Regulating arrangement for solenoid valves and the like

Claim 2

In combination with the solenoid of an electromagnetically actuated mechanism, particularly a high-speed solenoid valve, of the type requiring a higher activating current to effect movement of the armature from a first to a second position and a lower holding current to maintain the armature in such second position, an arrangement for regulating the current flow in said solenoid, the arrangement comprising a power supply connected to said solenoid; switch means connected to said power supply and connected to said solenoid and operative for initiating a buildup of current in said solenoid; and control means responsive to the solenoid current and operative for stabilizing the voltage across said solenoid until the solenoid current reaches a predetermined threshold value, said control means comprising a negative-feedback loop including controllable impedance means connected in circuit with said power supply and said solenoid and carrying at least a portion of the current flowing through said solenoid, feedback-signal amplifier means having an output connected to said controllable impedance means, and means connected to said solenoid and connected to the input of said feedback-signal amplifier means for applying to the latter a negative-feedback signal dependent upon the voltage across said solenoid and serving to vary the impedance of said controllable impedance means in a sense counteracting changes of the voltage across said solenoid from a predetermined value.

Claim 3

Arrangement as defined in claim 1, wherein said control means further includes current-regulating means operative after said threshold value has been reached for maintaining the solenoid current at a holding value lower than said threshold value.

Claim 4

Arrangement as defined in claim 1, wherein said control means includes current monitoring means for detecting when the solenoid current reaches said threshold value.

Claim 5

An arrangement as defined in claim 1, wherein said controllable impedance means comprises a power-transistor having a collector-emitter path connected in the current path of the solenoid, and wherein the solenoid and said collector-emitter path are together connected across said power supply, whereby changes in the collector-emitter voltage of said power transistor will result in opposite changes of the voltage across the solenoid.

Claim 6

Arrangement as defined in claim 4, wherein said control means includes current-regulating means operative after said threshold value has been reached for maintaining the solenoid current at a holding value lower than said threshold value, and wherein said current-regulating means includes negative feedback means for applying to the base of said power transistor a voltage corresponding to the solenoid current.

Claim 7

Arrangement as defined in claim 5, wherein said control means includes current monitoring means for detecting when the solenoid current reaches said threshold value.

Claim 8

An arrangement as defined in claim 1, wherein said means for applying to the input of said feedback-signal amplifier means a negative-feedback signal dependent upon the voltage across said solenoid is operative only until the solenoid current has reached said predetermined threshold value, and wherein said control means further includes means operative after the solenoid current has reached said predetermined threshold value for applying to said input of said feedback-signal amplifier means a negative-feedback signal dependent upon the solenoid current, to form another negative-feedback loop serving to effect variations in the impedance of said controllable impedance means in a sense counteracting deviations of the solenoid current from a predetermined holding value lower than said predetermined threshold value.

Claim 9

An arrangement for regulating the current flow in the solenoid of an electroMagnetically actuated mechanism, particularly a highspeed solenoid valve, of the type requiring a higher activating current to effect movement of the armature from a first to a second position and a lower holding current to maintain the armature in such second position, comprising, in combination, a power supply connected to the solenoid; switch means for initiating a build-up of current in the solenoid; and control means responsive to the solenoid current and operative for maintaining the voltage across the solenoid substantially constant until the solenoid current reaches a predetermined threshold value, said control means comprising a power transistor having a collector-emitter path connected in the current path of the solenoid, and the solenoid and said collector-emitter path being together connected across said power supply, so that changes in the collector-emitter voltage of said power transistor will result in opposite changes of the voltage across the solenoid, said control means further including first negative feedback means for applying to the base of said power transistor a voltage corresponding to the voltage across the solenoid, and wherein said control means includes current-regulating means operative after said threshold value has been reached for maintaining the solenoid current at a holding value lower than said threshold value, said current-regulating means comprising second negative feedback means for applying to the base of said power transistor a voltage corresponding to the solenoid current, said first negative feedback means comprising feedback-signal amplifier means for amplifying a voltage corresponding to the solenoid voltage and applying such amplified voltage to the base of said power transistor, and said current regulating means comprising a current-monitoring transistor whose output is connected to the input of said feedback-signal amplifying means, and a series resistor connected in the solenoid current path and connected across the base-emitter circuit of said current-monitoring transistor and having a resistance value such as to render said current-monitoring resistor conductive when the solenoid current reaches said threshold value, and wherein said series resistor is operative for applying to the base-emitter circuit of said current-monitoring transistor a voltage corresponding to solenoid current, whereby said current-monitoring transistor will apply to said feedback-signal amplifying means a signal corresponding to the solenoid current.

Claim 10

An arrangement for regulating the current flow in the solenoid of an electroMagnetically actuated mechanism, particularly a highspeed solenoid valve, of the type requiring a higher activating current to effect movement of the armature from a first to a second position and a lower holding current to maintain the armature in such second position, comprising, in combination, a power supply connected to the solenoid; switch means for initiating a build-up of current in the solenoid; and control means responsive to the solenoid current and operative for maintaining the voltage across the solenoid substantially constant until the solenoid current reaches a predetermined threshold value, said control means comprising a power transistor having a collector-emitter path connected in the current path of the solenoid, and the solenoid and said collector-emitter path being together connected across said power supply, so that changes in the collector-emitter voltage of said power transistor will result in opposite changes of the voltage across the solenoid, said control means further including first negative feedback means for applying to the base of said power transistor a voltage corresponding to the voltage across the solenoid, and wherein said control means includes current-regulating means operative after said threshold value has been reached for maintaining the solenoid current at a holding value lower than said threshold value, said current-regulating means comprising second negative feedback means for applying to the base of said power transistor a voltage corresponding to the solenoid current, said first negative feedback means comprising feedback-signal amplifier means for amplifying a voltage corresponding to the solenoid voltage and applying such amplified voltage to the base of said power transistor, and said current regulating means comprising a current-monitoring transistor whose output is connected to the input of said feedback-signal amplifying means, and a series resistor connected in the solenoid current path and connected across the base-emitter circuit of said current-monitoring transistor and having a resistance value such as to render said current-monitoring resistor conductive when the solenoid current reaches said threshold value, and wherein said series resistor is operative for applying to the base-emitter circuit of said current-monitoring transistor a voltage corresponding to solenoid current, whereby said current-monitoring transistor will apply to said feedback-signal amplifying means a signal corresponding to the solenoid current.

Claim 11

An arrangement as defined in claim 8, wherein said control means includes voltage divider means whose tap is connected to the base of said current-monitoring transistor and which has a first resistance portion connected between said tap and the output of said power transistor and a second resistance portion including said series resistor as well as a diode and a further resistor connected between said tap and one terminal of said series resistor, and wherein the component values of the components of said voltage divider means determine the ratio between said threshold value and said lower holding value of solenoid current.

Claim 12

An arrangement as defined in claim 8, wherein said control means includes constant-current source means for establishing a flow of biasing current through said series resistor and thereby establishing said threshold value by establishing the additional solenoid current necessary to cause said series resistor to render conductive said current-monitoring transistor.

Claim 13

An arrangement as defined in claim 10, wherein said constant-current source means is adjustable and thereby operative for adjusting the magnitude of said holding value.

Claim 14

In combination with the solenoid of an electromagnetically actuated mechanism, particularly a high-speed solenoid valve, of the type requiring a higher activating current to effect movement of the armature from a first to a second position and a lower holding current to maintain the armature in such second position, an arrangement for regulating the current flow in said solenoid, the arrangement comprising a power supply connected to said solenoid; switch means connected to said power supply and to said solenoid and operative for initiating a build-up of current in said solenoid; first negative-feedback stabilizing means operative during build-up of solenoid current and until such current reaches a predetermined threshold value for maintaining the voltage across said solenoid substantially constant at a predetermined value; and second negative-feedback stabilizing means operative after the solenoid current has reached said threshold value thereafter maintaining the solenoid current substantially constant at a holding value lower than said threshold value.

Claim 15

In combination with the solenoid of an electromagnetically actuated mechanism, particularly a high-speed solenoid valve, of the type requiring a higher activating current to effect movement of the armature from a first to a second position and a lower holding current to maintain the armature in such second position, an arrangement for regulating the current flow in said solenoid, the arrangement comprising a power supply connected to said solenoid; switch means connected to said power supply and to said solenoid and operative for initiating a build-up of current in said solenoid; first negative-feedback stabilizing means operative during build-up of solenoid current and until such current reaches a predetermined threshold value for maintaining the voltage across said solenoid substantially constant at a predetermined value; and second negative-feedback stabilizing means operative after the solenoid current has reached said threshold value thereafter maintaining the solenoid current substantially constant at a holding value lower than said threshold value.

Claim 16

In combination with the solenoid of an electromagnetically actuated mechanism, particularly a high-speed solenoid valve, of the type requiring a higher activating current to effect movement of the armature from a first to a second position and a lower holding current to maintain the armature in such second position, an arrangement for regulating the current flow in said solenoid, the arrangement comprising a power supply connected to said solenoid; switch means connected to said power supply and to said solenoid and operative for initiating a build-up of current in said solenoid; and negative-feedback stabilizing means connected to said power supply and connected to said solenoid and operative after the solenoid current has built up to a predetermined threshold value for thereafter maintaining the solenoid current substantially constant at a holding value lower than said threshold value.

Claim 17

In combination with the solenoid of an electromagnetically actuated mechanism, particularly a high-speed solenoid valve, of the type requiring a higher activating current to effect movement of the armature from a first to a second position and a lower holding current to maintain the armature in such second position, an arrangement for regulating the current flow in said solenoid, the arrangement comprising a power supply connected to said solenoid; switch means connected to said power supply and to said solenoid and operative for initiating a build-up of current in said solenoid; and negative-feedback stabilizing means connected to said power supply and connected to said solenoid and operative after the solenoid current has built up to a predetermined threshold value for thereafter maintaining the solenoid current substantially constant at a holding value lower than said threshold value.