RC Power supply

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Revision as of 19:53, 11 December 2013 by Shornstein (talk | contribs)
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When using Futaba BLS 451 servos for example these are very modest. Savox 1258/Align DS610 are much more demanding, one alone taking up to 15Amps peak for the instance of a second. And for very extreme example take high voltage Savox servos SB-2271SG HV. They demand up to 27Amps (1 Servo!) peak which you can see when measure the power consumption with an oscilloscope.

So besides using a good stable and high rated power supply you have to ensure proper supply of the servos with this power. When only connecting one servo plug with power into the receiver, then this will produce a bottle neck. Additionaly the current taking a long way through the receiver, the wiring and the Microbeast will produce high resistance due to the connections in between and therefor loss of voltage.

For example when using the Align RCE-B6x BEC this only has one tiny power wire which is definitely not enough and we already had some people loosing power in flight and crash due to this, although this BEC unit itself can handle peaks of 20-25A without any issue.

So the least thing that is highly recommended with 50 size helis and larger is to use wiring with large diameter from the power supply and try to connect the power as close to the servo connectors as possible. The conductor track inside the MICROBEAST unit can even handle 60 Amps before it starts to burn out. It's layout is very beefy so as said the problem lays outside and is about getting the current over those standard type servo plugs which only can handle 2-3Amps continous.

So it is a good practice to use at least 2 or 3 power connectors, plugging them in parallel on all available free connections, like BAT port and free channel ports on the receiver and [SYS] port on the Microbeast. Then you should be safe.


External servo power connection

On the other hand it is a very good practice, when using such high power servos as mentiond above, to decouple the servo power completely from receiver and microbeast and use a regulator as power supply or some kind of power bus/power distribution system (which simply may be connecting the power wires from the servos directly to the battery). So voltage loss and internal resistance are reduced to a minimum (the higher the current and the higher resistance, the more voltage you will loose!).