Y connections between servos

[Derek Warner]

on Tuesday, October 15, 2002 9:15 AM, Brett Hallet - dragoncity@origin.net.au wrote
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
This servo was 'Y' leaded to the rudder servo channel and therfoe moved automatically> snip
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Brett - you also made mention to Y connectioned servos for PS Industry - I understand series
& parellel connection, but am a little lost with Y connection - is it to drive two servo's in opposite
directions from the one signal??? - so could you please share this with us - regards Derek

[mstecker2002]

Derek:

A Y-connector for a servo can be bought at most hobby shops. It has one
connector from the receiver linked to two connectors to two separate servos.
The wire linkage is therefore shaped like the letter Y. Thus when your
transmitter sends out a signal it operates two servos simultaneously. With
airplanes I have used Y-connectors to operate two servos simultaneously.
For instance in large airplanes where increased thrust on the control
surfaces is desirable, it is better to use two servos instead of one to
operate the ailerons -- one servo to the right aileron and another one to
the left. In Brett's example a signal to the rudder servo will also
activate a second servo to move a weight to help the boat maneuver better in
the turns. By the way, what is PS industry? In my area of expertise the
letters PS stand for (Adobe) PhotoShop.


Michael Stecker

[dragoncity]

Derek,

After I replied to the query about 'Y' leads, I had forgotten
to mention as special Y lead that one can make to
connect two (2) batteries into one (1) input lead to your
reciever.

This is very useful if you wish to run two batteries for longer radio time
or in the case of aircraft a instant battery backup should one fail.

( after Pilot BRAIN failure, flat battery ( flat = another Pilot BRAIN failure :-)
are the most often causes of plane crashes )

What you do is take a standard servo 'Y' lead, and in EACH lead ABOVE the
'Y' you solder a diode ( its size will depend upon your battery voltage)
into the negative power lead. You may remove the control lead if you wish as its not used.

The diode only allows current to flow ONE way , therefore neither battery will affect
the other if they become 'unbalanced', ie: the more fully charged battery will not try to
charge the lower one and all power will go to the receiver.

Cheers,
Brett

[Derek Warner]

Thanks Brett - I have left you previous message intact - I have zero previous experience with aero models so all this
is very interesting [however I would have thought it be termed as parallel connection]

With Decoy using the old Futaba digital FP-MC5 speed controller, the documentation tells me the Rx battery is not
required with the RX getting internal supply from the speed controller, which gets its supply from the main battery

Now I am sure I have mentioned my understanding of electrical signals is somewhat lacking and the following confirms
this - the RX [upon request] sends an electrical potential [voltage] to turn the servo motor - yes I grasp this OK

But there are only three wires from the speed controller to the RX, so I assume the red = positive , and the black
= negative & yes I also grasp this OK, so how does the Rx send the signal back to the speed controller to control
motor speed?

Or is someone going to come back & say that the signal is sent to the speed controller in a modulated format via
the white wire???

I understand it works in it's bulkier cousin "hydraulic fluid systems" - but not sure with electrics - regards Derek