US 6,192,435 B1Granted

Apparatus for allowing smooth hot insertion and removal of a peripheral by gradually applying and removing power to the peripheral

AssigneeMitsubishi Denki Kabushiki Kaisha

InventorAkira Takahashi

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Abstract

An interface between a main computer 20 and a peripheral unit 30 allows connection/disconnection of the peripheral unit to and from the main computer during the operation of the main computer, while achieving reduction of fluctuation in the source voltage caused by hot line connection/disconnection, as well as a reduction of the circuit size. The interface includes a connector having long terminal pairs and short terminal pairs, by which the peripheral unit 30 is connected to the main computer 20. The peripheral unit 30 contains a delay circuit comprised of a FET 10 for controlling ON/OFF operation of the electric current path, a capacitor C1, and resistors R1 and R2. The signal path containing R1 and R2 forms a closed loop only when the peripheral unit is completely inserted into the main computer. During the insertion, the long terminal pairs are first connected, which is followed by connection of the short terminal pair. After the connection of the short terminal pair, C1 is charged and the FET 10 is gradually switched ON. During the extraction of the peripheral unit, C1 starts being discharged after disconnection of the short terminal pair and the FET 10 is gradually turned OFF. As a result, electric current supply is varied smoothly. In another embodiment a movable element for securing and releasing the peripheral unit from connection with the main unit closes and opens a switch in the current path between the delay circuit and the main unit.

Claims4

Dependent claims

An interface apparatus for connecting through insertion/extraction, a peripheral unit to and from a main unit during electrical operation of the main unit, the peripheral unit being powered by electric current fed from the main unit through the interface apparatus, comprising:

control means for controlling electric current supplied from the main unit to the peripheral unit, wherein,
upon insertion said control means prohibits supply of electric current before the peripheral unit reaches a completely inserted state, gently increases electric current supply during a first predetermined time period after the peripheral unit is in the completely inserted state, wherein said control means maintains a steady electric current supply after said first predetermined time period, and wherein upon extraction of the peripheral unit, said control means gently decreases electric current supply during a second predetermined time period after the peripheral unit is out of the completely inserted state, and wherein the control means stops the electric current supply after the second predetermined time period;
and
a switch in an electric current loop between said control means and said main unit, said switch being closed in response to movement of a movable element for securing and releasing the connection between said peripheral unit and said main unit to a first securing position, such that electric current is allowed to flow from said main unit to said control means upon closure of said switch, thereby initiating said first predetermined time period, and said switch being open in response to movement of said movable element to a second releasing position, such that electric current is stopped from flowing from said main unit to said control means upon opening of said switch, thereby initiating said second predetermined time period.

1 more element

Dependencies are inferred from the claim text.