Phantom power is the transmission of information signals and power along the wire at the same time. Mostly, remote power is used if it is not possible to connect to a 220 V power supply network. Recently, such a system has been increasingly used to power security and telephone equipment. The phantom power supply 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 varieties of this system. In the first case, the supply voltage is supplied through a separately laid cable or unused conductors of the trunk cables. In the second case, it is routed via the trunk cable along with the Ethernet network signal. In this case, additional cable conductors are not used.
The 48 V phantom power of the microphone is supplied via signal conductors. Capacitors in this case distinguish between AC and DC circuits. It should be noted that the use of the
remote power
switch must be approached with extreme caution, because if the microphone input is switched to an unbalanced signal source, unexpected power on can cause the device to malfunction (for the simple reason that voltage will be applied to it).
Phantom nutrition does not have a negative effect on balanced sources. If a keyboard or electric guitar is connected to it, then it is necessary to use switchgears, the task of which is to lower the supply voltage to the mark required by the connected device. It is also recommended to ensure that the source to which the phantom power is connected does not supply other devices requiring more current.
If we consider this phenomenon from a technological point of view, then phantom power is a rather convenient way to save copper, but only too often in practice there are various unpleasant situations. It is necessary to use a high-quality filter separator, otherwise the supply voltage may get into the signal circuits, and interference from the switching power supply circuits may get into the receiver input or the signal may die out in the power filters.
At first glance, everything may seem quite simple and understandable, but this is by no means the case. The fact is that the task of the filter is not only to separate the constant and variable components. Therefore, it must also be broadband. A broadband filter should not distort the shape of the signals. So that the acceptable length of the link does not significantly decrease, it should not lead to noticeable attenuation.
If we consider the practical use of remote power, it is worth noting that two adapters must be used on the P296 cable. That is, at each end of the link should be on the adapter. They must have separate power and information inputs. Experiments confirm: if you use adapters for the UTP5 cable, then when you use all the wires of the cable to transfer power, the range of the central power supply will almost double.