JPS5836159A - Tachometer generator - Google Patents

Abstract

PURPOSE:To enable the reverse connection of an output voltage in a tachometer generator by electrically insulating the controller of an electronic switch forming a rectifier in each electronic switch. CONSTITUTION:4 phase AC outputs are respectively produced from generating coils 1a-1d, and are sequentially connected by switching electronic switches 1A-1D, thereby obtaining a DC output voltage at Vout. The switching of the switches 1A-1D is performed by detecting the rotating position of a rotor which is made of a permanent magnet by Hall elements 2a-2d which are disposed between the coils. In other words, the alternating signals of the elements 2a-2d are applied through emitter followers 509-512 to between the sources and the drains of the switches 1A-1D. A power source of the followers 509- 512 is supplied by insulation through a DC/AC converter 517, an insulating transformer 6b and AC/DC converters 513-516. In this manner, Vin and Vout are electrically insulated, thereby enabling the reverse connection of the Vout.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a rotating body position detection system that controls a rectifier on the output side of a speedometer generator mounted on a rotating body.

Conventionally, as a means of obtaining a DC output voltage proportional to the rotation speed without using a brush in a speedometer generator, a multi-phase AC output generator is used, and the output of each phase is sequentially switched and connected to create a DC output voltage. A method is being used.

FIG. 1 is a route map of a conventional device.

1a to 1d are power generation coils (the mark indicates the start of winding of the coil), 28 to 2d are Hall He (generators) that detect the position of a rotating body consisting of a permanent magnet (not shown), and SW is an electronic switch (IA .about.ID is turned on and off sequentially), AMP is a DC amplifier, and ■ is a generated voltage proportional to the speed of the rotating body.

The internal power supply of this device is +V power supply and -vIE source, and the electronic switch (MO8) is supplied from another V, , V power supply, and the withstand voltage of the switch is usually +V.

The voltage between -1 and 3 is about 15V, and switching is only possible up to ±7.5V.

In this method, (1) Since the withstand voltage of the electronic switch SW is low, it is necessary to use an amplifier AMP for amplifying the DC output voltage.

Therefore, when the gate control circuit is not insulated, the gate-source breakdown voltage of the electronic switch (for example, MOS-FET) becomes the breakdown voltage of the element. Conventional brushed speedometer generators are often used at around 7 V/1000r, p-m, and ±2 when used at 3000r, p,m.
It is necessary to control the output voltage of 1V.

(2) The disadvantage of using an amplifier is that the offset voltage and temperature drift of the amplifier are added to the output voltage, which deteriorates the accuracy of the output voltage. In other words, since an offset voltage is generated, for example, even though the speedometer generator is stopped, it is still rotating because voltage is being generated.

■ To solve the above problem, it is necessary to use an expensive amplifier, which increases the cost.〇■ Output voltage V.

Since one side of ut is Ov, in a conventional speedometer generator, if the output voltage is connected in reverse as shown by the dotted line on the right side of FIG. 1, the output voltage will be short-circuited and no output will be output.

■ DC output voltage V even if amplifier AMP is used. ut is ±
Amplifiers that can obtain high voltages such as 3ov are difficult to integrate and have high voltages (generally used linear ICs are ±1
(Many have a power supply voltage of 5V).

There was a drawback.

Here, the present invention is a means to solve these problems, that is, to electrically insulate the control section of the electronic switch SW of the switching section to direct current. ■ A high output voltage is achieved. ■ Output voltage V. ut can be connected in reverse, and (1) Since the amplifier AMP is not used, there is no offset voltage, etc., and the output voltage accuracy is improved.

The purpose is to provide a speedometer generator having the following characteristics.

Fig. 2 is a basic circuit configuration diagram of the present invention, Fig. 3 is a front view of a power generation section in an embodiment of the present invention, Fig. 4 is a side sectional view of the power generation section and detection section, and Fig. 5 is a A block diagram showing the circuit configuration and FIG. 6 are signal waveform diagrams of various parts during operation.

In Fig. 2, detection elements (Hall IC) 2a to 2d
The position detection signal of the rotating body from the IA is transmitted through the control circuit section E, which is insulated from the input power source.

The electronic switches for IB, IC, and ID are turned on and off.

In FIG. 3, 1 is the rotating shaft of the speedometer generator, and 2 is the rotor, which is composed of a magnet 3 and a ballsche 4. 5
is a fixed magnetic pole and yoke, and the electric phase coil is 360γ in electrical angle.
n They are arranged in a staggered manner, and Figure 3 shows 2 balls,
The case of 4-phase, annular winding is shown. Further, as the material of the yoke 5, in order to reduce the distortion of the output voltage waveform due to the eddy current loss caused by the rotor 2, a layered silicon steel plate or a ferrite core is used.

The rotor 2 mounted on the rotating shaft 1 shown in FIG. 4 and the fixed magnetic pole/yoke 5 form a power generation section 4A, and the rotor yoke/shield plate 7 shields the magnetic field on the right and left side of the area. , the magnetic flux of the magnet 8 fixed on the rotating shield plate 7 constitutes the detection section 411 of the Hall IC.
The position of the rotor 2 is detected by passing through the hole ICs 2a, . . . fixed to the support plate 9.

In Fig. 5, 4a to 4h are MOS-FET transistors 1et.
al O:clde Sem1conductor-F
D is drain, S is source, G is gate, 3a to 3d and 501
~508 is a resistor, 509-512 is a transistor, 6a
is a DC to DC converter that electrically isolates its input side and output side, 513 to 516 are also current to DC converters, 6b is an isolation transformer, and 517 is a DC to AC converter,
Both ends 5a of load resistors 3IL-3d of transistors 509-512.

5a' to 5d and 5d' are 5a and 5a between the source and gate of the cascade-connected MOS-PET, respectively.
'~5d, 5d' are connected.

The operation of this embodiment will be explained with reference to the wiring diagram in FIG. 5 and the voltage waveform time chart in FIG. 6.

When the rotating shaft 1 rotates, 1a shown in FIGS. 61 to 64
An alternating voltage of output voltage ~1d output voltage is generated, and the wave height [,
~E is proportional to the rotation speed. Detection part hole 1c2a~
2d is operated by the magnet 8 of the rotor, and the output terminals 5a-5m' to 5d-5d' of the transistors 50 and 512 are operated by the magnet 8 of the rotor.
A rectangular wave ω is generated at the end, and a voltage is applied between the gates G and S of the electronic switches (vertical MO8-FET) 4a to 4h.

Vertical FIT is optimal as an element with low ON resistance, but if the resistance of coils 1 & ~ 1d is large, M
OS-FIT and J-FET can also be used. The electronic switches IA to ID are turned on and off by this control signal field to 68, and the voltages of the output voltages Ea to Ed are switched to the DC voltage V.
. Get uP.

However, at the time of switching, the timing of the waveform width of the control signal ω is set so that the electronic switch in charge of the voltage of the next phase is turned on and then the electronic switch of the previous phase is turned off. That is, the output voltage V when switching. ut is Ov
Switching should be done while overlapping to avoid this.

By the way, the feature of the present invention is that these electronic switches IA to I
It is in the control circuit that controls D.

Each hole 1c2a to 2dK is detected and the electronic switch IA
~ID control signal 65 to be added between G and source S
~68 is a DC → DC conversion circuit (if the input power source is AC, a current conversion → DC conversion circuit is applied for the pressure) 6a
Since the electronic control circuit power supply is supplied to the electronic switches IA-ID, the control signals of each electronic switch IA-ID are completely electrically isolated and independent.

Switching, electronic switch IA~ID both 44a + 4
The drains D to D of each of bs4c, 4d, 4e, 4f, and 4g+4h are insulated from the input imVin.

Therefore, which of the two terminals of the output voltage 'vout is connected to O
Even if connected to V, the output voltage will not be short-circuited as in the conventional case.

Vertical MO8-PET has a high withstand voltage of 60 V or more between the drain D and source S due to the characteristics of the element, but on the other hand, the withstand voltage between the gate G and source S is as low as 15 V or more, phantom V. One of the drawbacks of this invention is that
If the control signal applied between the source S and the input source S is insulated from the input source S, the withstand voltage between the drain D and source S becomes the withstand voltage of the element, and it becomes possible to turn on and off a high output voltage signal. Since the output voltage can be increased to a high level, the need for an amplifier becomes inconvenient as in the conventional case, and the output voltage does not fluctuate due to temperature or the like.

The vertical MO8-FETs of the electronic switches IA to ID used in this example have a structure in which diodes 71 and 72 are connected in parallel between the drain and low source 8, as shown in FIG. Therefore, when the polarity of the output voltage changes in the rotational direction as in the present invention, the elements 4m+4b, . . . are connected in series and used. In addition,
The reason why the signal output applied between G and source S is configured by the input floor of transistors 509 to 512 is to discharge the electric charge accumulated in the stray capacitance between gate G and source S of the element to resistors 3 and ~3d. This is to improve the switching speed of the element, and 3a to 3d also serve as discharge resistors.

FIG. 8 is a book diagram of another embodiment of the present invention.

The control circuit E' is electrically insulated from the input power supply vi□, and is divided into two groups of electronic switch sections 91 and 92.
9, 2 and 2' are controlled to be turned on and off at the same time.

Therefore, when the rotor '2 shown in FIG. 3 rotates eccentrically, the voltages generated in the coils 1a to 1d differ, resulting in an increase in the ripple content of the speedometer generator. In other words, the most important characteristic of a speedometer generator is a low ripple content, which is contrary to this. As a countermeasure against this, as shown in Fig. 8, the coils 1a and jc,
lb and 1d? If the windings are connected in reverse polarity to form a two-phase winding, 72 sets of electronic switches are prepared, and the two-phase full-wave rectification is controlled, a speedometer generator with a small EL content can be obtained.

FIG. 9 is a route map of still another embodiment of the present invention.

As one measure to reduce ripples in the output voltage when the rotor 2 is eccentric, the coils 1a to 1d are bifilarized, and the control circuit E of the electronic switches IA to ID is electrically connected to each electronic switch IA to ID. Eri for insulating,
The following effects can be obtained.

- The withstand voltage of the electronic switch SW is improved, and a speedometer generator with high output voltage can be obtained.

In other words, since it is electrically insulated, the signal voltage necessary for control is the voltage between the gate and the saw 78 (vertical MO&-FET).
17) Case C + 10 V K te, t y, 0VIC
and turn off. ), drain 9 - source 8
If you use one with a withstand voltage of 69V, you can switch a voltage of 60V.

■ Since a high output voltage can be obtained, an output voltage amplifier is no longer required, and the conventional differences related to the amplifier AMP, such as temperature drift voltage and offset voltage, are eliminated, and the detection accuracy of the speedometer generator is improved.

In addition, since the amplifier AMP for high output voltage has been a cause of cost increase, this will also lead to cost reduction.

(2) Since both terminals of the electronic switches IA to ID are electrically insulated, the output voltage will not be short-circuited no matter which output voltage terminal Ov is connected.

(2) Conventionally, switching noise was superimposed on the output voltage due to the stray capacitance between the gate G and source S of each electronic switch, but since it is electrically insulated, switching noise is eliminated.

[Brief explanation of the drawing]

Fig. 1 is a route diagram of a conventional device, Fig. 2 is a basic circuit diagram of the present invention, Fig. 3 is a front view of a power generation section in an embodiment of the present invention, and Fig. 4 is a construction of the power generation section. 5 is a block diagram showing its circuit configuration, FIG. 6 is a signal waveform diagram of each part during its operation, and FIG. 7 is an electrical configuration of each electronic switch in this embodiment. 8 is a block diagram of another embodiment of the present invention, and FIG. 9 is a route map of a further embodiment of the present invention. 1...Rotating axis, IA~LD, IA'~ID'SW...
・Electronic switch, la~2d...Generating coil, 2...
・Rotor, 2a-2d... Hall IC (position detection generator), 3... Magnet, 31-36, 501-
508...m resistance, 4...Paulsch, 4h~4h・
・MOS-FET, 5 ・Fixed magnetic pole and yoke, 5a-5d to 5d-5d ・Electronic switch input terminal, 509-512 ・Transistor, 513 to 516
... AC 1 DC converter, 517 ... DC → AC converter, 6 & ... DC → DC converter'a (for insulation), 6b.
... Insulation transformer, 7... Rotor yoke/shield plate, 8... Magnet, 9... Hall IC holding plate. Applicant's agent Kiyoma Inomata 7th figure Horse 8th figure Bekkyou circuit Iku E' Horse 9th figure

Claims (1)

[Claims] A power generation section consisting of a rotor made of a permanent magnet, a yoke that also serves as a fixed magnetic pole around which a coil is wound, and a detection section that detects the rotation angle of the rotating shaft to send out a signal to sequentially switch the AC output of this power generation section. and a rectifier that switches the alternating current voltage of each coil of the power generation section according to the output of the power detection section to obtain an output voltage proportional to the rotational speed of the rotating shaft. A speedometer generator characterized in that the control section of the electronic switch is electrically insulated for each electronic switch.