What is a BEC and what is its function

[wireless]

Hi Bros,

I have a question here, why is there a need for BEC for some high end ESC and what is the function of the BEC?

Last question... The BEC is connected to where? Some says the AUX1 in the Receiver and some says to the "gear" in the Receiver..

Need professional advise from Gurus,

thanks.

[Sunstorm]

BEC is the circuit that delivers power to the receiver and servos.

Most ESCs have a built in BEC incorporated.

However, some people, especially on bigger planes and nitro chose to have a dedicated 2nd power source delivering power to receiver and servos.

Hence they have a BEC device.

Also, some in-built BEC on some ESCs have problems handling multiple servos on more than 3 cells batteries. They may shut down due to excess heat or battery being drained (I heard of this only, never experienced this myself). This is more common in planes with >4 servos.

So, to be safe, a separate BEC is used.

Hope it helps.

You can by right connect BEC to any port on receiver as it only delivers power, not the signal. I personally connect it to port BATT on my spektrum receiver.

[zxyong]

But just be careful if you wanna buy an external BEC, coz some of the so called BEC are really just regulators.

For example,

External BEC (including 5.1V Step down Voltage Regulator) RCE-B3X

Features
-Using linear design, input power: 2 cell Li-ion or Li-poly battery, features no interference to receiver.

Specification
-Input voltage: DC 7.4V 2CELL Lithium battery
-Output voltage: DC 5.8V
-Max. continuous current: 3A
-Size: 60x25x6mm
-5.1V step-down voltage regulator x 1

The above is just a regulator if you use 3 cells and above, coz you cant really connect it to your main 3 cells battery as the input required is 2 cells.

Look for those that writes "2~6cells input" etc... or Universal BEC or UBEC... Those will be true Battery eliminator circuits.

And yes, where you plug it doesnt matter, any spare channels will do.

[Sunstorm]

Good point, zxyong.

So anyway wireless I recommend you just go to our local hobby shops and ask around....

Typically you use BEC when;

You have a full scale glider with about 6 or more servos...

You use glider that has no power systems

You have a nitro plane and you wanna use lipo to power the receiver and servos

You have a electric plane but you use 4 cells lipo and your ESC on board BEC may not support that many servos with a 4 cell

Your ESC doesn't come with a BEC or it is spoilt (dont ask, it happened to me)

[wireless]

Hi Bros...

Thanks for the info...

Learn something today..

[rockinanko]

thankx too, i've learn a couple of new things here!

so now my last puzzle is OPTO, what is it???

[wantime]

If i m not wrong OPTO esc, requires a separate batt pack to power up d rx n does not hv an onboard BEC.

[zxyong]

For so long i have been in this hobby, i am still trying to figure out whats the full words for OPTO...

[Abdul]

Esc Opto

For so long i have been in this hobby, i am still trying to figure out whats the full words for OPTO...

ESC OptoIsolator is a must-have for anyone experiencing signal noise problems with a normal ESC equipped with a BEC.

OptoIsolator works by physically separating the receiver and servo electronics from the motor electronics. The signal from the receiver is sent through a sealed LED/phototransistor array, assuring a clean, clear signal. While each electrical system has a different susceptibility to electrical noise, any time the
ESC and the receiver share an electrical connection, such as a power supply or even just a ground, the possibility exists for noise and interference to affect the performance of the system.

This is especially true in higher voltage and current systems. Using a secondary battery for the receiver and the servos.

OptoIsolator eliminates noise and interference from the receiver improving servo and motor response, guarding against servo jitter, and improving the stability of your model.

[JieZ]

Another question.I am using a brushed motor with 6servos onboard my C130. Do I need a Ubec?Im on 2s.

[JieZ]

Oh ya,If i were to add a UBEC,Do i need 2 battery or 1?

[blueangel]

Recent post queried about 6 servos installation and flyers had recommended me to get UBEC.

Today I experiment at home by going full trottle and check the temperature of the ESC, it was only 33 degrees. Without the UBEC, I remember it was rather warm to touch on the ESC. The UBEC took most of the heat / work from the ESC's built-in BEC circuit.

Taken from the UBEC instruction manual :

UBEC is 98% efficiency ( thus less heat produced ) It uses switching mode to convert your lipo's higher voltage to 5V ( or 6V, user selectable )

ESC's built-in BEC is only about 35% efficiency. It tries to step down your Lipo's voltage down to a permissible 5~6 volts for your receiver and servos to work. The 65% wasted energy is thus heat. This make the ESC runs very hot with high cell and servo count.


With this UBEC, I remove the red wire from the ESC. ( the 3 color wire that plugs into the receiver ). Then solder the UBEC's red wire to ESC's battery leads, black to black battery leads.

This means, the UBEC takes in voltage direct from your Lipo and then supplies the regulated voltage to your receiver. The removed red wire from the ESC now doesn't supply any voltages to the receiver, but still plugs into the trottle channel. It still has the signal and ground, so you still able to trottle.

Kinda confusing, but as long follow instruction and do, no problem.

[JieZ]

Recent post queried about 6 servos installation and flyers had recommended me to get UBEC.

Today I experiment at home by going full trottle and check the temperature of the ESC, it was only 33 degrees. Without the UBEC, I remember it was rather warm to touch on the ESC. The UBEC took most of the heat / work from the ESC's built-in BEC circuit.

Taken from the UBEC instruction manual :

UBEC is 98% efficiency ( thus less heat produced ) It uses switching mode to convert your lipo's higher voltage to 5V ( or 6V, user selectable )

ESC's built-in BEC is only about 35% efficiency. It tries to step down your Lipo's voltage down to a permissible 5~6 volts for your receiver and servos to work. The 65% wasted energy is thus heat. This make the ESC runs very hot with high cell and servo count.


With this UBEC, I remove the red wire from the ESC. ( the 3 color wire that plugs into the receiver ). Then solder the UBEC's red wire to ESC's battery leads, black to black battery leads.

This means, the UBEC takes in voltage direct from your Lipo and then supplies the regulated voltage to your receiver. The removed red wire from the ESC now doesn't supply any voltages to the receiver, but still plugs into the trottle channel. It still has the signal and ground, so you still able to trottle.

Kinda confusing, but as long follow instruction and do, no problem.

Bro, Any pics?

[blueangel]