The wide use of wireless video transmission system: 0. Wireless security monitoring system This is the biggest use of this module. It has the advantages of strong confidentiality, power saving, small size, concealed appearance, and there are too many places that can be used. Both the transmitter and the receiver are powered by AC. Together with the SS2000CA color camera, a complete wireless monitoring system can be formed. If it cooperates with human body detection circuit, such as radar intrusion sensor and pyroelectric sensor to detect human body, when people enter the monitoring area, the wireless remote control coding circuit is activated, and a power-on command is issued to turn on the remote video recorder for recording. 4 or less) placed in different rooms, you can take turns to monitor multiple rooms by changing channels at the receiving end.
1. The super-angle remote control of the model. The ultra-small wireless sound and image transmission system can add a pair of bright "electronic eyes" to the high-end remote control model to achieve super-angle remote control. Because the entire device has a very small size and power consumption, it can be easily added to the car. Inside the model or ship model, the power supply can be shared with the control power supply of the model. You can drive the car model to other rooms as long as you lie on the bed through the miniature monitor to see if there is any movement? Or drive the boat model to the middle of the lake to see where the small animals are. Or install it on a remote control helicopter and look down at the city you are familiar with from a high altitude.
2. Wireless door mirrors or video doorbells sold on the market are usually wired transmission. If your home has been renovated, it is generally difficult to arrange video and audio cables. Here you can use an ultra-small wireless sound and image transmission system through the TV The machine displays the sound and image of the door. The mini camera can be installed in the proper position of the gate with sound monitoring function. The signal is transmitted through the wireless audio and video transmitter. The wireless audio and video receiver can send the received sound and image signal. Into the AV input socket of the TV, so you can see the person coming at the door and hear his voice as long as you switch the TV to the AV state after hearing the doorbell. You can also buy a 4-inch or 5-inch LCD monitor for special monitoring. There are many small LCD monitors on the market. Most of these monitors are modified with imported second-hand LCD screens, so the price is relatively cheap and the performance is relatively low. Good and bad. The LCD screen is divided into true color TFT and pseudo color SNT. The price of pseudo color is very low, and there is a phenomenon of dynamic smearing. If the image changes rapidly, it will be blurred, mainly because of the long dynamic response time. The pseudo color type is not suitable for display. TV screen or VCD, but the image change of general security monitoring is not drastic, and the use of false color for monitoring can be described as good and cheap. True-color images are colorful, with wide viewing angles without dynamic smearing, and better performance. However, the performance of different real-color LCD screens also varies greatly, mainly because of the angle of view and color reproduction, etc., be sure to see what you see is true!
3. The wireless mobile video recording and forensic system began on April 1, 2002. The court adopted the evidence of secret filming and secret recording, but the court did not recognize it before, so the wireless mobile video recording and forensic system has a very large Practical value. If the video output signal of the receiver of the wireless sound image transmission device is sent to a small household video recorder, the dual functions of monitoring and recording can be realized. Most of the commercially available small camcorders are digital 8mm camcorders. Note that models with analog signal video / audio input and output must be selected. Most of these small camcorders have a 2.5 to 4 inch LCD screen. The monitor image can be displayed through the display screen, and the video tracking function can be used to record the image tracked by the ultra-micro wireless transmitter, which greatly improves the security capabilities and forensics. effect. At present, there are many types of small digital video recorders on the market, most of which are portable, such as DCR? TRV410E, 310E, 210E, 110E, CCD? TRV66E, DCR-TRV900E and so on. Although the above-mentioned models are smaller in size, they are much larger than ultra-miniature cameras and have limited concealment and mobility. The entire system requires two people to cooperate in the transmission and reception operations. At the same time, the distance between the two people always maintains the actual effective distance range of wireless transmission and reception, you can roam and track the target for real-time monitoring, and accurately collect videos and recordings as needed, which is not only suitable for In the field of security, it can also be used for various scientific investigations that require mobile tracking monitoring.
4. High-altitude surveillance If you attach a miniature camera and a wireless image transmission device to a hydrogen balloon or a helium balloon, you can carry out high-altitude surveillance for a long time. You can see very far targets. You can do it in large gatherings or on the water. Image monitoring.
5. The wireless image anti-theft alarm system for vehicles can form a practical anti-theft image monitoring system if it incorporates a vibration displacement sensor such as ND-1 plus a coded remote control circuit and a wireless transmission system, which has great market potential. This type of circuit is actually relatively simple, and the webmaster can design it.
6. The remote-controlled covert surveillance system ultra-mini pinhole camera plus a micro-transmitter equipped with a suitable rechargeable battery can form a wireless monitoring device. If you use the remote control code to remotely control the power supply of the transmitting device, you can achieve long-term monitoring at any time. The device can be easily placed in a plush toy, and can be monitored in a hidden manner, and has a wide range of uses.
7. Wireless "Babe" surveillance treasure This is a product that is quite common abroad, mainly used to monitor the baby's every move, even if the baby does not sleep with the adult. Can be made into flashlight size, adjust the angle and use.
8. Anti-theft security warning confirmation The use of pyroelectric, microwave induction, infrared and other sensors can easily design anti-theft security circuits, but it is inevitable that false alarms will occur due to the performance of electronic components and the external environment. If multiple false alarms will inevitably cause The guard's thoughts were slack, and the real "wolf is coming!" If the wireless audio and video transmission system is turned on at the same time as the alarm sensor alarms, the sound and images on the spot are transmitted to the duty room immediately by the camera, and the duty officer will immediately confirm whether the alarm is true. Lights, which undoubtedly expose criminals,
This system has several advantages:
1. At the same time as an alarm, immediately confirm whether it is a real situation
2. To avoid direct contact of security personnel with criminals and protect personal safety
3. You can call the police without disturbing the criminal, and catch the turtle in the urn
4. Can use fewer security personnel to achieve multi-point security monitoring
9. Industrial robot vision system Some industrial robots are required to be able to enter the equipment for maintenance and measurement, and need to transmit the image inside the equipment to the outside for monitoring and remote control, such as oil pipeline welding seam detection robot, engine endoscopic robot, detonation robot And so on, can be achieved using a wireless sound image transmission system.
10. If you want to take a picture of a city, aerial photography is usually the best choice, but the cost of renting a helicopter for aerial photography is also quite expensive. If you use an aerial model for shooting, the cost will be greatly reduced, as long as the aerial model The load is sufficient, install the camera or camera on the model, stop the model in the designated airspace, and then start the camera or camera remotely. It is necessary to have a framing system. If there is no view angle and effect of the image captured by the framing system, it may be It is difficult to determine that the image seen by the camera is transmitted to the ground through a high-power wireless audio and video transmission device. If the image is satisfactory, the camera or camera can be started at any time to shoot.
11. Unannounced interviews with television news often cover the dark side of society directly, and the news clues interviewed are very convincing and shocking, so now such news programs are constantly increasing, and wireless video equipment can be used to wirelessly transmit the pictures taken by reporters to the car. Within, monitor and record. This scheme has two advantages: First, the transmitter is small and easy to hide, and will not be discovered by the interviewee. The interviewee has no mental burden and can often speak his heart. Second, some interview missions are inherently dangerous. If the interviewee suspects that the interview will often cause siege or beating, the command vehicle can contact the police in time to rescue and rescue.
12. Investigation and evidence collection by industry, commerce, taxation and environmental protection departments In order to investigate and collect evidence, the industry, commerce, taxation and environmental protection departments can also use such equipment to display the most intuitive evidence to the leaders of the punished department and convince the punished department to take it by mouth.
13. Firefighters individual fire scene visual system Firefighters themselves are quite dangerous when they rush into the fire scene to rescue and save people. When a single firefighter is equipped with a wireless audio and video transmission system, the actual situation inside the fire scene can be transmitted to the command vehicle. It can timely deploy fire extinguishing programs and rescue orders according to the actual situation, and can also organize rescue in time when firefighters themselves are in danger. If combined with video equipment for recording, the cause of fire can be analyzed and the fire fighting plan can be optimized afterwards. This is the general plan: using the Japanese Ikeda 1 watt machine, 10.8V / 2.4AH lithium battery, micro camera, ultra-high brightness red LED lighting flashlight.
14. The elevator security monitoring system is in a small elevator, which is prone to robbery, intimidation, sexual harassment, etc. After being equipped with a wireless audio-visual system, such things can be prevented, and when the elevator fails, it can also keep abreast of the safety of the elevator personnel.
15. TV station entertainment and adventure programs More and more TV stations have launched adventure and game programs. These programs are highly interactive, such as high-altitude bungee jumping and roller coaster. If you fix a small camera on the helmet of the participant, shoot the player The facial expressions or the viewing angles seen by the players are transmitted to the ground through wireless audio and video equipment, and superimposed on the scene in a small picture way will definitely increase the visibility of such programs. In fact, many TV stations have already done so.
16. If the mobile monitoring point places the camera and wireless audio and video equipment inside the motorcycle or car, adjust the camera angle of view, and borrow the 12-volt power supply inside the motorcycle or car for long-term hidden surveillance. This has an unparalleled advantage in criminal detection (remember the film that Feng Gong made that reflects the hard work of public security personnel monitoring squatting points?) Technical characteristics of wireless audio and video transmission systems: the wireless audio and video system uses high-frequency electromagnetic wave signals as a carrier It is used to transmit audio and video signals, so the transmission effect is limited by the electromagnetic wave transmission characteristics. Taking the 1.2GHZ microwave as an example, its wavelength is very short, so the diffraction performance is very poor, and it is not easy to penetrate obstacles, so the best The transmission environment is: there is no obstruction between the transmitter and the receiver, which is the so-called line-of-sight transmission. The transmission effect of wireless audio-visual equipment is also related to several other factors:
1. The effective height of the transmitter and receiver. The theory of radio transmission tells us that the higher the height of the transmitter and receiver, the farther the transmission distance. If conditions permit, the transmitter and receiver are placed as high as possible, so TV stations and radio stations are built very high.
2. The electromagnetic interference intensity of the use environment. When wireless audio-visual equipment is used in an industrial place with severe electromagnetic radiation, if the emission frequency of the interference source is close to the 1.2G frequency, it will cause serious interference to the equipment. Wireless audio-visual equipment modulates signals by frequency modulation. The frequency discriminator at the receiving end must have sufficient signal-to-noise ratio to detect useful signals. When useful signals are submerged in ambient noise, wireless audio and video transmission cannot be achieved.
3. Wireless audio and video equipment needs a good power supply. It is the basic guarantee for the normal operation of any circuit. The requirements of wireless audio and video equipment on power supply are also strict. First, the power supply must meet the working voltage of the equipment. Low will make the equipment not work properly. Moreover, the ripple coefficient of the power supply should be small enough. When using the battery as the power supply, it is necessary to consider that the transmission power will be reduced after the battery voltage drops. Wireless audio and video equipment with different transmission power Transmission distance power under different environments ABCD 50mw 100m 30m 20m 50m 100mw 200m 50m 40m 100m 200mw 400m 70m 60m 200m 700mw 800m 120m 100m 400 Meters 1000mw 1000 meters 200 meters 150 meters 500 meters 2000MW 2000 meters 500 meters 450 meters 1100 meters 3000MW 3000 meters 800 meters 500 meters 1500 meters 5000MW 5000 meters 1500 meters 1200 meters 3500 meters 10000MW 10000 meters 4000 meters 3600 meters 5000 meters
1. "A" in the table means open area without obstruction.
2. "B" in the table indicates that the indoor building material is a brick structure.
3. "C" in the table indicates that the indoor building material is a cement grouting structure.
4. “D†in the table indicates that there is a block of high-rise buildings. The data in the table is subject to errors depending on whether the room is the same floor and the size of the building. The design points of the wireless audio and video transmission system: When designing and installing a perfect wireless audio and video system, we must fully consider the actual situation of the use environment, the size and power consumption of the transmitter, the affordable price, the necessary functions, etc. The high power of the equipment cannot be required blindly, even if the high power equipment of 1 watt is used, the transmission distance is limited in the actual environment. If there are more than three walls between the transmitting and receiving ends, the transmission distance will be greatly shortened. To expand the transmission distance:
1. Using high-gain antenna system 15DB high-gain double-helix directional antenna, using multi-helix transmitting element, compared with the use of ordinary 2DB small antenna can increase the transmission distance by 3 to 5 times, the antenna size is 48 cm high, the base 32 cm is relatively large, the base is an octagonal plastic seat, which can be fixed on the mast by two "U" shaped metal pieces, or fixed on the wall by expansion bolts. The high gain of the directional antenna is at the expense of the transmission angle, so the transmission angle of the directional antenna is only about 30 degrees. The installation angle needs to be adjusted during installation to achieve the best effect. It is more suitable for long-distance point-to-point fixed transmission images. Because of the high price of directional antennas, directional antennas can be used at the transmitting end and small omnidirectional antennas at the receiving end when the project budget is tight. Equipped with 2 meters long high-frequency cable and special connectors for easy connection and use. The 13DB high-gain Yagi directional antenna can increase the transmission distance by 3 to 5 times compared with the ordinary 2DB small antenna. The antenna size is 80CM long and is fixed to the wall by expansion bolts. The high gain of the directional antenna is at the expense of the transmission angle, so the transmission angle of the directional antenna is only about 30 degrees. The installation angle needs to be adjusted during installation to achieve the best effect. It is more suitable for long-distance point-to-point fixed transmission images. Because of the high price of directional antennas, directional antennas can be used at the transmitting end and small omnidirectional antennas at the receiving end when the project budget is tight. Equipped with 2 meters long high-frequency cable and special connectors for easy connection and use.
2. The 1.2G microwave transmission characteristic of the wireless-to-wired system is that the ability to cross obstacles is poor. We can use video cables to wire the places that are not suitable for microwave crossing, such as dense walls, metal doors and windows, so that both The transmission power of the wireless video and audio transmission equipment can be reduced, the cost can be reduced, and a satisfactory effect can be obtained. The wired transmission area can be selected from the camera to the transmitter and the receiver to the monitor according to actual needs.
3. It is designed as an active antenna. You know that if you put the antenna on a high place, it can not only avoid obstacles but also help to transmit, and can greatly increase the transmission distance, but if you pass the RF power from the transmitter through a long dedicated high frequency When the cable is led to the antenna, the power loss on the feeder is also considerable, and it does not achieve satisfactory results. In fact, because the volume of the wireless audio and video transmitter is relatively small, the transmitter and antenna can be used by means of waterproof and moisture proof Then fix it directly at a high place, and then introduce the power cable, video cable, and audio cable into the transmitter, thinking that even if these wires are extended by several tens of meters, the transmission effect will not be affected. In actual operation, the transmitter and the small antenna can be installed into the appropriate diameter In the PVC plastic pipe, it is best to deal with moisture.
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