A/V multiplexor - Design Question 1

[rjgoebel]

Maybe something like this already exists, but I am trying to help my grandfather out in hooking up his brand new DVD player and the VCR to the TV at the same time. The inputs in the backs of the devices don't allow for it.

And I realize that we might be able to just return the player, but I thought this might be fun to build.

So my idea is to build a really simple multiplexor (not digital, just using a switch) to switch between the 3 connection VCR A/V, and the 3 connection DVD A/V signal that goes to the back of the TV. I just want a toggle switch or something that allows for my grandfather to walk over to the TV area and flick a switch if he wants to switch from DVD to VCR input to TV.

However, are there devices that allow you to control 3 switches with one mechanical motion?

 

[gcaudill]

You could use any brand of two-position, maintained, selecter switch with three contact blocks containg one Normally-Open and Normally-Closed contact per block. For appearance, mount the switch in a small and cheap enclosure available from the likes of Allied or Newark electronics. For cable interface go to RadioShack and buy component A/V plugs. This would make for a nice Saturday afternoon with grandfather.

 

[IRstuff]

Still should not be a problem.

You can usuall daisy chain such devices by connecting the DVD player to one of the inputs for the VCR and the VCR to the TV.

TTFN

 

[Skogsgurra]

My grandson helped me (one of the world's smartest guys!) hook up the DVD to my TV/VCR combination. I have no idea how he made it, but no switches were involved. Just the standard cables.

I guess that the instructions manuals are quite useful - if you understand what they say. And if you do not use your engineering knowledge. ;-)

Gunnar Englund

http://www.gke.org

 

[tuned99]

Is there any reason why you wouldn't want to get a premade one like this?

http://www.radioshack.com/product.a..._name=CTLG_003_010_011_000&product_id=15-1982

 

[rjgoebel]

That radio shack device will do the trick. I'm going to remove the cover to see exactly how it is set up, but that's exactly what I was going after.

Jim Goebel,
Electrical Engineer
Mid-West Forensics, Inc.

 

[VEBill]

Daisy chaining a DVD player through a VCR to the TV will often cause picture quality issues (shifting colour bands) caused by the annoying Macrovision 'copy protection' (sic) system. Basically, the VCR can't handle the Macrovision (which is the entire point I suppose...).

Some people might assume that the VCR's A/V circuits are bypassed in certain modes - they typically are not.

This Macrovision issue wouldn't show up just examining the DVD player's menu screens. You need to play a Macrovision protected (sic) DVD and see if the picture appears distorted.


The A/V switches are typically better value at Game Stores (places that sell PlayStations and similar gear). A very nice four input A/V switch might be US$12 or so. YMMV.