Retract Servo Separate Battery pack ground question
07-15-2011, 12:24 AM
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Retract Servo Separate Battery pack ground question
Is it ok to use different size battery packs for retracts and receiver when running a setup where the retracts have their own power supply? For example, a 4.8V Nicd retract battery and a 6V Nimh receiver pack.
If you look at the diagram below, it looks like both battery packs have a common ground. Yes I understand the positive wire for the retract is connected only to the retract battery, but there is a path for current to flow from one pack to the other through the negative wires.
Normally this would not occur due to internal resistance in the servo itself, but what if the servo is stalled due to a jammed landing gear leg - and stays stalled for the duration of the flight, approx 10 minutes.
Would the heat build up lead to an internal short in the servo from the red to black wire? The current would then seek the path of least resistance and start flowing from the larger pack to the smaller one through the retract servo. So it's like there would be 2 battery packs of different voltages connected in parallel through the retract servo.
Any thoughts, plausible scenario?
If you look at the diagram below, it looks like both battery packs have a common ground. Yes I understand the positive wire for the retract is connected only to the retract battery, but there is a path for current to flow from one pack to the other through the negative wires.
Normally this would not occur due to internal resistance in the servo itself, but what if the servo is stalled due to a jammed landing gear leg - and stays stalled for the duration of the flight, approx 10 minutes.
Would the heat build up lead to an internal short in the servo from the red to black wire? The current would then seek the path of least resistance and start flowing from the larger pack to the smaller one through the retract servo. So it's like there would be 2 battery packs of different voltages connected in parallel through the retract servo.
Any thoughts, plausible scenario?
07-15-2011, 02:58 AM
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RE: Retract Servo Separate Battery pack ground question
No....the receiver is bussed together for power...the way you have the drawing would put a 6V and a 4.8V battery in parallel....
07-15-2011, 03:12 AM
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RE: Retract Servo Separate Battery pack ground question
scooty
your diagram is correct
you do want the "Y" between the Rx and the Retract servo,, then cut the red wire coming from the RX before the "Y",, you need to have the Ground and the Signal wire from the RX only
Why you want to do this in the first place is a ?,, you have a binding problem or are you trying to slow down the retract servo??
your diagram is correct
you do want the "Y" between the Rx and the Retract servo,, then cut the red wire coming from the RX before the "Y",, you need to have the Ground and the Signal wire from the RX only
Why you want to do this in the first place is a ?,, you have a binding problem or are you trying to slow down the retract servo??
07-15-2011, 05:18 AM
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RE: Retract Servo Separate Battery pack ground question
ORIGINAL: dasintex
Your right, the red wire is cut in the wromg place on his diagram, the 2nd diagram is correct, I used this diagra on one of my set ups that had mechanical servo operated retracts; works great.
Your right, the red wire is cut in the wromg place on his diagram, the 2nd diagram is correct, I used this diagra on one of my set ups that had mechanical servo operated retracts; works great.
07-15-2011, 08:07 AM
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RE: Retract Servo Separate Battery pack ground question
ORIGINAL: dasintex
you are correct, I read it wrong, that is why I deleted my post.
you are correct, I read it wrong, that is why I deleted my post.
Whoops! Guess I quoted as you deleted! sorry
07-15-2011, 08:53 AM
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RE: Retract Servo Separate Battery pack ground question
ORIGINAL: exeter_acres
Whoops! Guess I quoted as you deleted! sorry
ORIGINAL: dasintex
you are correct, I read it wrong, that is why I deleted my post.
you are correct, I read it wrong, that is why I deleted my post.
Whoops! Guess I quoted as you deleted! sorry
