An analog CCTV camera captures images and transmits video signals over a coaxial cable to a recording device, such as a VCR or DVR.
Here's a breakdown of how it works:
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Image Capture: The camera uses a sensor, typically a CCD (Charge-Coupled Device) or CMOS (Complementary Metal-Oxide-Semiconductor) sensor, to capture light. This sensor converts the light into an electrical signal.
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Signal Processing: The electrical signal is processed by the camera's internal circuitry. This processing involves amplifying the signal, correcting for any distortions, and converting it into a standard analog video format, such as NTSC (National Television System Committee) or PAL (Phase Alternating Line).
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Signal Transmission: The analog video signal is then transmitted over a coaxial cable to a recording device. Coaxial cable is used because it is well-shielded and provides good signal quality for analog video transmission.
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Recording and Display: The recording device (VCR or DVR) receives the analog video signal. A VCR would record the signal onto magnetic tape. A DVR (Digital Video Recorder) digitizes the analog signal and stores it on a hard drive. The video can then be displayed on a monitor or viewed remotely (if the DVR is networked).
Key Components and Their Functions:
| Component | Function |
|---|---|
| Lens | Focuses light onto the image sensor. |
| Image Sensor | Converts light into an electrical signal. |
| Processing Circuitry | Amplifies, corrects, and formats the electrical signal into a standard analog video signal. |
| Coaxial Cable | Transmits the analog video signal to the recording device. |
| Recording Device | Records the analog video signal (VCR) or digitizes and stores it digitally (DVR). |
In summary, analog CCTV cameras work by converting light into an electrical signal, processing that signal into a standard analog video format, and transmitting it over a coaxial cable to a recording device.
