Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The invention relates to a system having a direct-current high-
voltage generator for ceiling electrodes which are to be fastened to the ceilingof a room by means of at least one insulator and serve for the production of
an electrical direct-current field in fixed or movable rooms for human occup-
ancy, the high-voltage generator having a high-voltage terminal and a ground
terminal.
Electroenvironmental installations are known in which a plurality
of electrodes are fastened to the ceiling, each by means of an insulator.
The electrodes are connected together electrically and are supplied through
a limiting resistor from a high-voltage terminal of a high-voltage generator
which is mounted on the wall of the room. The ground terminal is connected
to the walls and floor of the room, so that in the room there is formed an
electrical direct-current field whereby beneficial effects on the persons
within the room can be achieved.
It is also known to operate a direct-current high-voltage generator
standing on the floor by means of the alternating current from the power
mains, a transformer being provided in the high-voltage generator and, on the
secondary side thereof, a voltage multiplier circuit consisting of diodes and
condensers .
In all cases there is needed between the high-voltage generator and
the c~iling electrode a high-voltage supply line which, since it may carry
seVerll thousand volts -- between 2 kV and 15 kV as a rule--depending on the
height of the ceiling and the field strength desired, must be very well insul-
ated. Nevertheless this conductor cannot be prevented from forming a secondary
electrode on which dirt particles deposit themselves to an appreciable extent.
The invention is addressed to the problem of eliminating the diffic-
ulties associated with the high-voltage conductor.
This problem is solved by the invention in that the high-voltage gen-
erator is disposed in the cavity of the insulator and supplied by alternating
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current from the mains, the high-voltage terminal being near the underside of
the insulator and the ground terminal being at or near the top of the insulat-
or.
In this arrangement, the high-voltage lead is reduced to a small
section running within the insulator. The mains voltage feeders running out-
side of the insulator need only to be designed for low voltage and have no
electrode effect of any kind. Through the use of the cavity of the insulator
it is possible to house the high-voltage generator in the comparatively small
interstice between the ceiling electrode and the ceiling, without the danger
of flash-over or short circuits.
It is especially advantageous for the insulator to be in the shape
of a pot open at the top with a hole in the bottom for the electrical connec-
tion between the high-voltage terminal and the electrode. The bottom of the
insulator serves, therefore, simultaneously as a safe, high-voltage lead-
through.`
It is desirable for the hole to accommodate a metal coupling piece,
such as a threaded bushing, for example, serving also for the mechanical
joining of the electrode to the insulator. Thus, when the ceiling electrode
is fastened in place the electrical connection is simultaneously created.
2~ In a preferred embodiment, the high voltage generator is a single
unit fitting within the cavity in the insulator, and having the high-voltage
terminal on the bottom side and the mains and ground terminals on the top.
Such a unit can be manufactured separately. It then needs only to be inserted
into the insulator, the high-voltage terminal being accessible through the
bottom of the insulator and the mains and ground terminals being conveniently
accessible at the top end.
In particular, the high-voltage terminal can have a contact spring
or contact pin which is in contact with a metal connecting piece inserted into
the hole. For the contact at the high-voltage end, therefore, it is sufficient
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simply to insert the high-voltage generator into the insulator-
It is desirable that the high-voltage generato~ have a transfor-
mer and that, on the secondary side thereof, a voltage multiplier circuit con-
sisting of diodes and condensers be provided, which is housed in a grounded
metal housing fitted to the cavity of the insulator and having a relatively
large opening for the high-voltage terminal, the remaining cavities being
filled, preferably with the use of a vacuum, with an insulating composition.
To special advantage, a device for the adjustment of the mains
alternating voltage supplied to the high-voltage generator is provided in
the mains line to the high-vol~age generator. This adjusting device can
be a potentiometer or a voltage divider or an adjustable series resistance,
but preferably a power-saving device using, for example, a silicon controlled
rectifier.
With the adjusting device there can furthermore be associated an
indicator means to indicate the preset direct-current high voltage. Espec-
ially suitable for this purpose is a glow lamp shunted by a condenser and
connected in series with a limiting resistor provided in the high-voltage
generator, the series circuit being connected between the high-voltage side
and the ground. The frequency of the lighting of the glow lamp is a clear
measure of the high voltage.
Furthermore, a switch can be provided for shutting off the glow
lamp, and a shunt resistance, preferably in the form of a Zener diode, which
is in series with the limiting resistor, at least when the glow lamp is
shut off~ These two resistances form a voltage divider which assures that
no more than an acceptable low voltage is present on the side of the limiting
resistance remote from the high-voltage terminal.
If one of the mains conductors is grounded and the corresponding
mains terminal of the high-voltage generator serves simultaneously as a
ground connection, there is no need for a separate ground lead.
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When a plurality of ceiling electrodes is used, it is recommendable
that only one insulator contain a high-voltage generator and that the ceiling
electrodes be connected together electrically.
The invention will now be explained with the aid of the drawing.
Figure 1 is a diagrammatic representation of an electroenvironmentally con-
trolled room with the high-voltage generator of the invention, Figure 2 is
a diagrammatic longitudinal cross sec-tional view taken through an insulator
containing a high-voltage generator, and figure 3 is a circuit diagram of
the high-voltage generator.
A room 1 has grounded defining surfaces 3 (floor, wa]ls, ceiling).
Insulators 4 and 5 each bearing a ceiling electrode 6 are fastened to the
ceiling. In the cavity 7 of the insulator 4 there is inserted a high-voltage
generator 8 whose high-voltage terminal is connected through a mounting screw
9 to the ceiling electrode 6. The rest of the ceiling electrodes are conn-
ected indirectly to the high-voltage terminal of generator 8 by means of
conductors 10 between the adjacent electrodes. A cable 11, which can be
laid under plaster, contains conductors carrying no more than low voltage,
namely two conductors 12 and 13 for the mains ~lternating current, a ground
conductor 14 and a meter conductor 15, which can all be enveloped in a braided
shield 16 (Figure 3). If desired, the ground conductor 14 can be eliminated
if the one mains conductor 13 is grounded (Figure 1~. An adjusting and
indicating apparatus 17 is inserted into the leads of cable 11 and will be
explained further in conjunction with figure 3.
As figure 2 shows, the insulator 4 is in the shape of a pot with
a cylindrical internal cavity 7. On the outer wall there are a plurality of
circumferential ribs 18 and at the upper end there is a flange 19 provided with
holes 20 for mounting screws 21. The bottom of the pot 22 is provided with
reinforcing groo~es 23; it has a central boss 24 containing a threaded metal
bushing 25 to accommodate the screw 9, and a plurality of posts 26 for the
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support of the high-voltage generator 8.
The generator 8 has a metal housing 27 which fits into the cavity
7 and on i~s upper end it has mounting brackets which can be fastened by
means of screws 29 to the insulator 4. The interior of this housing cont-
ains a transformer 30 and a voltage multiplier circuit 31 whose detailed
construction is explained in figure 3. On the housing 27 there is provided
a terminal strip 32 wi~h four terminals 33, 34, 35 and 36 for the conductors
of cable 11. from the terminals 33 and 34 two conductors go to the primary-
side terminals 39 and 40 of the transformer. The terminals 41 and 42 on
the secondary side of the transformer are connected to the inputs 43 and 44
of the voltage multiplier circuit. The input 43 is also connected by a con-
ductor 45 to the housing 27, on the one hand, and to the terminal 35 on ter-
minal strip 32, on the other. The output 46 on the high-voltage side of the
voltage multiplier circuit 31 is connected through a limiting resistor Rl
to a high-voltage terminal 47 in the form of a conical coil spring which,
when the generator 8 is installed in its place, bears upon the metal threaded
bushing 25. The high-voltage output 46 is furthermore connected through a
limiting resistor ~2, a resistor R4 and a conductor 48 to the terminal 36
for the meter conductor. The remaining cavities in the housing 27 are filled
20 with an insulating composition 60.
The voltage multiplier circuit 31 has between the two inputs 43
and 44 a series circuit of a resistor R3, a diode D and a condenser C. The
diode is part of a series of diodes in which an additional condenser C is
connected between the anode of each diode and the cathode of the adjacent
diode. If the transformer has a ratio of 1:6, one obtains from an alternating
current mains voltage of 220 v, i.e., a peak-to-peak voltage of 312 V, a
direct-current high voltage of approximately 12 kV. Often it may be neces~
sary to connect a plurality of diodes or condensers in series in the branches
concerned.
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The alternating mails voltage is fed in through terminals 49 and
50 and through a main switch 51, and its presence is indicated by a glow
lamp 22. Into the mains conductors 12 and 13 there is connected an adjust-
ing means 53, which can be, for example, a silicon controlled rectifier.
By this means the alternating current supplied to the high-voltage generator
8 can be adjusted, and with it the desired direct-current high voltage.
A housing 54 for the adjusting circuit 53 also accommodates an
indicator means 55 which has a glow lamp 56 in series with a switch 57, and
these are by-passed by a condenser Cl. A ~ener diode Z in the housing of
the high-voltage generator is connected in parallel with the condenser Cl
and forms, together with the limiting resistance R2 a voltage divider which
is so designed that no more than 180 volts direct current, for example, can
be present in the meter line 15. How rapidly the condenser Cl will be ch-
arged to the firing voltage of the glow lamp 56 will depend on the high
voltage at the output 46. When the lamp lights the condenser discharges
itself rapidly. Consequently, the frequency of the lighting of the glow
lamp 56 is a measure of the magnitude of the high voltage. The resistor
R4 serves for the protection of the Zener diode Z. It prevents the latter
from being destroyed if it is accidentally connected with the wrong polarity.
The construction represented herein can be modified in many ways.
For example, the insulators 5 can be normal insulators containing a smaller
cavity or none at allO An ion source can also be located in the room 1.
The walls of room 1 can be provided with a covering offering better conduc-
tion than normal masonry. A contact pin can be used insead of the coil
spring 47.
It will be understood that the specification and examples are ill-
ustrative but not limitative of the present invention and that other embodi-
ments within the spirit and scope of the invention will suggest themselves
to those skilled in the art.
