Distribution Amplifier : Circuit, Working, Types , Vs splitter & Its Applications

An amplifier is an electronic device that uses audio or video signals as input to amplify their frequency to improve quality & after that provide these input signals to two (or) more outputs. Audio (or) video signal strength and signals’ uniform distribution are modified using Amplifier devices. Distribution of a signal can be done without any depletion ground loop or media signal degradation by a distribution amplifier (DA). These amplifiers transmit analog and digital signals. This article provides brief information on a distribution amplifier, its working, and its applications.

What is a Distribution Amplifier?

The distribution amplifier definition is; a type of amplifier that is used to allow a single input signal & provides this similar signal to various isolated outputs. The function of a distribution amplifier or DA is to take an audio or video signal as an input, & amplify it to output this amplified signal to a minimum of two (or) more outputs. This amplifier is mainly used to provide a single audio or video signal to various equipment. Distribution amplifiers are analog or digital type devices that allow the multiplexing of audio (or) video signals in identical intensity.

These types of amplifiers are appropriate for amplifying the audio (or) video signals being transmitted through fiber optic cables, coaxial copper cables (or) HDMI cables. These devices have obtained maximum popularity in the operations of video multiplexing within video production and video security, the surveillance industry, the distribution industry, etc. These amplifiers are mainly designed for supporting analog, digital (or) a combination of analog & digital types of signal.

How Does a Distribution Amplifier Work?

A distribution amplifier works simply by accepting a single input signal to provide this same signal to several isolated outputs. So these amplifiers allow an input signal to be distributed to various destinations with no signal degradation & ground loops. Distribution Amplifiers divide both signals.

These amplifiers are very helpful in maintaining the power of signals received, ensuring all the o/p receivers you are using accept them at an equal level with no degradation of excellence. DAs have typically extremely low output impedance, thus changes within the load won’t affect the output voltage. The primary purpose of these amplifiers is to compensate for the power loss that occurs after dividing the signal to distribute audio or video signals to multiple locations.

Video Distribution Amplifier Circuit

The video distribution amplifier circuit is shown below. The video distribution for different TVs or recorders without distortion or losses is fairly difficult. So, to resolve this issue, this video distribution amplifier circuit is used.

The required components to make this circuit mainly include; resistors R1 – 470 Ω, R2-10 KΩ, R3 & R4 – 1 KΩ, R5 – 330 Ω, R6 to R13 – 150 Ω, R14 – 6.8 Ω, VR1 – 1 KΩ. Ceramic disc capacitors like; C1, C4, C5, C7, C11, C13, C15, C17 to C20 – 0.1 µF, electrolytic capacitors C2 & C8 – 100 µF/16V, C3 & C9 = 10 µF/16V, C6 – 220 µF/16V, C10, C12, C14, C16 – 470 µF/16V, C21 & C22 – 2200 µF/25V.

Differential video amplifier IC1 – 733 IC, fixed series +5V voltage regulator IC2 – 7805 IC, fixed series -5V voltage regulator IC3 – 7905 IC, Bi-polar NPN power transistor T1 & T2 – BD139, signal diodes D1 & D2 – 1N4148, rectifier diodes D3 to D6 – 1N4002, Miscellaneous X1 = 230V AC primary to 9V to 0 to 9V AC 200mA secondary transformer Heat sinks. Connect the circuit as per the circuit diagram shown below.

Power Supply

The power supply of this circuit is very straightforward & simple. The transformer X1 is used to step down the main AC supply. The secondary transformer’s output is rectified through a bridge rectifier which includes D3 diodes throughout D6 & filtered through capacitors C21 & C22. The regulated +5V and -5V from 7805 IC2 and 7905 IC3 regulators in the circuit power the entire circuit.

Working

The video distribution amplifier circuit uses popular single-chip amplifiers like; IC 733 IC1. This chip can be used for amplifying the signal with up to 20 MHz bandwidth but this circuit is used for up to 10 MHz only because the bandwidth of video is about 5 MHz max. The gain given by this IC is five times which must be above sufficient to balance for loading losses & cable losses.

The input video signal is given to the video distribution circuit through a filter circuit made from two parallel capacitors. The VR1 variable resistor simply allows to set the amplification to some level & provided to the input of IC 733. The output of this IC from pin-7 is provided to a buffer amplifier that is made with T1 & T2 transistors.

Here, the T2 Transistor serves as a current source for transistor T1. For both of these transistors, we utilize heat sinks because their effective current is set to 100 mA. When long coaxial cables are used, the resistor networks act as an impedance-matching network at the output.

During the video distribution, some distortion & losses might take place to reduce the video quality, so this circuit helps reduce that problem. With this video distribution amplifier, you can link four TVs or video recorders to a single VCR or VCP output. The circuit can be used as a distribution amplifier for VCP or VCR, as well as for other signals with about 10 MHz of bandwidth.

Distribution Amplifier Types

Distribution amplifiers are classified into two types based on the amplifier’s transmission potential analog & digital distribution amplifiers. Similarly, the distribution amplifiers based on the media type being transmitted are available in two types; audio and video distribution amplifiers which are discussed below.

Analog Distribution Amplifiers

The distribution amplifiers that use analog signals as input & amplify the signal to a high frequency to distribute it into several outputs are known as analog distribution amplifiers. These types of amplifiers improve the waveform by enhancing features like fixed (or) variable signal strength, peak amplitude, etc.

Digital Distribution Amplifiers

We use digital distribution amplifiers to amplify and distribute digital media signals. These amplifiers provide signal rectification, eliminating the need for signal buffering. By employing re-clocking, we can easily maintain bit error, transmission rate, and data path integrity.

Audio Distribution Amplifiers

The audio distribution amplifiers are either analog type or digital type. Usually, the audio signals from intercoms & speakers are analog. These amplifiers are suitable for amplification of certain audio signals & bifurcation.

However, when the audio distribution multimedia signal is being transmitted, the audio signals are converted into a digital format. The digital audio can be spread with digital audio amplifiers.

A single audio feed, like a line input or microphone input, is usually taken by this amplifier, which is also known as a press feed, a media feed, a pool feed, an ADA, or a press box, and it outputs several line or microphone outputs. The primary function of this amplifier is to transmit a single.

Video Distribution Amplifiers

This distribution amplifier is distinguished based on the standards of video transmission which is also called distribution amp (or) VDA. The input used for this type of amplifier is a video signal, which amplifies this signal & gives the amplified video signal to two (or) more outputs. This amplifier is mainly used for supplying a single video signal to various parts of video equipment. This amplifier simply changes the video signal’s amplitude to recompense for signal loss within a video distribution system.

Distribution Amplifier Vs Splitter

The differences between the distribution amplifier and splitter are discussed below.

How to Select Distribution Amplifier?

To achieve optimal results, it is crucial to select a distribution amplifier that meets specific requirements. In industrial settings, signal transmission operations exhibit flexibility. Therefore, it is necessary to consider certain essential factors when selecting an amplifier to meet specific operational needs.

Input to Output Port Ratio

The distribution amplifier must be selected by considering its port ratio, which is the ratio of the number of input ports to the number of output ports. This amplifier has only one input port, which can only be connected to a single recipient device. In contrast, the output ports should be sufficient to connect all the recipient devices.

Return Path Ability

The distribution amplifier or DA is a two-way communication device. We prominently use forward transmission from the input port to the output ports, but return path transmission can also be very important. To perform this transmission, one can enable the return path within the distribution amplifier, but the device’s ability to return signals should be sufficient to sustain return transmission. So, you should check the device’s return path ability when choosing it.

Gain of Amplifier

The gain of the amplifier is the amplification amount within the signals. Designers usually intend for directional antennas (DAs) to provide a gain of +15 dB per amplification cycle. However, if the amplification results in a negative gain, this is considered a signal loss.

Requirements of Power

Considering power requirements and the availability of power sources, select DAs with power inserters (or) frontline power inputs.

Compatibility of Third-Party Device

Eliminating the possibility of direct communication links being established by the amplifier, third-party devices like fiber optics can integrate the distribution amplifier. However, the amplifier’s compatibility with the devices within an IC has implications for the overall network performance. So, the DA compatibility with other devices such as network switches, fiber optics cables, media converters, etc should be verified before installation.

Installation Requirements

The Das installation requirements differ frequently based on the conditions of the environment & transmission length from one amplifier to another (or) a third-party device. So, their operating conditions & particular application requirements should be analyzed very carefully.

Applications

The applications of distribution amplifiers include the following.

• Professional media companies, bars, restaurants, recording studios, and event centers commonly use distribution amplifiers to supply a single video signal in more permanent environments.
• The distribution amps are significant whenever there is one signal source only. However, there are several recipients. This amplifier will amplify the frequency & distribute the signal to several devices without reducing the audio (or) video signal quality.
• These are analog or digital devices that allow the audio (or) video signals multiplexing in consistent intensity.
• A distribution amplifier device divides a single audio or video signal to duplicate it into several copies.
• An HDMI DA allows an operator to display audio & video from a single HDMI signal source to numerous HDMI LCDs/TVs.
• The distribution amplifiers are highly significant within the media production & outsourcing industry.
• These amplifiers are applicable in Television, multimedia, post-production operations, satellite communications, video surveillance networks, RF signal processing, video multiplexing, channel switching, and cable connection networks.

Thus, this is an overview of a distribution amplifier, circuit, working, types, and its applications. DAs are electronic devices, used widely in audio or video signal amplification & distribution operations. Some of the operations that are extremely dependent on these amplifier devices are; CCTV surveillance, multimedia streaming, and many more. The distribution amplifier device installation poses the danger of electrocution because of the chance of residual electric current in the network even after the main power supply termination. To avoid these risks, it is necessary to obtain these services from specialists & achieve the installation safely & meticulously. Here is a question for you, what is an amplifier?