Telecom power supplies

It is increasingly clear that eventually, the law is going to place significant additional EMI requirements on all on-board power converters and any power supply, off-line or otherwise, working inside telecom equipment. Therefore, in the not so unforeseeable future, we could soon all be routinely testing the outputs of every power supply in much the same manner as we test their inputs today. In fact even as of now, many of the big telecom equipment manufacturers, of their own volition, routinely comply with CISPR 22 limits on both the inputs and outputs of their telecom power supplies. Of course, instead of the special proposed ISN, they have just gone ahead and used the more readily available input LISN to test the outputs too. 

See Figure 13-2 for an example of how EMI suppression techniques are applied to dc-dc converters. We have shown an industry standard isolated brick (along with its external EMI filtering). The input to this particular module is a coarsely regulated 18 V-dc or -60 V-dc bus, forming part of a distributed power architecture for a data/telecom network. Its output is isolated and regulated (e.g. 3.3 V/50 A or 12 V/10 A etc). The -48 V-dc input is usually derived from an off-line telecom power supply (called a rectifier ). 

A telecom project required a rack of several 3000 W Power Factor Corrected (PFC) hot-pluggable power supplies. Two brilliant teams went about it, one writing C++ code and the other designing the power sections and the backplane. This was to operate off a 3-phase AC mains supply. 

Stationary (uninterrupted power supply for hospitals, utilities, telecom))... 

Zhu Huibo Qin Yulong 2010. Design of motor vehicle charging power supply based on the UC3875 [J]. Telecom Power Technology. 

Axane Is a wholly-owned subsidiary of the Air Liquids group. It alms to develop fuel cells systems powered by hydrogen, which are the core of the power supply offer proposed by Air Liquide Hydrogen Energy. These turnkey energy solutions are for new emerging markets (telecom antennas, one-off outdoor events, off-grid sensors, etc.)... 

This switching power supply (Figure 1.35) was designed for high-reliability telecom applications where there was a requirement for a light-weight. 

In 2011, General Electric in the USA began producing nickel chloride batteries under the name Durathon. They are intended for grid-connected renewable energy storage, telecoms applications and, more generally, backup power supply and industrial transport needs. 

Acumentrics Corporation of Westwood, Massachussetts, USA, has produced several 2 kW size fully integrated rapid-start SOFC systems using microtubular cells, and delivered them to prospective customers. These systems operate on natural gas, and the intended application is as uninterruptible power supplies for broadband, computer and telecom backup. 

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