servos voltage question
10-25-2012, 09:40 AM
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servos voltage question
Hello.
I'm new to RC. I'm upgrading myplane to brushless, so I'm getting new motor, ESC, and new servos to replace a dead one. I understand that ESC willpower my servos.Is this particularESC (http://www.hobbyking.com/hobbyking/s...dProduct=18004) going to work with this particular servo ( http://www.hobbyking.com/hobbyking/s...idProduct=7472)?
Thank you.
10-25-2012, 10:08 AM
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RE: servos voltage question
The ESC will provides at 5 vdc output to run the servos and RX. This is the typical voltage for most serovs so voltage should not be a problem. The important question to answer is can the ESC/BEC provide enough current for your system
The Hobby King ESC spec says the Bec part of it can supply 2 amps. This is on the minimum size/capacity. The servo info says nothing about current draw.
Also you do not say how many servos you have on your plane and what size/type of plane it is. Most basic BECs say they can handle maybe 4 analog servos and less digital ones.
If you have more than 3 to 4 servos you might want to consider adding a seperate BEC to your system than can proivde more amps out and drive more servos.
You might want to take a look at ESC and CCBEC info on the Castle web site for examples to see the capabilites of typical ESCs.
Also maybe look at the HitecRCD website and see their servo catalog and specs that will give you a feel for current loads of different type servos. Also Servo City has lots of info on many servo brands...Futaba and Hitec at least.
Good luck!
Jim D
The Hobby King ESC spec says the Bec part of it can supply 2 amps. This is on the minimum size/capacity. The servo info says nothing about current draw.
Also you do not say how many servos you have on your plane and what size/type of plane it is. Most basic BECs say they can handle maybe 4 analog servos and less digital ones.
If you have more than 3 to 4 servos you might want to consider adding a seperate BEC to your system than can proivde more amps out and drive more servos.
You might want to take a look at ESC and CCBEC info on the Castle web site for examples to see the capabilites of typical ESCs.
Also maybe look at the HitecRCD website and see their servo catalog and specs that will give you a feel for current loads of different type servos. Also Servo City has lots of info on many servo brands...Futaba and Hitec at least.
Good luck!
Jim D
10-27-2012, 12:36 AM
#4
Senior Member
RE: servos voltage question
The servo you noted is rated at 6v, and analog, so 2 to 3A should be enough.
If you can run the RX at 6v, and take advantage of the servos higher speed at 6v, the below may be of interest.
http://www.hobbyking.com/hobbyking/s...for_Lipo_.html.
If you go this route, remember to disconnect the red lead from the speed control at the receiver connector.
(Usually, this involves using a pin to help remove the red lead connector pin, folding the wire back, and insulating the pin.)
I found that with 6 analog servos, 2A is not enough peak current.
Last evening, I was checking servos and electronics on a 40 size warbird. The elevator servo seemed a bit wonky,
so I checked the current draw at 6v. It was pulling down the four AA carbon cell pack I use for testing to below 6v,
and pulling about 1 1/2 A ! New servo time!
If you can run the RX at 6v, and take advantage of the servos higher speed at 6v, the below may be of interest.
http://www.hobbyking.com/hobbyking/s...for_Lipo_.html.
If you go this route, remember to disconnect the red lead from the speed control at the receiver connector.
(Usually, this involves using a pin to help remove the red lead connector pin, folding the wire back, and insulating the pin.)
I found that with 6 analog servos, 2A is not enough peak current.
Last evening, I was checking servos and electronics on a 40 size warbird. The elevator servo seemed a bit wonky,
so I checked the current draw at 6v. It was pulling down the four AA carbon cell pack I use for testing to below 6v,
and pulling about 1 1/2 A ! New servo time!
10-27-2012, 05:46 AM
#5
RE: servos voltage question
Horizon sells a little battery checker which plugs into a batter y and you can try loads - up to 2 amps
Using new , well cycled, fully charged 1900ma ENELOOPS in a four cell pack- - 2 amps pull voltage from 5.5 to 3. 8
Anytime you see a voltage depression of over one volt - look out !
As a comparison- a two cell 1100 ma A123 pack -not freshly charged (Ihave a bunch of em ) tested with a 2 amp load - shos typically 6.6 volts -dropping to 6 .3 volts
The point being that amp ratings on cells means little - It is the amps under load which is really the issue
Any time I see the comment that the plane flew for 4 minutes - then the rx failed - I strongly suspet the failure was NOT the rx.
Using new , well cycled, fully charged 1900ma ENELOOPS in a four cell pack- - 2 amps pull voltage from 5.5 to 3. 8
Anytime you see a voltage depression of over one volt - look out !
As a comparison- a two cell 1100 ma A123 pack -not freshly charged (Ihave a bunch of em ) tested with a 2 amp load - shos typically 6.6 volts -dropping to 6 .3 volts
The point being that amp ratings on cells means little - It is the amps under load which is really the issue
Any time I see the comment that the plane flew for 4 minutes - then the rx failed - I strongly suspet the failure was NOT the rx.
