On 3/21/2011 12:17 PM, Smitty Two wrote:
In article
,
Harry wrote:


For what it's worth, my liftmaster has an "intelligent" button. It
connects with just 2 wires that power it and it sends signals back
down the two wires on top of the power to the controller to raise and
lower the door, to lock the door, and to activate the light. So no
ordinary push button is going to work on mine. Just saying there are
others out there.- Hide quoted text -

- Show quoted text -

Ya, riiightt. You can test that theory by disconnect the wires at the
switch and touching them together. Prepare to be embarrassed.

Harry K

You and Tony have both scoffed at James' post, but I see nothing wrong
with it. Haven't seen such a gadget, but it'd be duck soup to make a
control panel that has multiple buttons for different functions, still
with only two wires connecting the control to the operator head. Each
button sends a coded signal down the power wires, said signal being
demodulated at the far end.

Yes, very similiar to an automotive steering wheel. Just think of all
those different buttons on there and then imagine that there's most
likely only 3 wires doing all that.

--
Steve Barker
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