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How to add security cameras to your system

The cost of video cameras is coming down quickly. Some of these are beginning to show up as 'toys', at under $50 and even a simple black and white camera can be a valuable addition to your home automation system.
(Be sure to check out Mark's web-camera tutorial)

Whether you have worries about your baby sitter, or kids trashing your landscape, or just want to be sure you capture pictures of an intruder, here's some ideas.



You can use that old cam-corder in the closet, or you can find used bank-security cameras in the newspapers, or the auction websites. The things that matter most are that you can attach them to your VCR, and that they produce a reasonably clear image.

Although this article does assume the NTSC video standard,
the ideas are the same if your country uses the PAL or SECAM standards.

Do be careful that you make sure that the camera puts out a video signal that can be directly fed into your VCR or TV. Some models like the Connectix QuickCam put out 'serial data' signals which can only be used via your Printer or Modem or USB ports.

Here's an older model CCD camera which
was used for video conferencing.

These can often be found in the want-ads for under $50.
simple system

Although color cameras are nice, the Black and White cameras are much better for night-time surveillance. Many require only 0.5 LUX, and even a small outdoor flood provides enough light for decent pictures.

For those with deeper pockets, you can purchase an InfraRed LED type light that is not detectable by a human, but provides light to the B&W cameras just like a floodlight.

Power and Signal Wires

It will usually be easy to get power to the camera, however it may be more difficult to get a reasonably strong video signal back to the recorder.

The older bank style video cameras are powered directly by 110 volt house current, and generally have fairly strong amplifiers which can transmit their signals more than 200 feet or so. However the newer CCD cameras are powered by 12 volt wall transformers, and normally can't send signals more than about 30 feet.

In cases where the distance is too great, you will need to provide a signal amplifier, or the recorded pictures will be all but worthless.


In some cases you may want to hide the camera, and in others you may want the camera in plain sight. Regardless, you need to get power to the camera, and the video signal must be brought back either to a VCR or to your computer.

Another technique is to use a wireless transmitter and receiver which can send the video signal about 100 feet.

The newest X-10 wireless camera.
X-10 camera

camera and xmitter This transmitter will punch the signal about 100 feet.

Multiple Cameras and Switching

If you want to have multiple cameras, and don't want to buy one of the commercial camera switchers, there are a couple of techniques for this.

In both of these techniques, we must turn off either the power to all but one camera, or allow the video signal from only one camera at a time to be sent to the TV/VCR.

Here we use common X-10 appliance modules to control the power to the 'wall wart' transformers which power the cameras.

This technique doesn't require that you cut any wires, but it does take a little longer for the cameras to start up.
Appliance switcher

Here we use X-10 Universal modules to enable/disable the signal from each camera rather than switching the power.

With this technique you do have to cut into the video signal wires, but the cameras are always powered up and the video signal is immediately stable after they are switched.
Universal switcher

The Passive Adaptors in the above images are nothing more than a simple device that lets you plug two inputs into one output.
Here are some adaptors which allow you to connect the common RCA type plugs to the 'BNC' type connector which is more common with 'coaxial' type cables.

The "Y" adaptor here allows you to connect two inputs to one output.


If you need to locate your cameras more than 100' from the TV/VCR, and can't use the X-10 wireless transmitter, then you might consider using a simple amplifier available from Radio Shack.
Radio Shack part number: 15-1103 lists for $29.95

Even in this case, you can have multiple cameras using the techniques above.

I use these amplifiers for cameras that are over 300 feet away !

Although this amplifier is normally used for video and audio, I have found that even the 'audio' inputs/outputs work for 'video' signals.
Video Amplifier

Control and Switching

You can't have two or more cameras sending signals to the TV/VCR at the same time, or the signals will distort each other. So you have to manage them with XTension.

You may want to have one camera always ON, and always viewable on the monitor. And whenever a motion sensor detects an intruder at the location of another camera, you simply turn OFF the first camera and turn ON the other one.

You might want to put the Appliance/Universal modules on the same house code so that you could simply issue one "All Units OFF" command, turning all cameras OFF, and then turn ON just the camera you want.

Example Scripts for "Front Door Motion":
ON Script:
All Units OFF "C"
turn on "Front Door Camera"

OFF Script:
All Units OFF "C"
turn on "Normal Camera"

Other Thoughts

Wireless direct to the TV

There are also some very inexpensive "RF Modulators" which take the video signal from the camera and re-transmit on a standard TV channel. Thus you can have multiple cameras, each on a different channel, and then you can switch to them manually, and even use them with that fancy Picture-In-Picture feature !

Protect those outdoor Cameras

Most of the inexpensive cameras available today are not intended for 'outdoor' locations, however I've had these cameras outside for over two years, with only cellophane tape and aluminum foil protecting them.

One thing to remember that will help you enjoy your security cameras even more:

Place and aim your cameras so that you can both enjoy your landscape and watch paths and driveways...!
You might want to build a housing for them like the one shown here: camera housing

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Last modified: September 10, 2007
Michael Ferguson, webmaster@shed.com