OT- Anyone here familiar with security camera internal wiring ?

http://www.specotech.com/index.php/products/video/cameras/analog?format=raw&task=download&fid=55

The video cam inside the housing has only 3 wires, red, black and yellow. What I need to know is the yellow wire for absolute sure the signal wire ? Besides the color standards, internally the red and black wires double up such that half go the the LED lights and half go to the camera board. The yellow wire exits the camera board only.

The reason I want to know this is I want to connect a separate 12 volt source to the 12 volt camera input and then connect the signal wire to a rather expensive marine multifunction screen to see if the signal wiring is still connected at that point. But it might be rather problematic if I fed 12 volts into what is mean to receive signal info only.

I called Specotech but they won't talk to anyone about things like this unless you have an "industry professional" pin number !

I found quite a few pages showing the user manual for this camera, but this is the only page which shows the wiring diagram.

https://www.google.com/search?num=1....12.0....0...1c.1.64.serp..12.0.0.6rlxKoSU9R8

Based on this image, http://www.smarthome.com/media/cata...3525d08d6e5fb8d27136e95/7/7/77631side1big.jpg
if you have the cable shown with the BNC connector, that's safe to plug into a composite video input... it's an industry standard connector with the same presumptions of signal type that a USB cable has -- if it fits, there should be no risk to hooking it up. (The "exception that proves the rule" is the BNC power tap on audio mixers for "LittleLite" task lighting...) You can test the long cable (if you have it) to verify that the signal wire is separate from any +12VDC or 24VAC connections.

All the ones I have used (a dozen or so) have had composite video on the yellow wire, with the black wire serving as both power and video ground.

Composite video signals span 1V, when correctly terminated with 75 ohms. With the lens capped/blocked, the waveform will (or, should) have sync, black burst, and black represented as .075 volts. This is all viewable on a basic scope, if you have one, or any CRT TV with composite video in you might pick up alongside the road as a potential sacrificial test victim. You'll need to terminate the scope input with a 75 ohm resistor for valid measurements. A TV set or VCR will terminate the signal internally. Using one to view the video signal in conjunction with the scope will both terminate the signal properly and add confidence to your reading. Any DC offset should show up with the scope or a hand-held meter.

If you don't have the magic number to pry the info out of the OEM, try asking the nav display folks. If any of the setup is brand spankin' new, you can shame them into submission, too.

Chip

Philabuster said:

I found quite a few pages showing the user manual for this camera, but this is the only page which shows the wiring diagram.

https://www.google.com/search?num=1....12.0....0...1c.1.64.serp..12.0.0.6rlxKoSU9R8

Click to expand...

That's not a wiring diagram. I have the camera apart and there are only 3 wires inside.... red, black and yellow. All I need is confirmation the red and black are for 12VDC.... based on what I see in there I'd say 99% they are, but I need to know 100% before I start troubleshooting the problem.

Finally found the source wires for that camera today (amongst a thousand other wires in a yacht) and red black are indeed the 12VDC. To my amazement the camera actually works as well.