Surveillance cameras often use devices that enhance security. Of these devices, it is worth highlighting microphones. A microphone connected to the camera complements the picture of what is happening in the observation area. In this article we will talk about the microphones of the company "Shorokh", their characteristics, model range and connection diagram.
The model range of the manufacturer includes 8 devices. Models are distinguished by the following main criteria :
- automatic gain control (AGC);
- acoustics distance range;
- ultra high level of sensitivity (microwave).
All devices of the model range have common characteristics:
- power supply 5-12 V;
- range up to 7 m;
- frequency up to 7 kHz.
It is worth noting that the “rustle” microphones have versatility in operation . Depending on the model, microphones can be used in any noisy companies or rooms with soundproofing. Devices are also installed to monitor street observations. The presence of AGC makes it possible to record high-quality sound without loss of signal, regardless of the degree of sound in the room where the observation takes place.
Devices have miniature dimensions. Therefore, microphones can be installed even in hard-to-reach places.
Miniature microphone "rustle-1"
Audio has high-quality sound transmission, high sensitivity and low noise level of its amplifier. It is worth noting the permissibility of connecting to the low-frequency input of VCRs and video monitors for audio recording. Also, "rustle-1" will provide high-quality sound on standard video surveillance monitors. Device Properties:
- range up to 5 m;
- signal level output 0.25 V;
- supply voltage 7.5-12 V.
The main features of the device are low power consumption, small size and nickel housing, which prevents interference and unnecessary noise. Of the minuses, there is a lack of AGC.
Main characteristics of the active device:
- range up to 7 m;
- signal level 0.25V;
- the presence of AGC;
- nickel-plated aluminum housing that prevents unnecessary interference.
Thanks to the presence of AGC, the device maintains a high level of signal output regardless of the sound in the controlled area. Also, the presence of AGC involves the operation of the model in soundproof rooms.
Like the previous model, "Rustle-7" provides high-quality sound with access to various devices for video surveillance.
The device is practically no different from the "rustle-7". The main difference between the model is the lack of noise of the built-in amplifier, as well as high sensitivity. Of the characteristics, it is worth noting the acoustic range of up to 10 m.
Directional model. Its properties:
- range up to 15 m;
- signal level 0.6 V;
- line length 300 m;
- power supply 7-14.8 V.
The main features of the device are the microwave and the absence of amplifier noise.
Despite the fact that the model is not equipped with AGC, the device is in great demand. An audio microphone is used when observing in noisy areas, as well as outdoors. The model records high quality audio and connects to the low-frequency input of various monitors and tape recorders. It is also possible to connect to computer boards via a standard audio input.
Active microphone has the following features:
- acoustic distance range up to 15 m;
- output voltage level 0.6V;
- high degree of noise protection;
- power supply 7.5-14.8V.
The directional microphone has a microwave function. The metal housing provides protection against various types of interference, including interference from mobile devices, TV towers, walkie-talkies. The device has the ability to connect to any video surveillance technique, has hypersensitivity and a minimum degree of amplifier noise.
A distinctive feature of the model from all previous ones is the presence of adjustment of the output audio signal. Also, the device can be used when working with computer boards and Euclid boards.
How to choose?
The choice of audio recording device should be based on the upcoming tasks that this device will perform. However, there are general criteria for choosing a microphone.
- Sensitivity It was believed that the higher the sensitivity, the better. This is not true. An overly sensitive device can pick up any interference. But weak sensitivity is not a good choice. Your device may simply not recognize weak sounds. Manufacturers claim that when pairing the resistance of the pickup and the performance of the amplifier system, the microphone will give an excellent result.
- Directivity . Directional devices are selected by distance to the monitored area. As a rule, the manufacturer indicates the directional characteristics on the packaging of the goods.
- Sizes . Sound quality and frequency range directly depend on the size of the membrane. If you want to get a good surround sound result, you should pay attention to models with large dimensions.
When choosing a device for the street, it is necessary to take into account the degree of protection from the external environment. Due to the amount of noise for street cameras or DVR cameras, only directional devices are selected.
How to connect?
Small-sized audio microphones have red, black, and yellow wires. Where red is voltage, black is grounding, yellow is audio. To connect an audio microphone, use a 3.5 mm jack or RCA tulip plug. The wire is soldered to the plug. A red + 12V conductor is connected to the (+) power supply. A blue conductor or minus (common) is connected to the external element of the connector and to the (-) power terminal. A yellow audio cable is connected to the main pin. The power source is the power supply unit to which the video surveillance device is connected.
Users often wonder about the type of cable. When connecting microphones to cameras, experts recommend using a coaxial cable. What type of cable will be used depends on the range of the surveillance zone. With a range of acoustics up to 300 m, a flexible ShVEV cable with a cross section of 3x0.12 is used. With an acoustic range of 300 to 1000 m (for indoor use), the KVK / 2x0.5 cable is suitable. Range from 300 to 1000 m (on the street) implies the use of KVK / 2x0.75.
The coaxial cable connection diagram is as follows.
- First, a + 12V red conductor is connected to the (+) power supply .
- Then the blue conductor (minus) of the microphone is connected to the (-) cord of blue color , then to the power supply and then in parallel to the braid of the coaxial wire and to the outer element of the connector. These actions must be performed simultaneously.
When connecting a microphone using the above methods , remember the polarity. If the microphone needs to be connected to the speakers of the computer, then the connection is via the 3.5 mm input. The signal voltage at the output is enough to connect the microphone to both the speakers and any other device. The model range of the company “Shorokh” is represented by devices that can provide a high level of security and high-quality sound recording.
You must also remember that when connecting, you must adhere to the wiring diagram and comply with safety rules.
You will learn more about how to connect the Shorokh-8 microphone to the DVR.