U.S. patent number 3,671,854 [Application Number 05/093,636] was granted by the patent office on 1972-06-20 for contactless galuano-magnetro effect apparatus.
This patent grant is currently assigned to Denki Onkyo Co., Ltd.. Invention is credited to Noboru Masuda.
United States Patent |
3,671,854 |
|
June 20, 1972 |
CONTACTLESS GALUANO-MAGNETRO EFFECT APPARATUS
Abstract
A contactless galvano-magnetro effect apparatus comprised of a
magneto resistance effect device which is provided with a plurality
of electrodes, between which a plurality of resistance yokes are
provided, at least one of the yokes being associated with a
magnetic field applying means which is capable of varying the
condition of magnetic field applied to the resistance yoke.
Inventors: |
Noboru Masuda (Kawaguchi,
JP) |
Assignee: |
Denki Onkyo Co., Ltd.
(N/A)
|
Family
ID: |
22239978 |
Appl.
No.: |
05/093,636 |
Filed: |
November 30, 1970 |
Current U.S.
Class: |
323/368; 338/32H;
257/E43.004 |
Current CPC
Class: |
H01L
43/08 (20130101) |
Current International
Class: |
H01L
43/08 (20060101); G05f 007/00 () |
Field of
Search: |
;338/12,32H,32R ;323/94H
;324/45,46 ;307/309 ;335/1,2 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: C. L. Albritton
Attorney, Agent or Firm: James E. Armstrong Ronald S.
Cornell
Claims
1. A contactless galvano-magnetro effect apparatus comprised of a.
a magneto-resistance effect device having an endless circular
shape; b. conductive electrodes which are arranged to cross the
surface of the device at at least two positions so that the device
is divided into at least two resistance yokes; c. a magnetic field
applying means which is positioned opposite to the device so that
the flux density of the magnetic field applied to at least one
resistance yoke can be varied; and d. connections associated with
the electrodes for an external input power supply and load, whereby
the resistance value of the resistance yoke can be varied with the
variation of the flux density of the magnetic field.
2. A contactless galvano-magnetro effect apparatus according to
claim 1, wherein at least one conductive segment, which crosses the
surface of at
3. A contactless galvano-magnetro effect apparatus according to
claim 2, wherein a plurality of conductive segments are arranged on
the resistance yoke so that the distances between adjacent
conductive segments are successively decreased from one electrode
in the direction of the other
4. A contactless galvano-magnetro effect apparatus according to
claim 1, wherein at least one resistance yoke, the width of which
is gradually
5. A contactless galvano-magnetro effect apparatus according to
claim 1, wherein a circular magnetro-resistance effect device is
provided with three electrodes and is divided into three resistance
yokes, two of the electrodes being connectable between the
remaining intermediate electrode and the power supply, so as to be
parallel with one of two resistance yokes which has the
intermediate electrode at one end, and a magnetic field applying
means which is positioned opposite to one of two resistance
6. A contactless galvano-magnetro effect apparatus according to
claim 5, wherein the flux density of the magnetic field applied to
the two resistance yokes which are divided by the intermediate
electrode is
7. A contactless galvano-magnetro effect apparatus according to
claim 1, wherein a circular device is provided with four electrodes
and is divided into four resistance yokes, the power supply being
connected to two of the four electrodes which extend opposite from
each other, the load being connected to the remaining two
electrodes, and the resulting bridge circuit, which consists of the
four resistance yokes, is unbalanced by varying the flux density of
the magnetic field applied to one of the
8. A contactless galvano-magnetro effect apparatus according to
claim 7, wherein the flux density of the magnetic field applied to
the two resistance yokes corresponding to the two opposite yokes of
the bridge
9. A contactless galvano-magnetro effect apparatus according to
claim 7 wherein the load connected to the bridge circuit is a
resonance circuit consisting of a variable capacity diode, which
varies its capacity in accordance with voltage, and an inductance
coil and the bridge circuit are controlled so that the output
characteristics gradually increase or
10. A contactless galvano-magnetro effect apparatus according to
claim 9, wherein a gate device and a diode for the gate with Zener
characteristics are series-connected between the intermediate point
of the coil of the resonance circuit and the output terminal of the
bridge circuit, the gate device operating to cause the diode for
the gate to be conductive and the intermediate point of the coil
being short-circuited to the output terminal of the bridge circuit
when the flux density of the magnetic field
11. A contactless galvano-magnetro effect apparatus according to
claim 10, including a rotary shaft wherein a rotary magnet,
energized in the direction of thickness, is provided with at least
one non-energized portion in the radial direction and rotates in
parallel with the device, a rotary plate, to which the magnet is
fixed, is mounted to the same rotary shaft, and a fixed support
plate is provided with at least one galvano-magnetro effect device
as the gate device and is arranged opposite to the rotary plate,
the magnetic flux from the magnet on the rotary plate being
concentrated onto the gate device of the support plate when the
non-energized portion of the rotary magnet comes to a position
opposite to
12. A contactless galvano-magnetro effect apparatus according to
claim 1, wherein a rotary magnet is energized in the direction of
thickness and is provided with at least one non-energized portion
in the radial direction so that the non-energized portion moves
opposite to the resistance yoke of the device.
Description
Conventional variable resistors and switching apparatus are
constructed such that their contact pieces are forced to contact
corresponding resistance portions and contacts. Consequently, such
apparatus are disadvantageous because wear due to friction and
noise, such as chattering, etc. are caused by repeated contact.
The present invention is intended to provide a contactless
galvano-magnetro effect apparatus capable of eliminating these
problems.
SUMMARY
The present invention provides a galvano-magnetro effect apparatus
comprised of an endless circular type (including the polygonal
type) magneto resistance effect device, electrodes made of
conductive material which are formed so that the electrodes cross
at least two portions of the device to divide the device into at
least two resistance yokes, a magnetic field applying means which
is arranged to oppose to at least one resistance yoke so that the
condition of the field being applied is varied, and external input
power supply and load circuits which are connected to the
electrodes.
The present invention is illustrated in detail by the accompanying
drawings whereof:
FIG. 1 is a front view of a contactless galvano-magnetro effect
apparatus of the present invention;
FIG. 2 is a front view of the magneto resistance effect device used
in the apparatus;
FIG. 3 is the circuit diagram of the apparatus illustrated in FIG.
1;
FIG. 4 is a front view of another embodiment of the apparatus of
the present invention;
FIG. 5 is the circuit diagram of the apparatus illustrated in FIG.
4;
FIG. 6 is a front view of another embodiment of the apparatus of
the present invention;
FIG. 7 is a front view of the galvano-magnetro effect device to be
used in the apparatus shown in FIG. 6;
FIG. 8 is a cross-sectional side view of the apparatus shown in
FIG. 6;
FIG. 9 is a front view of another embodiment of the apparatus of
the present invention;
FIG. 10 is a side view of the apparatus shown in FIG. 9;
FIG. 11a and 11b are front views of embodiments of the magnetic
field applying means which is used in the apparatus of the present
invention;
FIGS. 12, 13 and 14 are front views of embodiments of the magneto
resistance effect device used in the apparatus of the present
invention; and
FIGS. 15 and 16 are the circuit diagram of the apparatus shown in
FIG. 6.
DETAILED DESCRIPTION
Referring to FIGS. 1 to 3, there is shown base plate 2 made of a
magnetic or non-magnetic material which is fixed at chassis 1,
magneto resistance effect device 3 (hereinafter referred to as the
"device") made of InAs, InSb, Ge, Si, etc. which is fixed in the
form of an endless circle to the surface of base plate 2 by
photo-etching, two electrodes 4 which are oppositely arranged in
the radial direction of the device 3 so that the electrodes treated
by means of metalization cross the surface of the device, a
plurality of conductive segments 5 which are arranged at equal
intervals on one of two resistance yokes 31 and 32, which are
divided by two electrodes 4 and are formed so as to cross the
surface of the device in the same manner as the electrodes, a
semicircular magnet 7 which opposes the device 3 with a clearance
separating the magnet and the device, the magnet being forced to
rotate by rotary shaft 6 while being energized in the direction of
its thickness, and external input power supply 8 and external load
9, which are connected to the electrodes.
Conductive segments 5 need not always be provided. The apparatus as
shown is, however, advantageous because, if conductive segments 5
are provided, the plurality of resistance surfaces 3r of the
resistance yoke separated by the conductive segments operate as
independent elements; therefore, the resistance yokes can be
operated in the same manner as a number of magneto-resistance
effect devices which are series-connected.
The conductive segments can be provided at unequal intervals and
can be arranged so that the intervals are gradually decreased. If
thus arranged it is possible to make the resistance variation
characteristics of each resistance surface 3r uneven by varying the
ratio L/W (L is the length and W is the width of each resistance
surface 3r) and, accordingly, the resistance variation
characteristic of resistance yoke 31 can be set as desired.
The contactless galvano-magnetro effect apparatus as described
above operates as follows: when magnet 7 is rotated, the areas of
resistance yokes 31 and 32 of device 3 positioned opposite to
magnet 7 vary, the resistance value of resistance yokes 31 and 32
vary, and the voltage to be applied to load 9 varies.
Hereupon, if conductive segments 5 are arranged on one of the
resistance yokes 31 and 32 as shown, the apparatus operates
advantageously because the resistance variation of resistance yoke
31 increases with the rotation of magnet 7 and it is possible to
give linearity to the output voltage characteristic by selecting
the distance between conductive segments 5 of resistance yoke
31.
FIGS. 4 and 5 illustrate the apparatus comprised of three
resistance yokes 31, 32 and 33 which are made up by providing three
electrodes 4 at device 3.
In this embodiment, magnet 7, which is used as the magnetic field
applying means, is sector-shaped in accordance with the length of
the resistance yoke so that the magnetic flux is alternately
applied to two resistance yokes 31 and 32. Load 9 is connected to
power supply 8 so that the load is parallel-connected to resistance
yoke 31 of device 3.
The apparatus of this embodiment is constructed as mentioned above.
If magnet 7 is alternatively positioned opposite to two resistance
yokes 31 and 32, the voltage applied to load 9 varies.
Hereupon load 9 can be connected to power supply 8 so that the load
is parallel-connected to resistance yoke 32. The magnet can be
positioned so as not to alternatively oppose both resistance yokes
31 and 32 and can be arranged so that the magnetic flux is applied
to only one of resistance yokes 31 and 32, one end of which is the
electrode connected to intermediate output terminal 10.
In this case, the apparatus is constructed so that magnet 7 is
forced to approach or depart from resistance yoke 31 or 32 to vary
the density of magnetic flux applied to the resistance yoke.
Furthermore, it is desirable to provide conductive segments 5 on
resistance yokes 31 and 32 which are opposite to magnet 7 as
mentioned above. Thus, the resistance variation characteristic of
the resistance yoke can be set according to its intended use.
The magnetic field applying means can be a means to increase the
resistance value of a variable resistance yoke, for example,
resistance yoke 31, to a value greater than that of other
resistance yokes by applying the magnetic flux to resistance yoke
31 or alternatively, it can be a means to decrease the resistance
value of the variable resistance yoke to a value lower than that of
other resistance yokes.
FIGS. 6 to 8 illustrate the apparatus provided with four resistance
yokes 31, 32, 33 and 34 which are obtained by dividing device 3
with four electrodes 4.
Each resistance yoke is designed so that its resistance value is
equal to that of other resistance yokes. In this case, power supply
8 is connected to two electrodes which are oppositely arranged in
the radial direction and load 9 is connected to the other two
electrodes.
Accordingly, in this embodiment, resistance yokes 31, 32, 33 and 34
form a bridge circuit. In this embodiment, if the condition of the
magnetic field, such as, for example, the magnetic flux density,
which is applied to resistance yoke 31, varies, the resistance
value of resistance yoke 31 varies and the voltage is applied to
load 9.
The voltage applied to load 9 gradually increases and decreases if
the resistance value of resistance yoke 31 is gradually increased
or decreased. Accordingly, if load 9 is made as a resonance circuit
consisting of variable capacity diode 91 such as, for example, a
varactor diode, the capacity of which varies with the voltage, as
shown in FIG. 6, the resonance frequency of the resonance circuit
can be varied with the resistance variation of resistance yoke 31
and the apparatus of the present invention can be used as the tuner
of a television set.
In this case, a method to change the condition of the magnetic
field which is applied to resistance yoke 31 is optional. It is
desirable to use the magnetic field applying means which is
provided with disc-type magnet 7 which is energized in the
direction of thickness, is rotatably supported by shaft 6 and is
provided with non-energized portion 71 in the radial direction, as
shown in FIGS. 6 and 8.
When using this magnet 7, it is necessary to vary the resistance
value of resistance yoke 31 along with movement of non-energized
portion 71 opposite to resistance yoke 31 and therefore it is
necessary to arrange a number of conductive segments 5 on
resistance yoke 31 so that the distances between conductive
segments 5 becomes narrower as shown in FIG. 7.
When non-energized portion 71 of magnet 70 moves along resistance
yoke 31, the total area of resistance surfaces 3r of the device
which is opposite to non-energized portion 71 varies and
accordingly, the resistance value of resistance yoke 31 gradually
increases or decreases.
Hereupon conductive segments 5 can be provided on other resistance
yokes 32, 33 and 34 of device 3 as desired. Thus, the resistance
value of all resistance yokes can be even regardless of the length
of resistance yoke under a special condition in which the magnetic
flux density is being applied; for example, every resistance yoke
is fixed. However, in this embodiment, magnet 7 has non-energized
portion 71; therefore, the apparatus should be designed so that the
bridge circuit is balanced when non-energized portion 71 is
positioned at a specific idle position.
This can be achieved by widening electrode 4 and by arranging it so
that the bridge circuit is balanced when non-energized portion 71
is forced to oppose to said electrode. In addition, it is possible
to apply another method; that is, the idle point of non-energized
portion 71 can be set at one of the resistance yokes 32, 33 and 34
(excepting resistance yoke 31) so that the resistance value
ofresistance yoke 31 is equal to that of other resistance yokes
when the resistance yoke is opposed to non-energized portion
71.
Therefore, conductive segments 5 can be provided on every
resistance yoke as shown FIG. 7 and the resistance value of a
resistance yoke can be relatively set.
When arranging rotary magnet 7 to oppose to the device 3, it is
desirable to fix plate magnet 72, which is energized in the
direction of thickness at the rear surface of base plate 2 as shown
in FIG. 8, so that thepolarity of the device side of the plate
magnet 72 is different from that of the device side of the rotary
magnet 7. Thus, the magnetic field applied to device 3 can be even
between both magnets 7 and 72.
The magnetic field applying means may be made so as to vary the
magnetic flux density applied to a specified resistance yoke as
mentioned above. However, when rotary magnet 7 as shown in FIG. 6
is used, this magnetic flux density applied to resistance yoke 31
along which non-energized portion 71 moves while being kept
opposite to the resistance yoke does not vary; accordingly, in this
case, it is necessary to arrange a number of conductive segments 5
at different intervals so that the resistance value of resistance
yoke 31 varies with movement of the magnetic field. In other words,
the magnetic field applying means can vary the situation and
strength of the magnetic field applied to specified resistance yoke
31.
Because the apparatus of this embodiment is constructed as
described above, it can be used in various types of electric
equipment. When using it as a tuner, as mentioned before, the
resonance frequency is varied only with variation of the capacity
of the diode; accordingly, the apparatus is disadvantageous because
a substantially high voltage should be applied to the diode in the
channel of the high frequency side.
FIGS. 9 and 10 illustrate a tuner which raises the resonance
frequency by reducing the inductance of the resonance circuit.
In this embodiment, gate device 93, such as a Hall effect device,
is connected to the intermediate portion of coil 92 of resonance
circuit 9, and diode 94 for the gate, which has the characteristics
of the Zener diode, is connected to gate device 93.
Gate device 93 is set so that it operates when the tuner selects
the channel of the high frequency band and applies the operating
voltage to the diode. Diode 94 for the gate is set so that it
becomes conductive when the gate device 93 operates and the
intermediate point of the coil 92 is short-circuited to electrode 4
at the output side of device 3.
The means to actuate gate device 93 is optional. A satisfactory
operation of the apparatus can be obtained by fixing rotary plate
61 to shaft 6 so that it rotates together with magnet 7 as shown in
FIG. 10, arranging magnetic material support plates 11 which are
fixed at chassis 1 to be opposite in parallel on the rotary plate
61, fixing the Hall effect device at support plate 11 as gate
device 93 and mounting magnet 73 on the part of rotary plate 61 so
that the magnetic flux from magnet 73 is concentrated onto Hall
effect device 93 when the tuner selects the channel of the high
frequency band.
Thus, other galvano-magnetro effect devices can be used as gate
device 93; for example, the magneto-resistance effect device can be
also used.
Hereupon, in the bridge circuit consisting of device 3, only
resistance yoke 31 can be used as the variable resistance yoke as
shown in FIG. 15. Depending on the intended use of the apparatus,
resistance yokes 31 and 33 (or 32 and 34) in opposite positions can
be used as the variable resistance yokes as shown in FIG. 16. Thus,
it is advantageous because the bridge circuit can be greatly
unbalanced.
Non-energized portion 71 of rotary magnet 7 can be made by notching
magnet 7 as shown in FIG. 6 or by closely contacting the
non-magnetic piece to the notched portion as shown in FIG. 11a.
If non-energized portion 7 is made by loosely contacting the
non-magnetic piece to the notched portion, two or more
non-energized portions 71 and 71' can be formed on one magnet 7. By
this means a convenient rotary magnet to be used in the apparatus,
for example, as shown in FIG. 16, can be made.
Hereupon resistance yoke 31, used as the variable resistance yoke,
can be lengthened by providing conductive segments 5 on the
resistance yoke.
FIGS. 12 to 14 illustrate device 3 in which resistance yoke 31 is
made longer than other resistance yokes 32, 33 and 34.
The width of resistance yoke 31 of device 3 shown in FIG. 12 is
gradually narrowed in the direction of the opposite electrode.
Since the area and shape of resistance surfaces 3r of resistance
yoke 31 are different from each other, even though the distances
between conductive segments 5 of device 3 are fixed, the resistance
value of resistance yoke varies with movement of non-energized
portion 71 of rotary magnet 7 which is forced to oppose resistance
yoke 31.
In this embodiment, the shape of resistance surfaces 3r of
resistance yoke 31 can be freely changed with the distance between
conductive segments 5; for example, the sensitive characteristic to
magnetic flux density of the wider resistance surface can be
enlarged by setting ratio L/W of length L to width W to 1/4,
whereas the sensitive characteristic of the narrower resistance
surface can be reduced by setting the ratio L/W to 1/4-n.
According to this embodiment, because the resistance variation
characteristic can be freely controlled depending on the shape
variation resistance surface 3r, the output characteristic of the
device can be determined to meet the intended use, for example, to
have linearity.
In the device shown in FIGS. 13 and 14, resistance yoke 31 is made
long in accordance with the length of conductive segments 5 or the
area and distance. The devices of the above embodiment have the
same advantages as said device shown in FIG. 12 and all resistance
yokes 31, 32, 33 and 34 can be made in the same width; accordingly,
the length of resistance yoke 31, which is used as the variable
resistance yoke, can be freely determined and the device 3 in the
same shape can be used for many purposes merely by changing the
arrangement of the electrodes.
Since the apparatus of the invention does not require mechanical
contacts, it is not subject to poor contact due to wear of the
contacts or to generation of noise, such as chattering. Since
resistance yokes 31, 32, 33 and 34 are made of the same material,
the thermal characteristics of the resistance yokes are equal;
accordingly, the bridge circuit will not be unbalanced because of a
rise in temperature if device 3 forms a bridge circuit. Therefore,
this type of the apparatus requires no separate temperature
compensating means and there are no problems even if a material of
low quality thermal characteristic is used. Thus, the cost of
production can be reduced.
If conductive segments 5 are formed on a resistance yoke or yokes,
the output characteristics of the device can be freely determined
and the resistance yoke which is used as the variable resistance
yoke can be long; for example, the moving stroke of non-energized
portion 71 can be long when rotary magnet 7 as shown in FIG. 11a is
used.
Since the resistance value and number of resistance yokes can be
determined depending on the arrangement of a plurality of
electrodes 4, a device with different patterns of uses and output
characteristics can be easily made.
* * * * *