US 5,675,467 AGranted

Circuit mounting unit

AssigneeFujitsu Limited

InventorsHisayuki Nishimura, Shigeru Honda, Naohiro Shibata

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Abstract

The present invention relates to a circuit mounting unit that can prevent a voltage drop and noise occurrence due to current inflow at the time of a hot insertion or withdrawal operation without mounting a capacitor with large capacitance on the side of a main unit. The circuit mounting unit includes a first voltage control unit that controls to increase gradually a voltage supplied to a load voltage converter from the main unit side to a predetermined voltage when the circuit mounting unit is exchangeably inserted into or pulled out of the main unit without halting electric power supplied from the main unit. The circuit mounting unit is mounted onto a printed wiring board on which various elements such as ICs and LSIs are previously mounted to form a predetermined circuit.

Claims26

Dependent claims

A circuit mounting unit, comprising:

a first element connected to a main unit via a connector, driven by a first voltage which is supplied from said main unit;
a load voltage converter for converting said first voltage from said main unit into a second voltage different from said first voltage;
a second element driven by said second voltage converted by said load voltage converter;
and
a first voltage control unit for boosting gradually a voltage supplied from said main unit to said load voltage converter into said first voltage when an insertion operation to said main unit is performed without halting a power supply from said main unit,
said first control unit including:
a variable resistor that varies from a high resistance state thereof to a low resistance state thereof as a switching voltage externally added increases,
a switching voltage converter that converts an electric power from said main unit into said switching voltage to supply to said variable resistor, and
a capacitor inserted between an output terminal from said switching voltage of said switching voltage converter and a ground line,
said variable resistor in said first voltage control unit being connected to a power supply line from said main unit to said load voltage converter.

7 more elements

A circuit mounting unit, comprising:

a first element connected to a main unit via a connector, driven by a first voltage which is supplied from said main unit;
a load voltage converter for converting said first voltage from said main unit into a second voltage different from said first voltage;
a second element driven by said second voltage converted by said load voltage converter;
a first voltage control unit for boosting gradually a voltage supplied from said main unit to said load voltage converter into said first voltage when an insertion operation to said main unit is performed without halting a power supply from said main unit;
a bypass line for bypassing said first voltage control unit and said load voltage converter to supply an electric power from said main unit to said second element;
a diode connected to said bypass line;
and
a second voltage control unit for controlling to increase gradually a voltage sneaking from said main unit to said load voltage converter via said bypass line when said insertion operation is performed.

5 more elements

Dependencies are inferred from the claim text.