1. A motor driving apparatus driving a multiphase motor comprising:
a motor driver which includes a parallel circuit in which a plurality of series circuits are connected in parallel, each of the plurality of series circuits having a high side switching device and a low side switching device connected in series;
a voltage detector which detects a voltage at a neutral point of the multiphase motor during a first period and outputs the detected voltage as a first detection signal, the first period being identical to or a part of a period for which all of the high side switching devices orand all of the low side switching devices are in an on state in the parallel circuit;
a first timing detector which detects a timing at which a voltage of the first detection signal equals to a first reference voltage, and outputs the detected timing as a second detection signal;
a periodic signal generator which generates a periodic signal whose phase is controlled based on the second detection signal; and
a driving signal generator which generates, by using the periodic signal, a plurality of driving signals with each of which one of the high side and low side switching devices in the parallel circuit is driven.
2. The motor driving apparatus according to claim 1, wherein said periodic signal generator generates a sinusoidal wave signal.
3. The motor driving apparatus according to claim 1, wherein said voltage detector comprises:
a neutral voltage detector which detects the voltage at the neutral point of the multiphase motor during the first period and outputs the detected voltage as a third detection signal; and
a filter which extracts only a predetermined frequency band of the third detection signal and outputs a signal of the extracted frequency band as the first detection signal.
4. The motor driving apparatus according to claim 1, wherein said first timing detector comprises a comparator which compares the voltage of the first detection signal with the first reference voltage, and outputs a result of the comparison as the second detection signal.
5. The motor driving apparatus according to claim 1, wherein said voltage detector comprises:
a neutral voltage detector which detects the voltage at the neutral point of the multiphase motor during the first period and outputs the detected voltage as a third detection signal; and
a filter which extracts only a predetermined frequency band of the third detection signal and outputs a signal of the extracted frequency band as the first detection signal,
wherein said first timing detector comprises,
a rate detector which detects a rate of change of the first detection signal and outputs the detected rate as a fourth detection signal, and
a comparator which compares a voltage of the forth detection signal with a second reference voltage, and outputs a result of the comparison as the second detection signal.
6. The motor driving apparatus according to claim 1, wherein said voltage detector comprises:
a neutral voltage detector which detects the voltage at the neutral point of the multiphase motor during the first period and output the detected voltage as a third detection signal; and
an amplifier which amplifies the third detection signal and output an amplified signal as the first detection signal.
7. The motor driving apparatus according to claim 1, wherein said voltage detector comprises a sample-and-hold unit which samples and holds the voltage at the neutral point of the multiphase motor during the first period and outputs a sampled-and-held voltage as the first detection signal.
8. The motor driving apparatus according to claim 7, wherein said voltage detector further comprises a carrier wave generator which generates a carrier wave,
said periodic signal generator generates a plurality of periodic signals each of which corresponds to one phase of the multiphase motor,
said sample-and-hold unit samples and holds the voltage at the neutral point of the multiphase motor, during a period, corresponding to the first period, for which a voltage of the carrier wave is larger than a voltage of each of the plurality of periodic signals, and
said driving signal generator generates the plurality of driving signals by modulating the plurality of periodic signals with the carrier wave.
9. The motor driving apparatus according to claim 8, wherein said periodic signal generator comprises:
a current detector which detects a current flowing in the whole parallel circuit and outputs a value of the detected current as a current detection signal; and
a difference amplifier which amplifies a difference between a voltage of the current detection signal and a third reference voltage, and outputs the amplified difference,
wherein said periodic signal generator generates the plurality of periodic signals each of which has an amplitude corresponding to a voltage of the amplified difference.
10. The motor driving apparatus according to claim 9, wherein said periodic signal generator generates the plurality of periodic signals each of which has an amplitude equal to the voltage of the amplified difference, and
said sample-and-hold unit samples and holds the voltage at the neutral point of the multiphase motor, during a period, corresponding to the first period, for which the voltage of the carrier wave is larger than that of the amplified difference.
11. The motor driving apparatus according to claim 10, wherein said sample-and-hold unit comprises an adder which adds the voltage of the amplified difference and a predetermined positive voltage, and outputs a result of the addition as an addition voltage,
wherein said sample-and-hold unit samples and holds the voltage at the neutral point of the multiphase motor during a period, corresponding to the first period, for which the voltage of the carrier wave is larger than the addition voltage, and outputs a sampled-and-held voltage as the first detection signal.
12. The motor driving apparatus according to claim 11, wherein said sample-and-hold unit further comprises a phase inverter which inverts a phase of the carrier wave and outputs the carrier wave with the inverted phase,
wherein said sample-and-hold unit samples and holds the voltage at the neutral point of the multiphase motor, during a period, corresponding to the first period, for which a voltage of the carrier wave with the inverted phase is larger than the addition voltage.
13. The motor driving circuit according to claim 7, wherein said sample-and-hold unit comprises a first on-period detector which detects, from the plurality of driving signals generated by said driving signal generator, the period for which all of the high side switching devices orand all of the low side switching devices are in an on state in the parallel circuit as a first on-period, and outputs the detected first on-period as a first on-period detection signal, and
wherein said sample-and-hold unit samples and holds the voltage at the neutral point of the multiphase motor during the first period and outputs the sampled-and-held voltage as the first detection signal, the first period being identical to or a part of the first on-period.
14. The motor driving circuit according to claim 13, wherein said first on-period detector outputs the first on-period detection signal which is a binary signal whose level is different between the first on-period and the other period,
said sample-and-hold unit further comprises:
a first delay circuit which delays the first on-period detection signal by a first delay time, and outputs the delayed signal as a first delay signal;
a second delay circuit which delays the first delay signal by a second delay time, and outputs the delayed signal as a second delay signal; and
a second on-period detector which detects, by using the first and second delay signals, the second delay time after a time when a level of the first delay signal changes in a predetermined manner as the first period;
wherein said sample-and-hold unit samples and holds the voltage at the neutral point of the multiphase motor during the first period and outputs the sampled-and-held voltage as the first detection signal.
15. The motor driving apparatus according to claim 1, further comprising:
a current detector which detects a current flowing in the whole parallel circuit and outputs a value of the detected current as a current detection signal; and
an oscillator which outputs an oscillation signal of a predetermined frequency;
wherein said motor driver includes the plurality of series circuits each of which corresponds to one phase of the multiphase motor,
said periodic signal generator generates the plurality of periodic signals each of which corresponds to one phase of the multiphase motor, each of the plurality of periodic signals indicating a value of a maximum possible current to flow in the high side switching device or the low side switching device of the series circuit corresponding to one phase of the multiphase motor, and
said driving signal generator generates the plurality of driving signals to turn off the high side and low side switching devices in each of which a current indicated by the current detection signal flows, when the current is larger than the maximum possible current indicated by a corresponding periodic signal, and then turn on the turned-off switching devices at a timing synchronous with the predetermined frequency of the oscillation signal.
16. The motor driving apparatus according to claim 15, wherein said voltage detector comprises a sample-and-hold unit which samples and holds the voltage at the neutral point of the multiphase motor during the first period, and outputs the sampled and held voltage as the first detection signal.
17. The motor driving apparatus according to claim 1, further comprising a second timing detector, wherein
said motor driver includes the plurality of series circuits, each of which having a connection point at which the high side and low side switching devices are connected,
said second timing detector detects a timing of a zero cross point of at least one of induced voltages at the connection points during a free-run period, and outputs a detected timing as a timing signal, the free-run period being for which all of the high side and low side switching devices are in an off state in the parallel circuit, and
said periodic signal generator generates a periodic signal whose phase is controlled based on the second detection signal and the timing signal.
18. The motor driving apparatus according to claim 17, wherein said second timing detector detects a timing at which the voltage of the connection point corresponding to said at least one of the induced voltages equals to the voltage at the neutral point of the multiphase motor as the timing of the zero cross point.
19. The motor driving apparatus according to claim 17, further comprising a carrier wave generator which generates a carrier wave, wherein said driving signal generator comprises,
a forcible periodic signal generator which generates a forcible periodic signal whose frequency is constant or changes at a predetermined rate,
a first selector which selects one between the forcible periodic signal and the periodic signal generated by said periodic signal generator,
a first generator which modulates the forcible periodic signal or the periodic signal selected by said first selector with the carrier wave to generate a plurality of first driving signals,
a second generator which generates a plurality of second driving signals with which all of the high side and low side switching devices are turned off,
a second selector which selects the first driving signals or the second driving signals,
a selection controller which controls operations of said first and second selectors,
wherein said second timing detector detects the timing of the zero cross point while said second selector selects the second driving signals.
20. The motor driving apparatus according to claim 19, wherein said selection controller controls the operations of said first and second selectors based on the length of time from starting.
21. The motor driving apparatus according to claim 19, wherein said selection controller controls the operations of said first and second selectors based on a rotation speed of the multiphase motor.
22. A magnetic pole position detector for detecting a magnetic pole position of a multiphase motor by detecting a timing at which a voltage at a neutral point of the multiphase motor equals to a reference voltage, the magnetic pole position detector comprising:
a motor driver which includes a parallel circuit in which a plurality of series circuits are connected in parallel, each of the plurality of series circuits having a high side switching device and a low side switching device connected in series;
a voltage detector which detects the voltage at the neutral point of the multiphase motor during a period, and output a detected voltage as a detection signal, the period being identical to or a part of a period for which all of the high side switching devices orand all of the low side switching devices are in an on state in the parallel circuit; and
a timing detector which detects a timing at which a voltage of the detection signal equals to the reference voltage.
23. A method for driving a multiphase motor which comprises a motor driver including a parallel circuit in which a plurality of series circuits are connected in parallel, each of the plurality of series circuits having a high side switching device and a low side switching device connected in series, the method comprising the steps of:
detecting a voltage at a neutral point of the multiphase motor during a period, and outputs the detected voltage as a first detection signal, the period being identical to or a part of a period for which all of the high side switching devices orand all of the low side switching devices are in an on state in the parallel circuit;
detecting a timing at which a voltage of the first detection signal equals to a reference voltage and outputs the detected timing as a second detection signal;
generating a periodic signal whose phase is controlled based on the second detection signal; and
generating, by using the periodic signal, a plurality of driving signals with each of which a corresponding one of the high side and low side switching devices of the parallel circuit is driven.
24. The method for driving a multiphase motor according to claim 23, in which said motor driver includes the plurality of series circuits each of which having a connection point at which the high side and low side switching devices are connected, the method further comprising the steps of, before the step of detecting a voltage,
forcing each of the high side and low side switching devices to be driven in the parallel circuit;
turning off all of the high side and low side switching devices in the parallel circuit;
detecting a timing of a zero cross point of at least one of induced voltages at the connection points and outputs the detected timing as a timing signal, while all of the high side and low side switching devices are in an off state in the parallel circuit; wherein the periodic signal whose phase is controlled based on the second detection signal and the timing signal is generated.
25. The method for driving a multiphase motor according to claim 24, wherein in the step of detecting a timing of the zero cross point, a timing is detected when a voltage of the connection point corresponding to said at least one of the induced voltages equals to the voltage at the neutral point of the multiphase motor, as the timing of the zero cross point.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1-16. (canceled)
17. Improved non-electrolytic method for metallizing at least part of the surface of a substrate (hereafter called the surface to be metallized) by spraying, using suitable means, of at least one aqueous andor organic aerosol containing at least one metal in cationic (oxidizing) form and at least one reducing agent, capable of converting the metallic cation to metal, of the type of those essentially consisting of:
\u2014b\u2014carrying out the metallization spraying according to a succession of at least two spraying phases, alternating with relaxation phases: (i) setting the duration Dp of the spraying phases between 10\u22122 and 5 s, for the same unit area, and the duration Dr of the relaxation phases between 10\u22122 and 10 s, for the same unit area, the durations Dp and Dr of these spraying and relaxation phases being identical to or different from each other, (ii) and adjusting the spraying flow rate(s), such that the OxRed electronic ratio is comprised between 0.01 and 15, and thus allows the formation of a metallic film which is chemically adherent to the substrate;\u2014c\u2014interrupting the spraying as soon as the intended level of metal deposition is reached, wherein the improvement consists in that it is envisaged:
to implement at least one preliminary stage\u2014ap\u2014of wetting the substrate which involves bringing the latter into contact with at least one wetting fluid, so as to form a fluid film on at least part of its surface;
and, following the wetting\u2014ap\u2014, to commence the spraying according to stage\u2014b\u2014at the latest 60 s, after the end of the wetting.
18. Method according to claim 17, comprising a step \u2014a\u2014consisting in sensitizing andor activating the surface to be metallized.
19. Method according to claim 17, wherein the durations Dp and Dr of spraying and relaxation respectively are defined on the basis of a constant k of metallization intrinsic to each metal such that k=Dp+Dr, comprised between 10\u22121 and 13 S.
20. Method according to claim 17, wherein:
at least part of the metallization spraying is carried out dynamically by moving the spraying means with respect to the substrate so as to carry out a periodic sweep of at least 80%, of the surface to be metallized;
for a given unit area comprised within the sweep zone:
the spraying phase has a duration Dp corresponding to the duration for which the unit area considered is subjected to the spraying of the aerosol,
the relaxation phase which follows this spraying phase has a duration Dr corresponding to the duration of the remainder of the surface to be metallized by the spraying means,
the movement of the spraying means is defined such that:
said spraying means are moved along a path TOA between an point of origin (O) and an arrival point (A) at a spraying movement speed VOA,
as soon as the spraying means reach the point (A), they return to the point (O) at a speed VAO of movement without spraying along a path TAO;
VAO being calculated by taking into account the distance between (A) and (O) and VOA, so that the duration Dr of the relaxation phase of each unit area of the surface to be metallized swept by the spraying means as well as the constant k intrinsic to the deposited metal is as defined above,
this calculation preferably being carried out by a processing and control unit UCC (preferably a microcomputer) controlling the spraying means and a movement system for said spraying means.
21. Method according to claim 20, wherein the substrate is rotated, during at least part of the metallization spraying.
22. Method according to claim 17, wherein the improvement has the following characteristics:
at least part of the metallization spraying is carried out dynamically by moving the spraying means with respect to the substrate andor by moving the substrate with respect to the spraying means so as to carry out a periodic sweep of at least 80%, of the surface to be metallized;
for a given unit area and comprised within the sweep zone:
the spraying phase has a duration Dp corresponding to the duration during which the unit area considered is subjected to the spraying of the aerosol,
the relaxation phase which follows this spraying phase has a duration Dr corresponding to the duration of the sweep of the remainder of the surface to be metallized by the spraying means.
23. Method according to claim 22, wherein the movement of the substrate with respect to the spraying means is a rotation.
24. Method according to claim 17, wherein the duration Dr of the relaxation phase corresponds to the duration for which the unit area considered is not subjected to the spraying of the aerosol.
25. Method according to claim 17, wherein that the temperature of the metallization enclosure is controlled.
26. Method according to claim 17, wherein that the preliminary wetting stage\u2014ap\u2014is carried out by spraying of the vapours of wetting liquid andor of an aerosol of wetting liquid andor by immersion in a bath of wetting liquid, said wetting liquid being optionally heated.
27. Method according to claim 17, wherein the wetting liquid is chosen from the group comprising deionized or non-deionized water, an alcoholic solution comprising at least one alcohol and mixtures thereof.
28. Method according to claim 17, wherein stage b is cyclic, each cycle comprising a spraying phase and a relaxation phase, corresponding to the spraying means moving from (O) to (A) and back and in that the total number of N cycles implemented is chosen as a function of the level of deposition of metal finally sought and the level of deposition of metal obtained in each cycle, this total number of N cycles being comprised between 2 and 5000.
29. Method according to claim 17, wherein that the substrate is rotated during stage\u2014b\u2014, at a speed comprised between 1 and 30 rpm.
30. Method according to claim 17, wherein the path TAO is straight and direct.
31. Method according to claim 28, wherein the formula for calculating VAO is as follows: VAO=AOk\u2212(OAVOA).
32. Method according to claim 28, wherein VOA is comprised between 0.01 and 20 ms.
33. Method according to claim 17, wherein:
the sludges which are produced at the end of the metallization and which contain metal oxides are recovered;
these sludges are filtered;
the retentate is dissolved using at least one strong acid;
the pH of the solution of retentate in the strong acid is increased so as to precipitate the metal hydroxide or successively the different metal hydroxides corresponding to the metal or metals used in the metallization;
the metal hydroxide precipitate(s) are collected separately.
34. Method according to claim 17, wherein this or these metal hydroxide(s) are recycled in the metallization method.
35. Device for the implementation of the method according to claim 17, comprising:
a holder for the substrate to be metallized, optionally equipped with means for rotation of the substrate;
an organ for preliminary wetting the substrate;
a sprayer of the metal in cationic form and reducing agent;
a system for movement of the spraying means, or even of the means of wetting andor of the means of rinsing;
and at least one processing and control unit UCC controlling the spraying means and the system for movement of said spraying means.
36. Device for the implementation of the method according to claim 17, comprising an organ for wetting by spraying of the liquid, in that these wetting organ is movable and this movement of the wetting organ is also controlled by a processing and control unit UCC.