RC India

RC Equipments => Radios and Receivers => Topic started by: Swapnil on June 04, 2011, 10:14:31 AM



Title: Controlling two servos with same signal
Post by: Swapnil on June 04, 2011, 10:14:31 AM
A Tx usually comes with an Rx with more channels than the Tx. 
Can I drive 2 servos using 1 signal with the configuration shown in the following pic?
(so that each servo can have an independent source)


Title: Re: Controlling two servos with same signal
Post by: Swapnil on June 04, 2011, 10:16:36 AM
Here's the pic...


Title: Re: Controlling two servos with same signal
Post by: CrazyPilot on June 04, 2011, 10:27:54 AM
Any reason for not using Y cable?


Title: Re: Controlling two servos with same signal
Post by: Swapnil on June 04, 2011, 10:29:19 AM
Well, that loads a single channel, doesn't it?


Title: Re: Controlling two servos with same signal
Post by: AEROVISHWA on June 04, 2011, 10:45:56 AM
no it wont.... they are built for it..!! and more over you will be cutting the servo wire.. and if u wanna remove the servo in the near future will be a prob....

if you are keen on cost cutting preserve the things.. instead the above you can use a y- harness..


Title: Re: Controlling two servos with same signal
Post by: Swapnil on June 04, 2011, 10:50:30 AM
and more over you will be cutting the servo wire.. and if u wanna remove the servo in the near future will be a prob....

It can be done without hurting servo wires, but I suppose a y-harness would be a straightforward option...


Title: Re: Controlling two servos with same signal
Post by: AEROVISHWA on June 04, 2011, 11:15:48 AM
thats what i ment.... if u have a programmable radio u can use it too..!!


Title: Re: Controlling two servos with same signal
Post by: Swapnil on June 04, 2011, 11:20:18 AM
Yeah, well, I thought we could utilize an extra Rx channel this way.
But, say the servos in question are heavy duty ones (and not the regular 9gm ones), would this circuit be a better option (against a y-harness)?


Title: Re: Controlling two servos with same signal
Post by: AEROVISHWA on June 04, 2011, 11:25:30 AM
i was speaking about std servos not 9 gm ones....!!! if you have a programmable radio you can put 2 servos in two channels and link them by your radio...!!

the Rx can take the load of 2 servos in 1 channel.... more over i have seen multiple servos in one receiver channel in bigger planes which have 6 servos on alirons etc..!! :salute: :salute:


Title: Re: Controlling two servos with same signal
Post by: Swapnil on June 04, 2011, 11:27:28 AM
.... well, I thought we could utilize an extra Rx channel this way.

:)


Title: Re: Controlling two servos with same signal
Post by: ujjwaana on June 04, 2011, 11:36:43 AM
Well, that loads a single channel, doesn't it?
The shunt on the PWM single wire is minimal, and more than one servos (2-3 in practicality) can easily share without any Voltage Level loss. The concern should be more on power lines (+/-), but then the same parallel PCB track  feed all the channel.

if you are really bent on using different channel, then your Tx should support such  mixing. Advanced Radios like Futaba 12FG, 14MZ, Jr9 etc support such mixing, like that for multiple servo put on same control surface.


Title: Re: Controlling two servos with same signal
Post by: anwar on June 04, 2011, 11:44:10 AM
Plus, if you are worried about current draw, the solution is a power box.  But this is needed in really demanding situations, typically 50cc or higher planes.


Title: Re: Controlling two servos with same signal
Post by: SunLikeStar on June 04, 2011, 12:14:59 PM
This wont do any help as the power terminals on all channels are split from a common Vcc and Gnd.


Title: Re: Controlling two servos with same signal
Post by: Swapnil on June 04, 2011, 12:19:45 PM
This wont do any help as the power terminals on all channels are split from a common Vcc and Gnd.
Oh, got it finally! Thanks!