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Old 05-08-2012, 07:23 PM
JensR JensR is offline
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Join Date: May 2011
Location: Bath, UK
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Default Re: how to change controls on Spektrum DX6i?

Hi Travis!

> On an ESC if you don't cut the signal it will always be able to work regardless of what you do with the power or ground in the lead going to the receiver since the ESC gets it's power from the battery connected to it.

For an ESC, cutting the ground has the same effect as cutting the signal, as the signal uses the same ground.
So, because ground is common, you only need one cheap switch instead of multiple expensive ones, plus you can combine servos and ESCs:

Most digital servos have some kind of fail safe - the cheap ones "just" actively stay where they are, the better ones can be programmed. Analogue servos will have no holding force if you cut signal.
Neither type of servo will have holding power if you cut plus or ground.
So, if you _do_ need holding force with your servo, you must use a digital one and you must cut the signal and only the signal.
But if you do _not_ need holding force, you can use any kind of servo and you can cut ground and hence you can combine those servos with ESCs.

BTW, the switches you suggest are oversized for this application with their 8A relay. If you are cutting the signal we are talking microA.
When switching the ground, we would probably not switch at full load, but the switch would need to be able to withstand the full load once switched. But one $5 miniservo and one $2 mini-toggle-switch would do the trick.
There might be miniature electronic switches that can be used if we only switch the signal - I do not know.

$80 buys you a complete 7.5 channel radio (Turnigy 9x) as such I'd aim for a lower cost alternative.

BTW2: If you operate multiple ESCs, you could instead switch the motor leads. This allows you to use fewer ESCs - which can be a very cost-effective solution.

Cheers
Jens
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