Possible to modify a WalMart audio/video selector?

[Doc]

I'd like to modify one of these A/V selectors like you find at WalMart
- has 4 in & 1 out plus a 1/8" stereo headphone out jack, and rewire
it so that there are 3 in & *2* outs that you can switch between.

I opened one up and find there are 3 sections of circuit board, and
the switching is accomplished with this spring loaded catch mechanism.
There are various places where pieces are hot-glued together.

Anyone ever done something like this?

 

[William Sommerwerck]

I see a number of problems.

The cheapest way to manufacture such a device is with single-throw switches.
That is, pressing a switch doesn't disconnect anything. Rather, it simply
connects the selected input to the output jacks. The previously selected
input is disconnected by the mechanical interlock that releases the
previously pressed switch. If you forced down two or more input switches,
all their signals would be connected to the output.

Unfortunately, switching the selected input _between_ two outputs requires a
double-throw switch. And I would bet my life that this unit doesn't contain
any.

There is also the fact that the board is hard-wired, and trace-cutting and
re-routing will be needed.

I'd suggest this... Buy two of these switches. Connect their _outputs_ (yes,
their outputs) together. You then connect the program sources to the inputs
of one of them, and the monitors, etc, to the inputs of the other. Select
the input on the first, then the display on the second. Easy as eating pie.
Four inputs on one, four displays on the other. Any one to any other one.

QED.

I'm waiting to hear people argue about this.

 

[Doc]

I'd suggest this... Buy two of these switches. Connect their _outputs_ (yes,
their outputs) together. You then connect the program sources to the inputs
of one of them, and the monitors, etc, to the inputs of the other. Select
the input on the first, then the display on the second. Easy as eating pie..
Four inputs on one, four displays on the other. Any one to any other one.

Interesting and potentially useful. Part of my goal for my immediate
purposes was to avoid having to get another one, and also just as an
experiment. My initial examination made me think it wouldn't be a
simple matter but I don't have a lot of experience. The first thing
that struck me is that things just aren't very accessible the way
they're built and would require a *lot* of desoldering just to
separate the pieces to get a clear view and clear access and then try
to figure out what's routed where and how to change the course of the
river.

At times I've used them in reverse, using the out's as in's since it's
nothing but pathways.

 

[[email protected]]

I'm waiting to hear people argue about this.

Would be more likely with more eyes seeing it. Wondering why you
stripped out the other groups to which this is a relevant topic? I
assume the Google/Usenet gods made it possible to x-post because they
felt there was a valid reason to do so.

 

[William Sommerwerck]

Would be more likely with more eyes seeing it. Wondering why
you stripped out the other groups to which this is a relevant topic?
I assume the Google/Usenet gods made it possible to x-post
because they felt there was a valid reason to do so.

Technically, it's relevant only to the original poster. Anyhow, people are
always griping about cross posts, so I stripped the others.

 

[William Sommerwerck]

Interesting and potentially useful. Part of my goal for my immediate
purposes was to avoid having to get another one, and also just as
an experiment. My initial examination made me think it wouldn't be
a simple matter but I don't have a lot of experience. The first thing
that struck me is that things just aren't very accessible the way
they're built and would require a *lot* of desoldering just to separate
the pieces to get a clear view and clear access and then try to
figure out what's routed where and how to change the course of the
river.

At times I've used them in reverse, using the out's as in's since it's
nothing but pathways.

That's it. You got it.