External BEC for Esky ESC & AR6200

[nas_matko]

Finally my TX (DX7) and RX have arrived so I am going to set everything up and hope for the best. However, being grounded for so long I was reading, reading and reading and I came across this article:

FAQ (http://www.dimensionengineering.com/BECFAQ.htm) from company Dimension engineering saying that
Some of the new Spektrum receivers draw significantly more current than a normal receiver, and are particularly sensitive to voltage fluctuations. An external switching BEC can help ensure your new receiver gets reliably powered.

Has anybody ever had power issue with Ar6200 or 7000?
Should I buy external BEC (e.g. http://www.dimensionengineering.com/ParkBEC6v.htm) for my esky ESC?

[ranger306ci]

If you ae going to power more than 3 micro sevos, you need a seperate bec.

[nas_matko]

You always power more than three servos on heli, don't you?

[estarter]

I have 200+ flights using the Esky 25A esc and 6100, never cut off or glitches, this is with the stock Esky servos, 3100kv motor and 0704A gyro. No external BEC. Your mileage may vary. BTW, the magic smoke came out from the esc at around 25 flights later.

[ranger306ci]

Thats the problem, peoples mileage does vary. Some have better luck than others. Just to be on the safe side, I run a sep. bec on EVERYTHING with more than 3 servos, 72mhz or 2.4ghz. Add to the fact that it is more efficient( less electricity wasted as heat)

[estarter]

External BEC is cheap insurance. Check your servo/gyro voltage spec before going to 6V BEC.

[nas_matko]

Would 5V BEC be more universal solution?

[ranger306ci]

yep, it is fine.

[swatson144]

on 3S a linear BEC is marginal at best. you can get away with it and many do but LV switching becs (5S and less) are so small and cheap it seems silly not to have one installed before the really hot days arrive (much better chance of it going off on over temp).

Steve

[nas_matko]

Can you recommend resonable BEC? Any experience with Dimension Engineering?

[swatson144]

The park BEC line is good, don't let the 1.5A rating put you off as it is still more than a 3A linear has left after overhead. (Vin-Vout) * A =overhead watts, 15w - OHW = usable watts /5V = actual amperage. So if we assume a fresh lipo at 12.6v and a 1A load on the gear we get 12.6-5V = 7.6V * 1A = 7.6W. 5V*3A bec rating = 15W total - 7.6W overhead = 7.4W usable / 5V = 1.48A usable. That's roughly how a linear BEC works but will change with cooling and temperature. A 3A BEC is good for 15W total any more and it starts heating up. All of the regulator chips have built in thermal protection so when they reach that temp they shutoff until they cool down.

The switching BEC will supply it's rating at all reasonable ambient temps. Hobby city also has some I've been happy with for ~ 8$ https://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=4319 if you order 2 of them you can get them shipped for ~4$ and they'll be in hand by the time the temps are real bad.

Steve

[nas_matko]

Thanks Steve.