Solenoid valve driving circuit and solenoid valve
First Claim
1. A solenoid valve driving circuit in which, after a first voltage is impressed on a solenoid coil of a solenoid valve for driving said solenoid valve, a second voltage is impressed on said solenoid coil and a driven state of said solenoid valve is maintained,the solenoid valve driving circuit being electrically connected, respectively, to a direct current power source and to said solenoid coil, and further comprising a switch controller, a switch, and a current detector,wherein said current detector detects a current flowing through said solenoid coil, and outputs a detection result, as a current detection value, to said switch controller,wherein said switch controller generates a first pulse signal based on a comparison between a predetermined activation current value and said current detection value, and a second pulse signal based on a comparison between a predetermined holding current value and said current detection value, and supplies said first pulse signal and said second pulse signal to said switch, andwherein said switch applies a power source voltage of said direct current power source as said first voltage to said solenoid coil during a time period when said first pulse signal is supplied thereto, and applies said power source voltage as said second voltage to said solenoid coil during a time period when said second pulse signal is supplied thereto.
1 Assignment
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Accused Products
Abstract
A current detection circuit generates a pulse signal Sd based on a voltage Vd corresponding to a current I flowing through a solenoid coil, and feeds the pulse signal Sd back to a PWM circuit of a switch controller. The PWM circuit generates a pulse signal Sr having a predetermined duty ratio, based on a comparison between the fed back pulse signal Sd and a voltage value corresponding to a first current value or a second current value, and supplies the pulse signal Sr to a pulse supplying unit. The pulse supplying unit supplies the pulse signal Sr as a first pulse signal S1 and/or a second pulse signal S2 to a gate terminal G of a MOSFET.
41 Citations
18 Claims
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1. A solenoid valve driving circuit in which, after a first voltage is impressed on a solenoid coil of a solenoid valve for driving said solenoid valve, a second voltage is impressed on said solenoid coil and a driven state of said solenoid valve is maintained,
the solenoid valve driving circuit being electrically connected, respectively, to a direct current power source and to said solenoid coil, and further comprising a switch controller, a switch, and a current detector, wherein said current detector detects a current flowing through said solenoid coil, and outputs a detection result, as a current detection value, to said switch controller, wherein said switch controller generates a first pulse signal based on a comparison between a predetermined activation current value and said current detection value, and a second pulse signal based on a comparison between a predetermined holding current value and said current detection value, and supplies said first pulse signal and said second pulse signal to said switch, and wherein said switch applies a power source voltage of said direct current power source as said first voltage to said solenoid coil during a time period when said first pulse signal is supplied thereto, and applies said power source voltage as said second voltage to said solenoid coil during a time period when said second pulse signal is supplied thereto.
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4. A solenoid valve driving circuit in which, after a first voltage is impressed on a solenoid coil of a solenoid valve for driving said solenoid valve, a second voltage is impressed on said solenoid coil and a driven state of said solenoid valve is maintained,
the solenoid valve driving circuit being electrically connected, respectively, to a direct current power source and to said solenoid coil, and further comprising a switch controller, a switch, and a current detector, wherein said current detector detects a current flowing through said solenoid coil, and outputs a detection result, as a current detection value, to said switch controller, wherein said switch controller generates a first pulse signal based on a comparison between a predetermined activation current value and said current detection value, and a predetermined second pulse signal, and supplies said first pulse signal and said second pulse signal to said switch, and wherein said switch applies a power source voltage of said direct current power source as said first voltage to said solenoid coil during a time period when said first pulse signal is supplied thereto, and applies said power source voltage as said second voltage to said solenoid coil during a time period when said second pulse signal is supplied thereto.
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7. A solenoid valve driving circuit in which, after a first voltage is impressed on a solenoid coil of a solenoid valve for driving said solenoid valve, a second voltage is impressed on said solenoid coil and a driven state of said solenoid valve is maintained,
the solenoid valve driving circuit being electrically connected, respectively, to a direct current power source and to said solenoid coil, and further comprising a switch controller, a switch, and a current detector, wherein said current detector detects a current flowing through said solenoid coil, and outputs a detection result, as a current detection value, to said switch controller, wherein said switch controller generates a predetermined first pulse signal, and a second pulse signal based on a comparison between a predetermined holding current value and said current detection value, and supplies said first pulse signal and said second pulse signal to said switch, and wherein said switch applies a power source voltage of said direct current power source as said first voltage to said solenoid coil during a time period when said first pulse signal is supplied thereto, and applies said power source voltage as said second voltage to said solenoid coil during a time period when said second pulse signal is supplied thereto.
Specification