Been having some trouble with voltage to my reciever dropping when I connect a servo. This could be a result of some form of interference, or simply too much current (seems more likely)....
So, that would (in my case) mean a current drain 0.5A for a servo.....is that reasonable?
Servos can pull massive amounts of current for their size. It depends on the particular servo and what stress its under but for something like a futaba s3003 or a multiplex mx-6 or a simular standard servos its not uncommon to see them pull more than an amp from the receiver if under pressure to do something i.e. if trying to push a stiff lever etc.
ouch.....but my servo is for the moment unloaded...though it is a multiplex.
I used to get the same problem years ago, esp if I was using a servo/switch for a weapon and speed controller. Try using a BEC
No dont!!!!!
Becs can do 1-2amp max they will just make the problem worse. Use 1 of the following
A proper 700mah or more Ni-cd AA cell 4.8v rx pack.
Failing that a Battery box with 4 duracell batteries in it.
The first is much better as will last longer but if all comes to all use some duracells.
Regards
Ian
Okay....a separate battery will be as a last resort only. I will rather make a proper regulator.
But what current should I build it for? (Using reciever and one standard servo that may be working at max) Is 1A enough? 3A? 5A?
Jonas.
Is the servo really essential? Could you not do it with a rc switcher. Yes I know they are more expensive than a servo however they are much better and wont break or throw off a servo horn in the middle of a fight.
I personally have 1 servo in my robot to fire my valve but it is on the top of the list of things to be replaced.
But if you really cant then go for a Rx battery. Paul Hill one of the resident Techys (people who really know their stuff) is really strongly against regulators. They cause huge amounts of interference even with supression. But if you really have to go with something like a 5amp one. That should give you some spare just incase the servo stalls.
Regards
Ian
There are versions of the common 7805 that can supply up to 3A. If your main battery got a nominal voltage higher then 24V you should make the regulation in two steps. A normal ELFA73-095-60 should do the work. It can supply 2A.
There are drawbacks with common BECs. The most noticeable is the radio interference. At 1A and 24V input the loss is about 20W. It will require a rather large heatsink. Hopefully the average current is much lower then 1A.
Have Fun
STB
The reason for using somthing like a servo is to make a separate, fool-proof, safety system...the thought that servos would easily fail had not crossed my mind. I will look into building another interface.
If not, I have got hold of a switching regulator, will refit it for 36V, and test it later....
You are trusting to luck if you use a BEC. I have a web page all about them here: http://homepages.which.net/~paul.hills/Emc/Bec.htmlhttp://homepages.which.net/~paul.hills/Emc/Bec.html. That page also has a section showing how to use a rechargeable battery that can be charged from the main battery when not in fighting mode.
Good luck!
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