custom A/V switcher help
 

so I'm trying to wire up a custom video switcher for my car to do exactly what this does (only need video tho)


http://i10.photobucket.com/albums/a1...e8cc837375.jpg


here's the diagram that @MmmDieselFumes drew up a while back, but looking at it shouldn't +/- for each input be on the same relay and not 1 is all + and 1 is all -? just doesn't seem like it would work or it would try and activate half of each input this way


http://i10.photobucket.com/albums/a1...8_/Diagram.png

the diagram is correct. You want a separate relay for the negative wires and a separate relay for the positive. When the switch is turned one way it will activate the positive of video input one on one relay and negative for video input one on the other relay. When flipped the other way it will active the positive and negatives for the second video input.

ok cool thanks. also would these work for the inputs? can't find anything better or simpler

http://www.ambery.com/spwitorcaadk.html

You dont need to use relays.

You can simply just use a DPDT (Double pole Double throw) switch.

http://i1240.photobucket.com/albums/...ps38c9221b.png

If you can only get a SPST (Single Throw) switch you can connect the grounds (-) together and just switch the signal / (+)

Also, if you do use relays, make sure you use a power diode across the coil, when the power is released from the coil there is large back EMF ~200V that can do damage to the electronics

so this is what i need right? also not totally sure what wire would go where in this as i've never used one of these

Yep, this is the most straight forward way to do it

Here is a drawing ive done that shows the back of the DPDT Switch

RCA to HU = out to Head Unit
RCA A = Source 1 , eg camera 1
RCA B = Source 2 , eg camera 2

http://i1240.photobucket.com/albums/...ps962329a8.png

looks easy enough. and i need on/off or on/off/on?

this seems right if I'm not mistaken

http://www.ebay.com/itm/2-Pcs-Black-...item51b7f9ce87

Yep, that would work, you need on/off, but cutting out the rectangle for that size switch may be a hassle

I would use a smaller toggle switch, you only need to drill one hole, and the hole would be easy to cover up later down the track if you dont use the switch anymore

http://www.ebay.com/itm/5-x-AC-125V-...item484f938d32

well thats just an idea. i prefer the flat style like that but round. and i put my switches on the tiny removable piece thats connected to center console under inner knee pad (cheap replacement part)

Cool, post some pics once your done :thumbsup:

will do once i get all the parts. it's honestly already a completed project, i just wanna clean it up a bit

so i hit a snag. its all wired, feeds both work (tested it with my backup camera), but for some reason it won't read the input when i plug the SNES into it. tested SNES on laptop capture and the cable is fine. so the switcher reads backup camera fine, but won't read SNES. any ideas?