Archived from groups: alt.video.satellite.mpeg-dvb (More info?
> Gary J. Tait wrote:
>>On Thu, 14 Oct 2004 08:51:39 -0500, Matt Scoff <firstname.lastname@example.org> wrote:
>>>Is the DPDT automatic/self switching when the power on the Pansat is
>>>turned on or is this a manual switch?
>>You can di it either. Don't know what it would take exatly to make it
>>>>You could use a DPDT switch or relay arrangement to swap the
>>>>polarity control from one receiver to another. You need to switch
>>>>the +5V and skew lines, while the ground line can be in common.
>>>>The relay can be powered by the Pansat's 12V output, which you can program
>>>>to turn on when the receiver is on. This makes polarity control
>>>>automatic (just turn off the Pansat to switch over to the 922).
> Sears Canada has a switching gizmo that might be just what you are looking
> for. It has two receptacles set up so that when the device plugged into the
> primary receptacle is turned on, the secondary also turns on. I 'doctored'
> it for a guy by taking the relay inside apart and switched it from 'NO' to
> 'NC' (or the other way around. I can't remember.), so now the secondary is
> normally on, but if the primary is turned on, the secondary turns /off/.
> Sorry, but I can't remember the make or model of it - I altered it for him
> more than 3 years ago, but they /should/ still make them.
> Thnik about it!
That really is more complicated than you need.
A single DPDT relay and some wire will do the trick.
The relay needs to have a 12V coil. This one will do the job:
Here's how to wire it up:
A. Connect the following together:
- 1. one side of the relay coil (terminal 7 in the wiring diagram).
- 2. the ground of the Pansat.
- 3. the ground of the C-band receiver.
- 4. the ground of the servo.
- 1. the other side of the relay coil (terminal 8).
- 2. the +12V output of the Pansat.
- 1. one relay middle contact (terminal 5).
- 2. the +5V wire to the servo.
- 1. the normally-closed contact for the same side (terminal 1, I think).
- 2. the +5V output of the C-band receiver.
- 1. the normally-open contact for the same side (terminal 3, I think).
- 2. the +5V output of the Pansat.
- 1. the other relay middle contact (terminal 6).
- 2. the pulse wire to the servo.
- 1. the normally-closed contact for the same side (terminal 2, I think).
- 2. the pulse output of the C-band receiver.
- 1. the normally-open contact for the same side (terminal 4, I think).
- 2. the pulse output of the Pansat.
If you get some crimp-on quick-disconnect connectors of the appropriate size,
this will make the wiring quite easy.
I had some trouble reading the wiring diagram for the relay, since the scan
was pretty bad, so if I got the normally-open and normally-closed contacts
reversed, you may need to swap them.
In any case, you also need to go into the Pansat's LNB setup menu and
enable the +12V switch option for your LNB. This is not the same thing
as the LNB power option. Normally, the +12V option is used to turn on
a A/B switch for when you've got more than 1 LNB going into the receiver.
In fact, you can buy a +12V LNB switch and use it for this purpose as
well. The Dish Network SW-AJ works fine for this purpose, assuming you
can fine one anymore.
The net result of all that wiring is that the servo is normally connected
to the C-band receiver, until you turn on the Pansat. Then the servo is
connected to the Pansat receiver (until you turn it off).