BATTERY RUN TIME
You will need the battery (power source) rating in mAh and the power consumption (draw) in mA of the device (camera, transmitter/receiver, recorder) to calculate how long the power source will run your device.
Follow this formula and examples:
Formula
Battery mAh Camera mA draw = Run Time
Examples
9V Alkaline Batt. 625mAh 9V Camera 100mA draw = 6.25 hrs. Run Time
Our 12V Gel Rechargeable Batt. 3500mAh 12v Camera & Transmitter combined 250mA draw = 14 hrs. Run Time
Important Note
Real Life Adjustment - Devices will shut off when the required (engineered) voltage or amperage falls too low, called the "Dropout" point. This "Dropout" point varies greatly from device to device. Also, the mAh rating of a battery is rated to reflect its life to a point of discharge, but that rated point of discharge is usually much lower than the "Dropout" point of a device. So, a device may shut off before a battery is actually dead. Therefore, always purchase a power source that is 2 to 4 times more than what is needed to sustain your device and your application run time requirement. Perform a trial run before the critical use of a device and its power source.
Milliamp Hour (mAh)
Milliamps Hour (mAh) is important because it's the easiest way to distinguish the strength or capacity of a battery. The higher the mAh, the longer the battery will last. Batteries of the same voltage, but with different mAh ratings are interchangeable. If your battery is rechargeable then the mAh rating is how long the battery will last per charge.
Milliamps Hour is 1/1000th of a Amp Hour, so a 1000mAh = 1.0Ah
Think of a cars gas tank. Voltage is how much gas is being used, and mAh is the size of the gas tank. The bigger the gas tank (mAh) rating the longer the device will run.
If your battery is rechargeable, then think of the gas tank as refillable (rechargeable).
Milliamp Consumption (mA)
Every electrical device consumes energy (power). Look for the mA rating in the Specifications of the device you are seeking to purchase. The mA rating tells you how much energy the device will consume (draw) while in operation.
A milliamp is 1/1000th of an Amp, so 1000mA = 1.0A
POWER SUPPLY
Importance of a Regulated Power Supply:
A "Regulated" Power Supply, sometimes called a stabilized power supply, maintains a constant voltage regardless of voltage variations and changing load conditions. It is very important that if you do not use one of our power supply products that you verify that the unit you will use is of a "regulated" design.
Be sure to match the power (V) voltage requirement & provide a little more than the rated (mA) milliamps needed to run the component. Too much or too little Voltage can damage equipment and void the warranty. Too little milliamps and the component will not function.
Example: The component specification rates the power consumption as 12V, 150mA. In this case the Wall Power Adapter voltage can be no more or less than 12V, and the mA rating can be no less than 150mA. Use a minimum of a 200mA Wall Power Adapter to ensure the components power requirements are met in time of peak loads. You can use a higher rated mA power supply, like our 500mA Wall Power Adapter, because they only output what the component will draw.
SPY CAMERA STUFF
Image Sensors in Spy Cameras, CCD vs CMOS:
CCD (charge coupled device) and CMOS (complementary metal oxide semiconductor) image sensors are two different technologies for capturing images digitally. Each has unique strengths and weaknesses giving advantages in different applications. Because of the manufacturing differences, there have been some noticeable differences between CCD and CMOS sensors:
- CCD sensors create high-quality, low-noise images. CMOS sensors, traditionally, are more susceptible to noise.
- Because each pixel on a CMOS sensor has several transistors located next to it, the light sensitivity of a CMOS chip tends to be lower. Many of the photons hitting the chip hit the transistors instead of the photodiode.
- CMOS traditionally consumes little power. Using a CMOS sensor means a battery operated camera will have more run time.
- CCDs use a process that consumes lots of power. CCDs consume as much as 100 times more power than an equivalent CMOS sensor.
- CMOS chips can be fabricated on just about any standard silicon production line, so they tend to be extremely inexpensive compared to CCD sensors.
- CCD sensors have been mass produced for a longer period of time, so they are more mature. They tend to have higher quality and more pixels.
What does Camera Lux mean?
Lux (1/10 of a foot candle) is a standardized method by which to measure a camera's sensitivity to light. The lower the number, the less light it will take to reproduce a clear image. For example: A camera that sees down to 1 LUX, means it generally has the ability to see an image during early evening hours or just before dusk.
A camera that's down to .1 has the ability to see an image in let's say, a well lit parking lot. A rating of .05, the ability to clearly view an image in a dimly lit area at night. A .05 image can usually enable a security camera to actually see better than the human eye at night!
What does FPS mean?
FPS (frames per second) is the number of still frames (pictures) that give the illusion of motion, which appear in a single second of time.
30fps is considered "Real Time". So for Real Time viewing of your cameras, you need at least 30fps for each camera.
Example: If you have a 4 Camera DVR, you will need at least 120fps, for each camera to be considered real time.
How to determine best Security Type Camera Lens to use?
Manual Iris, Auto Iris or DC lens?
You can save money and use manual iris lens only when scene illumination never changes. Example: illuminated store or office.
If the light changes a lot it is recommended using auto-iris.
What focal length lens do I need?
Guide: smaller the focal length number => wider is field of view.
If you have security camera in the office or warehouse and you want to see as much as you can, you should go for 2.8 or 4 mm lens (makes wide, somewhat distant view).
If you want to observe limited area, like an entrance, you should go for 8mm or (makes narrow view and objects are closer).
Use varifocal lenses to get flexibility for choosing best field of view.
Basic Security Type Camera Lens info:
Video camera lenses are optical devices that attach to video cameras used in businesses, surveillance and remote monitoring applications. They are permanently fixed to video cameras, or used interchangeably with lenses of different focal lengths. There are several basic types of products: aspheric, pinhole, close-up, and wide angle. Aspheric lenses produce large angles of refraction and short focal lengths. Pinhole lenses are small-diameter devices that are designed for insertion into tubes, holes, or other small areas. Pinhole lenses with right-angle bends are called 90 pinholes. Close-up lenses provide short focusing distances for digital photography or imaging. Wide angle lenses offer a wide field of view for broad image captures.
Optical characteristics for video camera lenses include focal length, adjustability, focal ratio, minimum focusing distance, zoom capability, zoom magnification, and optical format. Focal length is the distance from the optical center of the lens to the image sensor plane. There are two types of adjustability: fixed focal length and variable focal length. A video cameras focal ratio or F-number describes the aperture of the lens as controlled by the iris. F-numbers conform to an international aperture scale in discrete values such as F1, F1.4, F2, F2.8, F4, F4.6, F8, F11, and F16. As a rule, smaller F-numbers indicate larger apertures. Minimum focusing distance and range are measured in English units such as inches (in) or metric units such as millimeters (mm) or centimeters (cm). Optical format is an approximate measure of the diagonal size of the imaging area.
Common optical formats for video camera lenses include 1/7 in., 1/6 in., 1/5 in., 1/4 in., 1/3 in., 1/2 in. 2/3 in., 3/4 in. and 1 in.
Most video camera lenses provide iris control, an aperture adjustment mechanism which regulates the amount of light that can pass. There are four basic types of iris control. Fixed iris control does not permit adjustments to account for changes in lighting conditions. Video camera lenses with manual iris control can be adjusted by hand and are designed for stable or consistent lighting conditions. Some video cameras lenses include circuitry that accepts video signals output by the camera. Other devices receive direct current (DC) outputs, but do not include integral circuitry. Video camera lenses with integral filters, anti-reflective coating, and motorized zoom magnification are commonly available.
There are several mounting styles for video camera lenses. C-mount lenses have a flange-back distance of 17.5 mm and are suitable for both C-mount and CS-mount cameras. CS-mount lenses have a flange-back distance of 12.5 mm and require a 5 mm adapter for use with C-mount cameras. S-mount video camera lenses are designed for devices such as personal computer (PC) cameras and board-mounted cameras. F-mount and K-mount video camera lenses are proprietary, bayonet-style mounting configurations.
WIRELESS OPERATION
Wireless transmitters broadcast on different radio band frequencies. Some are 434MHz, 900MHz, 1.2GHz, 2.4GHz and the newest is the 5.8GHz.
Each radio band frequency is allocated a precise and specific number of channel frequencies by the FCC.
In order to function properly all wireless audio and video devices need the specific channel frequency of the transmitter to match that of the receiver .
If you are operating more than one wireless device at the same location (crossing each others transmission range), they must broadcast on different channel frequencies. If two or more wireless devices are operating in the same location and on the same exact channel frequency, the more powerful transmitter (higher output wattage) will usually broadcast successfully.
Pushing or pulling a signal will increase signal strength or range. Pushing a signal is defined as, increasing the radiated power, milliWatts (mW), of a transmitter, therefore giving you more range. (Note: Licensing issues may become a factor. The current consumption will increase also.) Pulling a signal will require a high gain antenna attached to a receiver to pull in a signal from a further distance.
A basic "specification" shown with most wireless devices is its range, listed as Line of Sight (L.O.S.).
"Line of sight" is defined as a clear unobstructed view between the transmitter to the receiver. An analogy would be a straight beam of light, like a flashlight pointed towards the receiver with nothing in the way.
Other General Questions and Answers that may be of help to you !!
What types of devices may or may not interfere with a wireless video signal?
Some digital cellular phones, fluorescent lighting and cordless phones may or may not have an effect on any 900Mhz transmitters. 2.4Ghz transmitters in close proximity of a microwave oven, 802.11b wLANs and other products operating on the same channel and band frequency, may or may not have an effect also.
Which frequency is best used in outdoor applications?
2.4. GHz, followed by 900 MHz, followed by UHF.
Which frequency is better for penetration through walls?
UHF, followed by 900 MHz, followed by 2.4GHz.
How many elves are needed to make a wireless camera?
None, and they prefer to be called "little people".
Can I add cable and extend the distance between the receiver and the receiver antenna?
Generally it is not recommended, though it depends on the cable and the frequency you are using. In general the longer the cable between the antenna and receiver the greater the loss of signal strength.
How far away can the transmitter be from the camera?
As far as the cable type will allow you before losing one-volt, peak to peak. Generally RG-59 cable will allow you 750ft before the video quality decreases.
Audio Line Level and Mic Level:
Audio "line level" is an audio input that has not been pre-amplified. Similar to an electric guitar, striking the cords will make a slight sound, but if you plug it into an amplifier, you will have a lot of sound. Mic level is an audio source that has been already amplified. Therefore you can plug your microphone directly into the audio input without "pre-amplifying" the source.
(see Spy Topics for more detailed information).
