supplying servo power directly off a battery

[ferp420]

here's a link to a video about it
https://youtu.be/jrc2ZBnYYwU

and here's a link to a thread about this I don't know how much help it will be but it has pics of the wiring that might help
http://www.rccrawler.com/forum/electronics/630362-hh-shv650-servo-mamba-x-esc-issue.html

 

[Panther6834]

I suppose years back I'd just figure it out on my own.

But not so much these days.

I will admit, right now, I'm slightly confused. In your initial post, you stated the servo was a 3-wire servo, which would indicate it's designed to receive power from the Rx. However, the wording of your second post (post #3) is worded in such a way that it makes it seem you have a "direct power" servo...which would actually be a 4-wire servo (ie. + & - for power from battery going to one connector, and then a signal & - wire going to the JR connector for the Rx). Which is it? Maybe that's why our replies don't seem to be helping you - because, in your comments, you've actually referenced two completely different servo wiring configurations. From the beginning, it would have been helpful if you posted a photo of the servo, so that everyone attempting to help you would know what the actual servo is.

Sent from my SM-X818U using Tapatalk

 

[Ots]

I agree with Panther. There are several things in the first post that don't jive (12.6V and 4S? 12.6V is a fully charged 3S) and then talking about hooking up a three-wire servo. That's why I went on about RC car wiring 101 which wasn't what you wanted.

So can I ask a silly question? Why are you attempting to install a 12V direct powered servo? Is this for some special purpose? Maybe you answered that already - I didn't go back and read every word.

 

[ferp420]

I agree with Panther. There are several things in the first post that don't jive (12.6V and 4S? 12.6V is a fully charged 3S) and then talking about hooking up a three-wire servo. That's why I went on about RC car wiring 101 which wasn't what you wanted.

So can I ask a silly question? Why are you attempting to install a 12V direct powered servo? Is this for some special purpose? Maybe you answered that already - I didn't go back and read every word.

i think he sead he has a adjustable bec to keep his 12 consistant
not that it matters for wireing the servo

 

[TacoCrawler]

john from Holmes hobbies who pioneered the direct power servo did a write up on them and he telks about those adapters too and goes in to the who and why of it all
basically though the servo needs to be rewired to a 4 wire instead of a 3 wire
I have one like that a 3 wire 16.8v servo that I tried the adapter on and it glitched like mad the truck was un drivable works fine on 4.8v from the receiver but it's week lol so I'm gonna experiment with it and try running it with only the signal wire going to the rx if that doesn't work I'll try adding another ground wire if that still dosent work it will end up in a different rig maybe as a shift servo

you shouldn't need a ground to the rx if there is one from the servo to the battery in theory you can just run the signal wire to the rx like castle and hobby wing dose with there auxiliary wires but I haven't tried it yet I had planned too I can post up next week if it works I'll post in my 1/6 ranger build thread if that doesn't work you can try the hh adapter but those only work for some esc/radio combos

what brand servo are you running ?

I'm running a Chinese monster 1/5 scale servo pumping out 150+KG of torque. Not super fast, but it will break your arm ! Lol
I will likely discuss the workings with John when it arrives and if I can't figure it out on my own.
The Neg- and Pos+ are with the servo, fed into the RX.
But I will also need a ground for the power supply. (Lipo Battery)
That is why I needed to know if I could share the common ground from the servo's input at the RX. Maybe the by-pass does something different ?
I dunno, and it's likely I'll have to inquire with John on this when it arrives and I plan to install it. In the mean time I'm still hunting down some other stuff regarding. I've got to make sure I don't fry this "e" stuff during the hook up.
I'm sure I'll figure it out before attempting.
Already have the adjustable voltage regulators so that's out of the way.
So I'll be capable or running 7.4v to my LED lightbar and 12.6v to my steering servo. At least that's what I'll hope for 8)

 

[morgoth924]

The servo needs it's own neg to battery, otherwise all the current (I suppose a lot with 150 kg torque)would go through the small receiver contacts, they will not like that.

Verstuurd vanaf mijn SM-A600FN met Tapatalk

 

[TacoCrawler]

I will admit, right now, I'm slightly confused. In your initial post, you stated the servo was a 3-wire servo, which would indicate it's designed to receive power from the Rx. However, the wording of your second post (post #3) is worded in such a way that it makes it seem you have a "direct power" servo...which would actually be a 4-wire servo (ie. + & - for power from battery going to one connector, and then a signal & - wire going to the JR connector for the Rx). Which is it? Maybe that's why our replies don't seem to be helping you - because, in your comments, you've actually referenced two completely different servo wiring configurations. From the beginning, it would have been helpful if you posted a photo of the servo, so that everyone attempting to help you would know what the actual servo is.

Sent from my SM-X818U using Tapatalk

This is not a direct power servo. It does not have a power lead on it.
The fact is no RX can handle 12.6 volts run through it anyway.
That is why I need to utilize the HH's by-pass wiring.
I never mentioned a JR connector or plug. And if I did it was a typo error.
I did mention using JST plugs though !? But those were before I knew of this HH's by-pass method to/through the RX.
I will simply use the JST plugs to supply my voltage regulators with the necessary voltage for each component.
The servo does not have a name. It is an industrial servo mfg'd in China.
But if 150 KG can't turn these wheels ? I'd be shocked !
Granted I'm rolling near 50 LBS on this behemoth now ! Thanks to all these Vitavon alloy components I have on board.
It'll likely be closer to 60 lbs when I'm done.
So got to make it strong if I hope to keep it in one piece.
The Vitavon driveshafts weigh in at a tad over 1 lb by themselves !
This is not about the costs associated. But about doing it right from the start 8)

Sorry I didn't post pictures. I really don't have that tool these days.
Lost that ability when Photobucket tried to extort me ! And it's too late for me to start over

 

[TacoCrawler]

The servo needs it's own neg to battery, otherwise all the current (I suppose a lot with 150 kg torque)would go through the small receiver contacts, they will not like that.

Verstuurd vanaf mijn SM-A600FN met Tapatalk

I believe the HH's by-pass wiring supplies both the RX and the servo with a ground wire - & signal
Only difference is the POS + does not supply the RX with voltage.
The voltage only supplies the servo.

 

[TacoCrawler]

I agree with Panther. There are several things in the first post that don't jive (12.6V and 4S? 12.6V is a fully charged 3S) and then talking about hooking up a three-wire servo. That's why I went on about RC car wiring 101 which wasn't what you wanted.

So can I ask a silly question? Why are you attempting to install a 12V direct powered servo? Is this for some special purpose? Maybe you answered that already - I didn't go back and read every word.

No special reason I just want the servo at full potential.
BTW it's 12.6 volts not just 12v.

i think he sead he has a adjustable bec to keep his 12 consistant
not that it matters for wireing the servo

No special reason I just want the servo at full potential.
BTW it's 12.6 volts not just 12v.

i think he sead he has a adjustable bec to keep his 12 consistant
not that it matters for wireing the servo

that's 12.6 v mister ! Lol

But seriously why would it not matter ?
The 3s lipo would be starving this servo I'd think ?
As it loses voltage below 12 v ? But it could still lose peak function a 10. v

That's why I keep thinking about my 4s Lipos and those voltage regulators.
But 3s would be acceptable if it doesn't drop too much below 12. v
Though 11.40 would seem fairly low on voltage ?
If it does I won't receive the max potential of this servo I'd think !?
And could even cause glitching at lower voltages I think ?

I'm going to need to rethink my servo requirements so that I can run my 3s Lipos without issue.
Think we already had this discussion once before. Dejavu?

 

[Panther6834]

And, still, the Op posts no photo, so no one has any real clue what the Op is referring to. Just continues to provide a bunch of nonsense (such as stating he never said anything about a JR connector, only it having a JST connector...except that a JR connector is what gets plugged into the Rx).

Unsubscribing.


~ More peace, love, laughter, & kindness would make the world a MUCH better place

 

[ferp420]

your over thinking it ive got 10 or 15 of these direct power servos some have 3 wires with a adaptor most have 4 wire
i have some 16v servos oh thats 16.8v if you really want to get down to it or a 4s capable servo that came with 3 wires and i am runing it off of 4.8v right now with out issue so as long as you dont over volt the servo you should be fine
oh and radio link radios claim 8s opetating voltage on some recivers but claim 12v on there reguler recivers probably how they get that crazy range with there dirt cheap radios
and im sure other radios use 12v capable recivers
12v lol like a car is 12v but really runs off of 14.6v or more that the alternator puts out

 

[TacoCrawler]

And, still, the Op posts no photo, so no one has any real clue what the Op is referring to. Just continues to provide a bunch of nonsense (such as stating he never said anything about a JR connector, only it having a JST connector...except that a JR connector is what gets plugged into the Rx).

Unsubscribing.


~ More peace, love, laughter, & kindness would make the world a MUCH better place

https://www.ebay.com/itm/403983536423?var=673864822846

Besides links that's the best I can do https://www.ebay.com/itm/284633094288

https://holmeshobbies.com/wiring-an...-rx-bypass-adapter-with-auxiliary-output.html

I'm not that adept to this modern world.

 

[TacoCrawler]

your over thinking it ive got 10 or 15 of these direct power servos some have 3 wires with a adaptor most have 4 wire
i have some 16v servos oh thats 16.8v if you really want to get down to it or a 4s capable servo that came with 3 wires and i am runing it off of 4.8v right now with out issue so as long as you dont over volt the servo you should be fine
oh and radio link radios claim 8s opetating voltage on some recivers but claim 12v on there reguler recivers probably how they get that crazy range with there dirt cheap radios
and im sure other radios use 12v capable recivers
12v lol like a car is 12v but really runs off of 14.6v or more that the alternator puts out

But I would think if you under volt that servo it will not obtain its full potential/specifications ?
(And this servo needs to be run at 100 %, promise !).
I have never heard of an RX that can handle 12. V in the RC car industry.
If you can find one and it can be bound to my RTR Spectrum or a FS GT5 I'd probably want to buy one :wink:

I probably should just purchase a lower voltage servo that I can run through my stock RX BEC voltage. But those likely cost 5 X's as much !?

I'm not ponying up for a Beast 2000. I'd rather just keep the stock RTR POS servo. So far the stock servo has held up !? But it required that I spend a small fortune on upgrading that panhard link mounting with 7075 alloy.
And even then it will still likely fail. Besides it's weak sauce regardless of what one does to improve its longevity.