What is the role of the manufacturer?(3)
Ring current backup
The ring current generator is mainly used in the telephone exchange exchange to provide ringing to the telephone users, and is generally used in a biased state. Bias can be divided into positive bias and negative bias. In order to improve the reliability of the ring current system, the ring current needs to be backed up. Installation and maintenance of module power supply
Since the types, series and specifications of the modular power supplies produced by various companies are difficult to count, their functional characteristics and physical characteristics are not the same, so they are also different in installation, use and maintenance, but the following aspects should be paid attention to
Input protection circuit General dc switching 48V input power supply supply products use built-in filters, which can meet the requirements of general 48V input power supply applications. If a more demanding power system is required, manufacturer the input filter network should be added. Either LC or π can be used but care should be taken to choose a smaller inductance and larger capacitance.
In order to prevent the transient high voltage damage of the dc switching 48V input power supply supply, it is recommended that the user connect the transient absorption diode to the input terminal, and cooperate with the fuse to ensure that the module is within the safe input voltage range. In order to reduce the common mode noise, Y (Cy) can be increased and several capacitors nf high frequency capacitors are generally selected. R is a fuse, D is a protection diode, and D is a transient absorption diode (P6KE series).