Phantom power - is the transfer of information signals on the wire and power simultaneously.Mainly used in remote power supply if there is no possibility to connect to the mains of 220 V. In recent years, such a system is increasingly used for food security, and telephone equipment.Block phantom power can also be successfully used to connect a microphone, keyboard or electric guitar.
Depending on the method of supplying the supply voltage, there are two variants of this system.In the first case the supply voltage is supplied via separately installed cables or unused conductors of the main cable.In the second case it is sent by the main cable with the signal Ethernet network.The additional conductors of the cable are not used.
phantom power to the microphone 48 is supplied through the signal conductors.Capacitors in this case delimit circuit AC and DC.It should be noted that the use of a remote power switch must be approached with caution, because in the case of switching to an unbalanced microphone input signal source unexpected power-failure can cause the device (for the simple reason that it will be energized).
phantom power on balanced sources of negative influence does not render.If connected to it keyboard or electric guitar, you need to use distribution systems, whose task is to reduce the supply voltage to the level required by the plug-in device.It is also recommended to ensure that the source that is connected to phantom power, do not eat other requiring high-current devices.
If we look at this phenomenon from a technological point of view, the phantom power is pretty convenient way to save copper, but too often, in practice, there are various unpleasant situations.It is necessary to use a filter separator of high quality, otherwise, the signal lines can enter the supply voltage and the input of the receiver may enter the interference from the pulse power supply circuits or power filter may attenuate the signal.
At first glance, it may seem quite simple and straightforward, but this is not so.The fact that the problem is not only the filter in the separation of the constant and variable components.Therefore, it has yet to be broadband.Filter in a wide frequency band should not distort the shape of the signals.To acceptable length of the link is not significantly reduced, it should not lead to a noticeable attenuation.
If we consider the practical application of remote power supply, it is worth noting that the cable P296 necessarily need to use the two adapters.That is, at each end of the link must be on the adapter.They must have separate power supply inputs and data inputs.Experiments confirm if the cable UTP5 use adapters, when used for the transfer of power cable conductors, the distance of the central powering increased almost two-fold.
