Bec ??

[sgtlopez79]

Ok I am a newb to this and I just scored a CC MMP. I have not chosen a motor yet but my question is what is a BEC and what does it do? I have seen that most everyone is running a BEC with the MMP and I have no clue what its for yet alone which one to choose. Any help would be greatly appreciated.

[jeepster73]

Try the search function too


A battery eliminator circuit (BEC) is an electronic circuit designed to deliver electrical power to other circuitry without the need for a battery. Historically the expression was sometimes used to describe devices used to power battery-driven equipment from mains electricity. This is still the case in many products offered in retail electronic supply stores.
Contents [hide]
1 Radio-controlled (R/C) models
2 Vehicles
3 See also
4 External links
Radio-controlled (R/C) models [edit]

In an electric-powered radio controlled model, the BEC is typically part of the electronic speed control (ESC). BEC allows such a model to carry only one battery (the motive power battery) instead of two (motive power, and a separate battery to operate the R/C equipment). A BEC-equipped ESC meant for airplane use often incorporates a low-voltage-cutoff (LVC) circuit which can sense the voltage drop caused when the battery has little charge left in it. It then cuts the power to the 'drive' motor in order to provide the 'steering' servo(s) with enough power to be able to bring the model safely back to the operator. The power to the propeller would be cut but the operation of the control surfaces would be maintained in order to perform a dead-stick landing. Without this feature, all control would be lost when the battery expired, probably resulting in the destruction of the model. In some cases, the BEC is part of the radio control receiver, instead of being part of the ESC.
R/C BECs in their simplest form use a linear fixed voltage regulator with its standard circuit suggested in the manufacturer's datasheet – usually the power supply of the receiver needs 5 V. Low-drop types are preferred – especially for batteries with only a few cells. For small models, 1.5 to 2 A are enough; for mid-size models a 3 A type needs to be considered. BECs for large models have to provide current of 5 A or more. There a more complicated switched-mode regulator should be used, as the BEC has to deal with losses. These losses are proportional to the difference of the target voltage of 5 volts and the voltage of the main battery; as well as they are proportional to the provided current. For example, take a 10-cell (NiMh) accumulator with a normal voltage of 12 volts. With a peak current of 5 A, the BEC will have losses of (12 V − 5 V) × 5 A = 35 W. With a linear regulator, these 35 W will be converted to heat and so require a large heat sink. In all cases, it is a good idea to mount some large capacitors to buffer the regulated output. In large plane or ship models, another possibility is to buffer the power supply with a further capacitor near the actuator's (servos).

[SwampDawg]

if you run a high powered servo, then wire in a CC BEC

Red/Black wires from BEC to battery directly.

Red/Black from servo to BEC Red/Black (smaller wires)
Signal wire from servo to Rx (depends on servo, could be yellow, white or orange)
**the red/black are usually a dead give away to decipher which is signal off the servo**

[Postclanker]

You are very kind Jeepster....
You could have flamed the boy

[xCoolHandLukex]

If your crawlimg or traveling at low speeds with it put one in. If your bashing at high speeds you won't know the difference. I have a BEC in my slash and Rustler and I couldn't tell any difference in performance out of the 7954 servo.