I fly my Jet (about 12 kgw) with 2 JR 8711 servos to control the elevon,one Futaba 9151 servo for rudder,other 2 stand servos for nose wheels steering and retract.The receiver is JR RS 10DS .Can the receiver stand so many servo output?How much is the largest current when JR 8711 servo works?How much current can the receiver stand?

Most if not all JR 10 channel Rx of the 1024 PCM will easily handle what you describe here. Just make sure you batteries can handle this load....

Here is a stupid Question. are the Amplifiers in the servos, or the Receiver?

The amps are in the servos. The receiver just furnishes the current path and the control pulses to the servos.

John S.

As a side note, when you talk current handling capability, you are talking ultimately about how much heat (that results from the resistance and the current flow) the system can handle.

So the amount of current that can be handled steady state through the pins, traces, connectors etc of the RX is different than the peak currents that can be handled for less than a second, say.

So anybody know the # of amps (continous)?

20 is the number as told by JR's John Redman. It is doubtful that any of us can get there. The limitation has always been and continues to be the molex connectors. Older style PC's (really old) use the same connectors on internal fans.

The limitations are the servo connectors..they are only rated for 3 amps each, even though some servos can suck 5 amps......

Thanks for all your answer.I understand my now installation is safe.I will pay more attention to the battery and switch.Thanks a lot again!

No one knows for sure. There has never been a published scientific test to find out the answer to this question. Some are educated guesses here, including mine[8D]. The key word here is "continuous"

Ehab, it was published here about a year ago by a Horizon Representative, the answer was 20 amps. The same Rep indicated that sometimes, a battery terminial would be welded to the receiver board because too many amps were pulledthrough the molex connector.

It's not any one servothat needs to be worried about, it's how many amps do you expect to pull, with safety margin, and is your electrical system as a whole designed to deal with that??

Can you get me the link to this test? I tried the search in this forum to no vail. I'd like to look at this data.

I just got back from getting certified in digital thermography...I'm curious as to what the thermal hot spots are on an RX with the RX under load...(Current = Heat)...I'm running 6 digital and three analog servos in my L-39 including two 8711's...And would like to look at the servo bus when under load...

Also, digital thermography is also useful in determining bad cells in a flight pack...Especially NiCads or NiMH batteries...Dead cells show up as cold cells and cells that have high internal resistance are naturally hot....Also, cell imbalance is easily detected using the same means...

Kevin