has an efficiency of 89.3% (Efficiency = 5Watts/5.6Watts).

    **Above Data pulled from user manual.**

    There are many models available depending on input voltages and the outputs. This comes down to what is needed for your application.

    Below is a simple wire diagram of a 8A version. It shows your input which is you battery supply. It also has indicator lights that if a lithium pack was used it has a visual representation of the packs voltage. This allows the user to stop operation when voltages are low. Especially for lithium packs since they are sensitive to lower voltages that can damage and or destroy a pack. That not only can lead to cell damage but can cause fires in extreme cases due to the packs chemistry properties.

    There is a switch that allows the output voltage to be selected from either 5V or 6V. Next to the switch is your output leads. This is your converted voltage supply. It has an filter which is an ferrite ring that helps eliminate any EMI (Electromagnetic interference). But the PCB is also surround in shield which helps eliminate any interference as well. This shielding helps reduce noise when a RC receiver is used.

    Some example models are pictured below.
    Attached Files
    • UBEC Diagram
    • TR-5A-UBEC
    • Ubec