Posts Tagged ‘ PIR’



Motion Activated Security Camera

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Wednesday, April 6th, 2011

There are many purposes for using a motion activated security camera.  Portably, the most popular reason for using the motion activated security camera is to conserve electronic resources.  On the other hand, these cameras may be used for an entirely different reason; to provide alerts like an alarm system when something is there.

There are also several different types of motion activated security cameras.  In this article, we’ll explore how these cameras work, describe some of the more popular types, and talk about what how they may be used.

Many of today’s digital video camera security systems use wireless cameras.  This option provides great versatility in camera mounting types and locations.  A wireless camera does not require the usual RG-59 or similar type of cable to be run directly from the camera to the Digital Video Recorder or DVR and or monitor.

Instead, the camera has a built in radio transmitter and an on-board antenna.  It converts its video data into a radio signal and transmits it via the transmitter/antenna combination to a corresponding receiver or a DVR that contains a built in receiver.  As noted above, this can provide great freedom in cameral location and mounting choices.

However, the camera still needs a power supply.  So a power supply wire needs to be run from either a nearby outlet plug (if there is one) or from a power distribution box.  Since the wireless camera has gained great strides in achieving freedom from the wireless transmission, the power supply wire could possibly continue to restrict that freedom.  So, enter the new battery operated wireless, digital video security camera.

However, these cameras can place a hefty drain on batteries requiring frequent replacement or recharging.  So what is the solution to unnecessary battery drain?  A motion activated security camera.  These cameras contain an on-board motion detector that turns the camera on when it detects motion.  Since the motion detector itself consumes a fraction of the total power that a recording camera does, battery power is greatly conserved and battery life or recharging periods are greatly lengthened.

This same sort of principle is also used on hidden, disguised, or covert cameras.   Due to the nature of these cameras, they are often subjected to running on battery power.  Once again, a 12 hour recording of an empty room can not only be wasteful, but use tremendous amounts of battery life.  Make the device with a built in motion detector and the camera is now a motion activated security camera.

The types of cameras we’ve mentioned so far work by using a Passive InfraRed (PIR) motion detector.  The PIR has the ability to sample the average heat signature in the field of view of which it is aimed (usually the same field of view as the camera).  When an object with a different temperature than the surroundings, such as a body, a vehicle, etc. passes in front of the PIR it can detect this sudden change in the heat signature of the field of view.

The PIR interprets the heat signature change as an object in motion.  The PIR is connected to an electronic relay such that when motion is detected, the PIR tell the relay to turn the switch on to the camera and start recording.  The camera either stops when the PIR no longer detects motion or at a designated time period when after motion ceases.

There is another type of motion activated security camera that doesn’t work on the basis of Passive InfraRed activity.  This camera is usually left in an “on” state where it is constantly capturing the visual image in its field of view.  Instead of using a PIR, programming analyzes the video image that is being captured to determine if there is a change in any of the basic patters of the current field of view.

When a change is detected, the camera is activated such that although it is already on and capturing video images the camera now initiates processing and recording.  In other words on this type of system, the camera is on an capturing but not necessarily transmitting its video data to a monitor or DVR.  However, when the on-board programming detects a change in the otherwise motionless scenery, the camera initiates full recording and transmitting of its video signals.

This particular type of motion activated security camera is often used as a Pan-Tilt-Zoom camera that can track and follow objects based on the motion that it detects.

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Security Lights with Camera

Written By:
Tuesday, January 11th, 2011

Talk about “getting caught in the act,” that’s exactly what security lights with camera will do. Using a security lights with camera device will not only illuminate the subject with a flood of high wattage bright white light, but it will take still pictures or video images of them too.

It’s a proven fact that the incidence of crime is decreased in areas that are well lit by bright security lights. Obviously, criminals and trespassers are less likely to frequent areas that are strongly lit because of a higher probability of being caught and ultimately being prosecuted. In addition, both the London, England and New York City police departments have also proven that the mere presence of video cameras reduces the incidence of crime. So why not combine these two into one with a security lights with camera system that offers the power and protection of both?

Generally, a security lights with camera system is a self contained unit. However, using motion detectors, digital video camera illuminators, and digital video cameras, it is conceivable that a custom made security lights with camera system can also be constructed. However, for this article we will limit our discussion to the more common self-contained units.

The self contained security lights with camera system is usually one unit that consists of three major components: 1) A high wattage extra bright floodlight; 2) A motion detector relay; and, 3) A digital video camera and mini Digital Video Recorder or DVR. The unit can be mounted just about anywhere that a regular house current AC power line can be connected to it. The specific locations for mounting the unit are virtually endless. Here’s a partial list of suggested uses or places to mount the unit:
• Front and back of residences near possible points of entry;
• Boat slips and docks;
• Entrances to storage facilities;
• Inside storage facilities that are normally not lit at night;
• Back entrances to stores and other business locations;
• Entrances to barns and/or equipment sheds;
• Property that is posted with “No Trespassing” signs; and
• Machinery and other valuables kept outside.

A typical security lights with camera unit will contain a high-wattage motion activated halogen lamp. Most units use halogen elements rate at about 500 watts. Mounted somewhere on the unit (usually directly below the lamp) is a built-in digital video security camera. Both the lamp and the camera are activated by an on-board motion detector so that when motion is detected, a relay activates the camera and turns on the security light at the same time.

The motion detector used in these units is usually a PIR or Passive InfraRed motion detector. The PIR works by scanning the field of view of the camera and security light. It detects the inherent infrared radiation being emitted in this field of view. When a sudden change in the infrared radiation signature occurs, it interprets this to be an object in motion (such as a human walking past it). The PIR sensor is connected to a relay that is then switched to the “On” position activating both the security light and digital video camera at the same time.

The camera immediately begins taking pictures or digital video footage. Since digital video is actually several digital photographs taken at a high rate of speed in succession, the security lights with camera unit allows you to set it in advance to take either digital still photographs or digital video. The digital photographs or video are saved by the on-board DVR.

The mini on-board DVR usually consists of some sort of built in memory that can be expanded by adding additional memory devices to it (such as a thumb drive, an SD card, etc.) To access the digital photographs or videos, simply remove the portable digital memory media and plug it into your computer.

The entire one piece unit is normally rated as an outdoor device meaning that it can protect the components from weather and other elements (like dust). Installation usually consists of:
1) Mounting the unit and adjusting the aim;
2) Connecting it to a typical residential type AC power line;
3) Inserting the portable memory media; and,
4) Setting the camera and light for duration of the “On” state and the type of digital picture format.

That’s all there is to it. So if you are looking for maximum security at a safe distance with relatively low price, you should consider purchasing a security lights with camera system today.

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Outdoor Wireless Systems Alarm

Written By:
Friday, October 1st, 2010

An outdoor wireless security systems alarm is usually some sort of motion detector sensor(s) that when actuated initiates some sort of audible or silent signal. There are several variations on this theme, including digital video camera systems that can function as an outdoor wireless security systems alarm. However, the purpose of any of these variations is the same; alert the user when a defined boundary or perimeter has some sort of motion-detectable activity and do it by using sensors that do not require wired connections.

There are several uses for outdoor wireless security systems alarms that work on the basis of motion detection. This sort of system can be used as a welcome chime for your business or home. If your residence has a particularly long driveway these alarms are excellent for notifying you when you have a visitor or delivery.

Likewise, an outdoor wireless security system alarm can be used to alert you to the presence of someone or something (such as an animal) in a boundary or perimeter. These are particularly useful in industrial and other business applications where safety and security concerns mandate that no unauthorized persons are allowed in specific areas. Residentially, a perimeter can be defined around your house or property and whenever this area has been breeched the alarm can alert you immediately, giving you advanced notice of someone’s presence. They are also great for use in securing outdoor swimming pools, water features, or ponds.

There are two basic types of outdoor wireless security systems alarm units, based on their function. The first type is a standalone outdoor wireless security systems alarm and the other is an integrated sensor that communicates with a central control unit that has additional zones connected to it such as doors and windows for example.

A standalone unit usually consists of a wireless motion detector sensor that transmits its signal to a corresponding wireless receiver. The receiver unit is often about the same size as a cell phone and usually contains its own speaker and chime/alarm sound to notify you when the sensor has been actuated.

The integrated sensor consists of a wireless motion detector sensor that transmits its signal to a corresponding wireless receiver that is hard-wired to a central control unit, or to a central control unit that contains its own on-board wireless receiver. Actuation of this sensor sends a signal to the control unit that may react in several ways including sounding an alarm or chime, notifying a professional monitoring service, or even turning on a light or series of lights.

Regardless of how the signal is received, the motion detector sensors basically work the same on the basis of infrared wave technology known as PIR or Passive InfraRed Sensing. The PIR sensor measures the infrared radiation from objects with its range or area of view. Motion detection is based on the change of infrared radiation detected when an object with one heat signature passes in front of another object with a different heat signature. Of course the infrared radiation is invisible to the human eye but readily detectable to the sensor.

Outdoor wireless security systems alarm sensors should be constructed to withstand the elements. Many high-quality sensors have been evaluated to the Ingress Protection Code and have a rating of IP55 or higher. In addition, most outdoor wireless sensor units operate on a standard or rechargeable battery. Some manufactures claim a normal operating period of up to two years on one battery.

Many sensors have selectable fields of view or ranges. It is common for a sensor to contain a switch that can select a 45 foot range or a 15 foot wide angle pattern for example to allow for specific user needs.

Transmission ranges vary based on sensors, manufacturers, types etc. but it is not uncommon to find outdoor wireless security systems alarm sensors that have ranges up to 1000 feet or more. However, most of these manufacturer specified ranges are based on Line of Sight or LOS. LOS range means the distance between the sensor’s antenna and the receiver’s antenna without any objects blocking the view between the two. Generally, objects that do impede the LOS do not necessarily prevent transmission but most often reduce the range. The reduction of the LOS range varies based on the object or material that impeded the LOS such as a window, wall, building, trees, etc.

The cost of an outdoor wireless security systems alarm varies but are normally very affordable for both residential and business applications.

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