Need help on BEC ???

Hi saw some ppl servo connect to BEC
now to double check does RTR wraith need a BEC on the stock servo or just the stock ECS build in BEC good enough
In what situation than I need to use BEC.
what amp BEC should I use for the stock servo
If I'm use a XQ-S4120D 20kg High Voltage Digital Servo (7.4-8.4V 2S Lipo)
What amp BEC should I use
LHS do have CC BEC & UBEC so what are the different

derrickwthip4 wrote:Hi saw some ppl servo connect to BEC
now to double check does RTR wraith need a BEC on the stock servo or just the stock ECS build in BEC good enough
In what situation than I need to use BEC.
what amp BEC should I use for the stock servo
If I'm use a XQ-S4120D 20kg High Voltage Digital Servo (7.4-8.4V 2S Lipo)
What amp BEC should I use
LHS do have CC BEC & UBEC so what are the different

It is better to use a BEC for crawler servo, in case the servo damage , it will protect the receiver. A 5Amp 6v BEC is enuff for normal 6V servo.
For Xq-S4120 HV servo no BEC require. You can connect the lipo bat directly to the brown and red color of the servo wires. The signal orange color wire connect to the receiver.And jump the servo brown to the rx negative.
I am thinking of getting tis servo too.

Normally what are the price on the BEC u mention?
I already check the price for this XQ-S4120D 20kg High Voltage Digital Servo (7.4-8.4V 2S Lipo)
selling at $82, if buy online + shipping cost+BEC = near to the price of XQ-S4120D n no need BEC I thing I get it in our LHS

BEC rotor hobby selling cheap. Can't remember how much, i think less then $10.

Hi, i used the XQS4120D on my AX10 and the XQS4013D on my Wraith, they works great.

I'm already add this item on my buying list tks for ur info

ShaiAX55 wrote:Hi, i used the XQS4120D on my AX10 and the XQS4013D on my Wraith, they works great.

Bro , can the XQS4120D submerge under water?

Not sure leh but from the write out mention water proof check this link
http://www.jethobby.com.sg/cgi-bin/ezsite/prod/manager.cgi?action=show&pid=3044&cid=82&idx=1&gid=5

Just got tis info from boopek. Those wiring the BEC to their servo.
Remember to short all negative wires togather to reduce interference and even power distribution to your component.

derrickwthip4 wrote:Not sure leh but from the write out mention water proof check this link
http://www.jethobby.com.sg/cgi-bin/ezsite/prod/manager.cgi?action=show&pid=3044&cid=82&idx=1&gid=5

Can see a lot of O rings but dunno can fully submerge. Did anyone try b4?

RTECH wrote: Just got tis info from boopek. Those wiring the BEC to their servo.
Remember to short all negative wires togather to reduce interference and even power distribution to your component.

i wanted to draw out how i connected the BEC... but before drawing, managed to find one diagram of the BEC wiring... so saved my effort drawing...

Basically, if you are using the BEC to power the rx and the servo, can just remove the red pin from the esc bec output wire before plugging into channel 2 of the rx

Then the external BEC input goes to your battery, output goes to the battery input of the rx... then servo just plug into channel 1 as per normal....
as easy as that, this is how i wired...

As for my case, i a bit kiasu. I use 2 BEC, one is the esc BEC and the other is the external BEC.
I connect the lipo directly to the external BEC, then the BEC out directly to the servo brown and red power wires.
The servo orange signal wire plug to the rx. This will work also. Then i link the external BEC black wire with the esc black wire (recomand by boopek). Anyway without joining the 2 negative black will also work, but may cause interference.

Why i do so troublesome is that i dun want the high power servo to share the same external BEC with the receiver.
If anything short circuit, i only wan half of the circuit to damage only. Although the current will flow thru the easlier path but still using the rx tracks as the path.
I dun want to use the rx pcb as a junction to transfer the high current.

If i use HV servo, i will just remove the external BEC and connect the lipo to the servo using hardwire.

Something like that....

My method is not necessary, I a bit kiasu. Haha...

Hi I just bought a HobbyWing UBEC 
1) 3A,Max 5A
Remark: As mention on manual (Output:5V/3A and 6V/3A switchable) so I should switch to 5V or 6V? (Using on my Wraith stock servo with NiMH 4200mAh 7.4v)

2)What's  the different between CC BEC & UBEC hope I not getting the wrong type of BEC!!! 
Hope to receive some info tks :-)

derrickwthip4 wrote:Hi I just bought a HobbyWing UBEC 
1) 3A,Max 5A
Remark: As mention on manual (Output:5V/3A and 6V/3A switchable) so I should switch to 5V or 6V? (Using on my Wraith stock servo with NiMH 4200mAh 7.4v)

2)What's  the different between CC BEC & UBEC hope I not getting the wrong type of BEC!!! 
Hope to receive some info tks :-)

Hi bro,
both BEC and UBEC refers to the same thing.... BEC could be referring to linear BECs... and UBEC refers to switch mode BECs...

linear BEC is not efficient especially when using higher voltages to step down... generates a lot of heat....

switch mode BEC generate very little heat, very efficient stepping down of voltages... downside is it generate a lot of noise... as in RF noise... but not a big issue for us la...

set the UBEC to 6V if your servo and Receiver can take 6V (should be able to... check the manual) for a little more torque for the servo...

Hey tks last QnA about the wiring connection check this link
http://helidirect.com/3a-5v6v-switch-mode-ubec-p-1449.hdx
Should I use the connection as mention on the manual, urs or Rtech ?

derrickwthip4 wrote:
Hey tks last QnA about the wiring connection check this link
http://helidirect.com/3a-5v6v-switch-mode-ubec-p-1449.hdx
Should I use the connection as mention on the manual, urs or Rtech ?

Dun use my method, my one is not necessary and is complicated. The manual connection same as boo connection.

The swtiching BEC looks like comes with a noise reduction inductance coil liao.

Don't worry bro if some things happen will not ask u to bear the responsibility joking only
Ok come back to the QnA
Using manual method:-
http://helidirect.com/3a-5v6v-switch-mode-ubec-p-1449.hdx

1) BEC Out to receiver batt channel right?
2) Just disconnect the Red wire from the throttle channel right?

derrickwthip4 wrote:Don't worry bro if some things happen will not ask u to bear the responsibility joking only
Ok come back to the QnA
Using manual method:-
http://helidirect.com/3a-5v6v-switch-mode-ubec-p-1449.hdx

1) BEC Out to receiver batt channel right?
2) Just disconnect the Red wire from the throttle channel right?

Yup, the red and black pins on the rx are all same togather no matter which channel you plug.
Just be sure to remove that red wire from the esc, just plug in the black and signal(white or orange) into rx.

I just update the schematic for my connection above. Forget about the OSD/UAV in the schematic.

RTECH wrote:

derrickwthip4 wrote:Hi saw some ppl servo connect to BEC
now to double check does RTR wraith need a BEC on the stock servo or just the stock ECS build in BEC good enough
In what situation than I need to use BEC.
what amp BEC should I use for the stock servo
If I'm use a XQ-S4120D 20kg High Voltage Digital Servo (7.4-8.4V 2S Lipo)
What amp BEC should I use
LHS do have CC BEC & UBEC so what are the different

It is better to use a BEC for crawler servo, in case the servo damage , it will protect the receiver. A 5Amp 6v BEC is enuff for normal 6V servo.
For Xq-S4120 HV servo no BEC require. You can connect the lipo bat directly to the brown and red color of the servo wires. The signal orange color wire connect to the receiver.And jump the servo brown to the rx negative.
I am thinking of getting tis servo too.

Hi sorry what u mean jump the servo brown to the rx negative, is it connect another wire from servo to RX negative ???

boolean21 wrote:

Then the external BEC input goes to your battery, output goes to the battery input of the rx... then servo just plug into channel 1 as per normal....
as easy as that, this is how i wired...

Hi what if my rx dont have battery input , it only have AUX , throttle , steeling and bind/rs input. Like this the BEC output go to which one? AUX or Bind/rs.

My is spektrum SR3300T RX. Many thanks

ket2175 wrote:

boolean21 wrote:

Then the external BEC input goes to your battery, output goes to the battery input of the rx... then servo just plug into channel 1 as per normal....
as easy as that, this is how i wired...

Hi what if my rx dont have battery input , it only have AUX , throttle , steeling and bind/rs input. Like this the BEC output go to which one? AUX or Bind/rs.

My is spektrum SR3300T RX. Many thanks

On the rx , the black and red pins are all the same for steering, throttle, AUX or bat.
Just make sure when you plug your BEC into the rx, the black and red wires is correct.
You can plug into any unuse socket.
For the bind socket , i am not sure whether can use. Anyone knows?

RTECH wrote:

ket2175 wrote:

boolean21 wrote:

Then the external BEC input goes to your battery, output goes to the battery input of the rx... then servo just plug into channel 1 as per normal....
as easy as that, this is how i wired...

Hi what if my rx dont have battery input , it only have AUX , throttle , steeling and bind/rs input. Like this the BEC output go to which one? AUX or Bind/rs.

My is spektrum SR3300T RX. Many thanks

On the rx , the black and red pins are all the same for steering, throttle, AUX or bat.
Just make sure when you plug your BEC into the rx, the black and red wires is correct.
You can plug into any unuse socket.
For the bind socket , i am not sure whether can use. Anyone knows?

Ok noted , thanks so much.