| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a discharge circuit largely reduced in power loss during an operation in comparison with a conventional discharge circuit, and preventing the complicatedness of a control. <P>SOLUTION: The constant-power discharge circuit 1 is composed of: a transistor Q adjusting a discharge current I<SB>D</SB>by a gate voltage; a shunt resistor R<SB>D</SB>' outputting a reference voltage E<SB>R</SB>proportional to the discharge current I<SB>D</SB>adjusted by the transistor Q; and a constant-power control circuit 3 determining a discharge-current set value I<SB>D*</SB>in response to a residual voltage E<SB>C</SB>gradually lowered by a discharge while controlling the gate voltage so that the discharge current I<SB>D</SB>is equalized to the discharge-current set value I<SB>D*</SB>by comparing the set value I<SB>D*</SB>and the reference voltage E<SB>R</SB>. The constant-power control circuit 3 compares the residual voltage E<SB>C</SB>and a comparison voltage preset in response to one or more changed nodes, and changes the discharge-current set value I<SB>D*</SB>when the residual voltage E<SB>C</SB>is lower than the comparison voltage. <P>COPYRIGHT: (C)2009,JPO&INPIT |
