BEC problem???

[Adrianli]

Last Sat, while playing boat for abt 2mins already, the boat suddenly stopped operating and I managed to retrieve it. Initially tot it was ESC cut or burnt but instead it was the external BEC stopped working. I tot the BEC gone liao as there was no power to the Rx n my cooling fans.

Pack up n brought it home to check. Using 4 AA cells, I powered up the Rx n ESC without any problem. Dry running the motor was smooth as usual. So main suspect is BEC. Plug in a load to the BEC, LEDs, it powered up w/o problem at all. Tis is funny, I tot its not working. Plugged the BEC to the Rx, it stopped working.

The brand of tis BEC is Hobbywing 3A.

Desolder the BEC from the ESC wires and soldered a brand new Himodel BEC 3A to the ESC. Faced the same problem!!! No power to Rx n Fan when plugged in. The I plugged it directly to the LEDs, they light up. Now I suspect the Rx got problem.

I tried it on another Rx, same problem!!!

Using the 4 AA cell, I got no problem at all. Whatz wrong now???

[skyblueblue]

Could be oxidization of the connection pin either on the rx or esc side.

u can't really see the oxidization coating forming but that would somehow give a weak contact and stop the electric flow

But i can't figure out why a brand new bec don't work. Did u try pluging the bec to other channel ?

[Adrianli]

I connect it to another rx also same problem. Cant figure it out.

[skyblueblue]

the connector of the ESC to the rx could have rusted also ? Did u try the bec on seperate pack ?

[Adrianli]

No rust found.

I did try different packs, 2S 1700mah Etecs, 2S 2200mah Hxt n 4S2P 2200mah Saphion.

Still scratching my head on tis problem.

[X34]

check Bec output voltage

[Adrianli]

BEC output should be 5V as the LEDs were rated to 5V wif resistors.

[skyblueblue]

maybe u should try after the 7th month, everything should be fine by then

[genexis]

what is your min input voltage of your bec ... sometimes your AA batteries are too low already, so cannot power up your bec.

[Adrianli]

I tink something wrong wif the ESC. It is an opto 100A Himodel ESC. I tried remove the red wire, it cannot run but the BEC was able to power up the Rx n Fan.

Wat does that mean???

[Super-Hornet]

I tink something wrong wif the ESC. It is an opto 100A Himodel ESC. I tried remove the red wire, it cannot run but the BEC was able to power up the Rx n Fan.

What "Red" wire u referring to? The o/p of ESC that connected to RX? or the "Red" wire going to your battery?

Since u remove the "Red" wire from ESC, everything is ok. Then definitely your ESC. If you referring to Red of o/p wire, then your ESC opto coupler maybe damage liau. (Shorted internally)

SH

[Adrianli]

The red wire refers to the ESC red wire to the rx.


Does an OPTO ESC require the red wire to be connected to activate it? I know the ESC wif built in BEC dont.

So tis ESC is still save to run wif 4 AA cells plugged into the rx???

[Super-Hornet]

Look closely on your ESC. Does your ESC has its own BEC (like LM7805) to power the internal circuitry of the ESC?

If yes, then heck care and remove the red wire.
If no, then u have to repair the ESC... or modify the ESC instead.
If not sure.. then u can try to see by complete disconnect the ESC to RX. Connect battery and hear whether the ESC got any beeping/musical sound or not. If not, then it does not have BEC for the internal circuitry.

SH

[ouan2308]

maybe u should look at ur BEC again .. although it is able to light up the LEDs, but LEDs draw very little current, compared against your RX and servos together ..

suggestion is to remove the connection of the ESC to your RX, and power your RX purely from the BEC w/o the servos first (hopefully your RX is those with at least a LED monitor to indicate that it is powered) ..

then plug in your servos (preferably only 1) and check the setup again .. if it does not work at all, use another confirmed working RX, still does not work .. BEC is the problem .. somehow, it cannot maintain her output at higher current draw ..

if using another RX works, then most likely your other RX is giving you the problem .. using your old setup, you have 2 power sources into your RX, 1 from the BEC and the other from the ESC .. most likly your "reverse current protection" on you RX has given way ..

anyway .. this should be worth a try .. will not take up alot of your time as well .. of course .. unless .. i have the picture totally screwed on me upside-down ..

[Adrianli]

Had already done that.

Connected BEC to Rx w/o ESC. Servo n Rx no problem at all. Tried on two other Rx also no problem at all. I believe its the ESC giving the problem. As both BEC no problem when connected to all Rx.


My boat only use one servo, so power consumption is very little only.