BEC - Switch mode

Sorry I can't remember (or find) the colleague  who recommended these.

I have tried one in my Pioneer sub (admittedly on 458 Mhz where noise and glitches are generally no problem) on several occasions and it works fine. It may have changed my generally negative view of noise from switch mode power supplies. (I have ordered another couple.)



Sellers Specification:

Brand new
Size: approx. 42*24*11mm

Output Voltage: 5V or 6V (Changeable with an output-voltage select switch)

Continuous Output Current: 3 Amps

Input: 5.5V-26V (2-6 cells lithium battery pack or 5-18 cells NiMh /NiCd battery)

Fine workmanship and good performance.

Easy to use.

Long service life.



Package included:

1 x 3A RC UBEC Switch

I have never had any Issues with them but i have never done any tests for noise. I assume these work so well because they have shielding, its not just a bare PCB.

I do like these. Now tried in all my subs. Neat and very small (and not expensive!)
Two more on order.

David

Slight modification to my overall recommendation.
I have just gone back to a linear BEC for my Nautilus 2 model. This uses hefty motors driving sail winches. This seemed to give voltage drops which caused the Arduino in the winches to Reset. I tried including a large electrolytic to buffer these voltage swings but it didn't solve the problem.

I would use a pair If that is happening. One for the winches and another for the rest of the system. I have a pair on my tug. One at 5v for rc electronics and one at 6v running my sound, smoke lights Winches etc. Since the little oil smokers can pull over an amp each they just overload the main bec if I try and run them with it.

I use two BECs in my sailboats... primarily so that i can run the sail winch servos at a higher voltage than the rest of the system, and secondly, it is a large 20 amp capacity switching BEC because of the reasons already listed... huge amp draw possible when all servos are under load.

Using 2 BECs sounds like a very good idea. Thanks I will give that a go.
(Linear BECs are so inefficient unless you want a warm WTC !)

David

Edit 2 hours later. That idea works well on the bench. Thanks Both!
Three more switch mode BECs on order.

Surely this is a silly question, but since ESCs turned up I've always powered my radios from the built in BEC in my speed control.
The ESC I'm looking at doesn't actually have any option to disable BEC.
I assume you can have multiple, assuming they all push the same dc voltage onto the rail?

cat wrote:Surely this is a silly question, but since ESCs turned up I've always powered my radios from the built in BEC in my speed control.
The ESC I'm looking at doesn't actually have any option to disable BEC.
I assume you can have multiple, assuming they all push the same dc voltage onto the rail?

You can just disconnect the centre pin from the ESC servo plug if you want to stop its 5v regulator powering anything.

Running more than one is generally fine they will almost always have diode on the output so what will happen is the regulator with the highest voltage will take most of the load, then that load will get distributed as the voltage falls between the rest in order of voltage. the problem is most escs have a linier regulars so what will happen is one will overheat trying to run everything.

It's better to split the 5v system, with your critical items split from the high loads with independent regulators.

i use external BECs because the BEC built into most ESCs is good for only one or two normal size servos.  so, if you have rudder/rear plane/fwd plane, the BEC is probably already not happy, add a pitch controller, a high torque or high voltage servo into the mix, and now your ESC's BEC is really out of its comfort zone.

Right, I get you, move too many servos at once and the current draw is going to get the little regulator in the ESC all sad and sagging.
I'm unused to anything needing more than two or maybe three servos so this explains my ignorance. being thick explains the rest :D

Those 2 BECs worked very nicely  in the model this Sunday.
Thanks for  the suggestion, Chaps!

Update over here:

https://www.theassociationofmodelsubmariners.com/t1955-nautilus-ii-by-robert-fulton#12551