DE2751237A1 - INSECT DISTRIBUTION DEVICE - Google Patents

Description

THORN DOMESTIC APPLIANCES (ELECTRICAL) LIMITED,
London / Great Britain

Insect vurti i loosening device

The invention relates to an insect killing device.

The inventive insect eradication device has a
hollow grid structure into which an insect attractant can be introduced, and at least one first electrode and
at least one second electrode and a device for applying a high voltage to the first and the second electrode, comprising a capacitor which is connected in parallel with the first and the second electrode and stores an electrical energy which in use is via one of the first and the second electrode bridging insect is broken down.

When an insect bridges the electrodes, the energy that destroys it is drawn from the capacitor. This can result in
a high-voltage source can be dispensed with, which charges the capacitor to deliver this current. The one in the condenser
This is because stored energy can build up relatively slowly
and are then broken down extremely quickly by an insect bridging the electrodes.

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Although the capacitor could be charged from the AC mains, the charging is preferably carried out by means of a battery-powered DC-to-DC converter. In order to obtain a sufficiently high voltage at the electrodes, preferably 2 to 3 kV, without drawing excessive current from the batteries and without having to make the transformer too large, the converter has a Cockcroft and Walton voltage multiplier circuit .

Since attracting fragrances basically only act on very specific insect species , it may be desirable to have an attractant available that acts on a large variety of insect species. An ultraviolet lamp or any other suitable light emitting lamp is one such general insect attractant and can be placed within the grid structure. Gas discharge tubes that can be operated by the voltage converter can serve as ultraviolet light sources.

In one of the embodiments described below, the voltage converter has an oscillator which is connected to a transformer stepping up the voltage and the frequency of which changes as a function of the voltage applied to the output capacitor in such a way that the capacitor is charged quickly after it has been discharged, while at other times the battery is only used minimally. Although such an arrangement has proven useful in practical use, it has some disadvantages. The frequency of the pulses with which the transformer is operated changes essentially as a function of the state of charge of the output capacitor. This means that the transformer is not always operated with a pulse frequency at which

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The energy transfer is optimal, so that the speed, with which the energy is drawn from the battery is higher than it would otherwise be. In addition, the lamplight noticeably depending on the state of charge of the output capacitor change. Therefore, according to a further embodiment the duty cycle (mark-to-space ratio) the pulse train with which the transformer is operated changed in such a way that the pulse duration (marking duration) increases, when the battery voltage is absent, whereby the voltage applied to the capacitor is at least approximately at a constant Value is held.

By changing the duty cycle as a function of the battery voltage, it is possible to increase the current from the battery minimize, while at the same time ensuring that a possibly provided insect-attracting high-voltage lamp is operated in the sense of a sufficient light emission. The circuit can be constructed in such a way that the frequency of the pulse train remains at least approximately constant, while the duty cycle increases, so that the transformer to is controlled at approximately the same frequency at all times in order to obtain optimum efficiency. The increase in Pulse duration with decreasing battery voltage ensures that the output voltage at the output capacitor is at least remains roughly constant, so that it is not necessary to display the voltage on the capacitor.

A suitable circuit arrangement for this includes an astable one Multivibrator with a pair of cross-connected transistors, each of which has a timing element in the form of a resistor and a capacitor is assigned, the voltage excursions of the capacitor connected to the one transistor, which come from another switching transistor, are limited by a diode, whereby the switch-off

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duration of the first transistor is extended when the battery voltage decreases. This changes the duty cycle in the desired manner.

Further advantages, details and features of the invention emerge from the following, with reference to the enclosed Drawing following description of several exemplary embodiments.

In the drawing show:

Figure 1 is a cross-sectional view of an am; guide shape according to the invention;

FIG. 2 shows a circuit diagram of the voltage converter circuit which is used in the embodiment of FIG will;

FIG. 3 shows a plan view of a second embodiment according to the invention;

Figure 4 is a cross-sectional view taken along line 2-2 of Figure 3;

Figure 5 is a cross-sectional view of the battery compartment of the device;

Figure 6 is a cross-sectional view taken along line 4-4 of Figures 3 and 4

FIG. 7 shows a circuit diagram for the device according to FIGS. 3 to 6.

The insect repellent device shown in FIG. 1 has a lower part 2 made of plastic, which contains a voltage converter 11, the electrodes of a on the upper part of the housing 2

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attached grid structure 3 supplied with a high DC voltage. A removable wire mesh 5 is connected to the lower part 2 by a snap lock. An insect, for example a house fly, which bridges the electrodes of the grid structure, receives a powerful electric shock from the output capacitor of the voltage converter. The remains are collected in a plastic trough 7, which is accessible after removing the wire netting 5 and the grid structure 3. The trough 7 can be removed from the lower part 2 for washing. The insect will only be stunned by the electric shock, so that it falls into the trough 7 containing water with a slight addition of a detergent, where it then drowns.

One or more attractants for the insects, for example a gas discharge lamp 17, are arranged within the grid structure 3, the gas discharge lamp emitting ultraviolet light which attracts a variety of insects and which also indicates whether the device is working. The middle section of the trough 7 is designed as a foot 13, which is designed as a receptacle 15 at the top / in which a fragrance can be introduced. The fragrance can either be a chemical or a decaying animal or vegetable product. Fragrances usually only work on certain types of insects.

The grid structure 3 has a first and a second helical shape Electrode 19 and 20, which are arranged similarly. Two screw starts are provided. Every turn the electrode is aligned approximately horizontally, which is advantageous as flying insects prefer between horizontal than between vertical electrodes. Due to the helical electrodes

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the grid structure can be made very easily. Leakage currents between the electrodes are minimized in that the electrical connections for the electrodes are provided at points which are angular with respect to the axis of the helical electrode are separated from each other, e.g. by 120 °. The electrodes 19 and 20 are on upright supports 21 and 2 3 attached, made of an electrically insulating material, z.I3. Plastic, and with a part 25 are connected from similar material.

The electrodes 19 and 20 are connected to the output of the voltage converter 11 via connector pins 27 and 28, which through penetrate the trough 7 and the upper wall of the lower part 2 and engage with associated connecting sockets 29 and 30 stand. When the wire mesh 5 is removed from the lower part 2, the lattice structure can therefore together with the wire mesh and the electrodes 19 and 20 are removed so that the grid structure 3 is electrically "dead".

Similar connection plug-in devices are for the gas discharge lamp 17 is provided, which is also attached to part 25

As for the plastic materials used, it appears that some insects have an aversion to certain plastics, such as Perspex (K), which reduces the attractant's effectiveness . Polycarbonates appear to be a suitable material for handling house flies and the like.

Figure 2 shows a circuit diagram for the device similar to Figure 1. A DC-DC converter is used,

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to charge an output capacitor C6. The primary turn a transformer 'Π is with an oscillator circuit connected, the transistors TR1 and TR2 and with the inside 9 of the lower part 2 inserted batteries connected is. The battery voltage is expediently selected in the range between 6 and 9 V. Diodes D1-4 and Capacitors C2-5 connected to the secondary winding of the transformer TI are connected to form a Cockcroft and Walton voltage multiplier, so that a high DC voltage, usually between 2kV and 3kV, is present on the output capacitor C6 is being built. A switch S1 controls the power supply from the batteries to the low-voltage oscillator, while the output capacitor C6 can be short-circuited with a switch S2. These switches are activated automatically the removal of the wire mesh 5 from the lower part 2 is actuated in such a way that the switch S1 opens and interrupts the oscillator and that switch S2 closes and discharges capacitor C6.

The capacitor C6 greatly increases the effectiveness of the device, since it is very small for the current flowing through an insect bridging the electrodes 19 and 20 Forms input resistance, the capacitor being charged relatively slowly by the DC-DC converter can be. Therefore, the DC-DC converter and the batteries do not have to be able to to be able to supply the full short-circuit current that flows at the output when an insect bridges the electrodes 19 and 20.

The primary winding of the transformer T1 is acted upon by an oscillator, which is a programmable switching transistor TR1, which controls a transistor TR2.

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-IJ-

Ι πι Ik; You will drive l capacitor C1 through a resistor R3
on tie LuIfMi, until the voltage at their common connection point exceeds the control voltage of the transistor TR1, which means that the voltage at the connection point of the fixed resistance states II and \ <2 is determined. When the control voltage is too high, a current pulse is applied to the input. I ¹ LMHi; is released ors TR2 as soon as the capacitor CI discharges.

When 'L ¹ RJ turns off, the energy stored in the transformer core creates a back EMF voltage in both the primary and secondary windings. The actual voltage on the primary winding is directly proportional to that on the
The voltage is applied to capacitor C6, and the former voltage is used to set the operating frequency of the oscillator
to control a ZENUR diode D5. As soon as the diode D5 goes into the conductive state, the capacitor C8 is switched to a
higher voltage than that determined by the voltage divider formed by resistors Rl and R2,
charged, whereby the applied to the transistor TR1
Preload is increased. This in turn increases the length of time
that C1 needs to reach the drive voltage of TRI, and thus the operating frequency of the oscillator
reduced. This process continues until the voltage on the capacitor C8 is sufficiently high for the pulses fed to the transistor TR2 so that they occur just enough frequently to make up for the losses in the circuit connected to the secondary winding of the transformer. Due to this operating mode of the oscillator circuit, the life of the batteries can be extended
because, apart from the charging times of the capacitor C6, the current drawn is just sufficient to cover the losses, this current also being used for the operation of the

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-U-

2 "ι Γ) 12 3 7

Lamp 17 is used, which in series niLt the Spunnunqsverv Le I times r 1 i tnj t.

Dliwolil <|! S flat t \ i 1 Is the capacitor Ch directly into it the elec- tr ode Il ιΊ ■ s (1 1 t I e lau t hall S ühe I 'V' ■ l 11 Ι η ι lunqsbU. '■ Ii Sen. ! ¹ I lind ti) connected to graze, isl it also inoql I, in an oil. In heideii from the capacitor C't> to the C, i t1 ere 1 ek L t oden tiing lines a spark chamber ~ Linricht j Si .; I have to be provided, the electrical resistance of which falls from a very high value to a significantly lower value when an insect bridges the electrodes 1 ') and .M). One: such Eunkenkamnier-Eint ichtunq SCl a ['aar held at a distance electrodes in a closed tube ("" have a suitable atmosphere (with. The spark chamber! · It is necessary to avoid the attraction of dust and corpses, since the spunnuruj on the electrodes is quenched in the absence of an insect.

In the execution of the figures i to 7 are those with ilen Share the L'iqur I verq Le ichbare TeiLe with equal He. '. Uqs- ^ calibration by mistake. I) The execution forms go under practically only in constructive as well as operationally technical Regarding what concerns the SchaLturujen, and the following Heschreibunq is essentially aimed at these differences .

In the embodiment (as shown in Figures 5 to 7, a rural housing or lower part 2 made of plastic is provided, which accommodates a voltage converter 11 (Figure 7) which supplies a grid structure attached to the upper part of the housing 2 with a high voltage. A removable Abdeckunq ^r> iius isoLLerendem material, such as plastic zH preferably, the qleiche, which is used in the lower part, is placed on the lower part 2 and held only by a rotatable pawl 5a. DLe cover 5 prevents people from seeing the

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K] (Ή ι oden of the grid structure 3, whereby it makes it cj] i.'ii.'hri.iti cj the i η the cover arrangement penetrated insects to leave them. Any insect that the K] ektroden des Lattice structure 3 bridged, receives a powerful electric shock from the output capacitor of the: q>annumj:; converter. The electrically killed or anesthetized ] n:; ect »τι, such as house flies, or their remains are in an art Kt of f trog 7, which is after removal of the cover ,! LordiHiiKj 5 and the grid structure 3 carried by it to c; iK |] iili, the trough for washing from the lower part 2. In the trough 7 is a "moat" 7a provided so that: ;;; the stunned insects fall into the moat and fall into place.

The covernordnuny 5 has an upper roof part 50 and above andoi1ieijendo louvre-like parts 51, 52, each of which has two perpendicular pairs of adjacent parts, such as 51 ', 51'' and W ₁ 52' ·, each having the shape of one on the K (JpI; ■ (have urgent "V" or "U" . Through the gaps between the roof part 50 and the parts 51 ', 52 "and between the parts ] (M!' J 1 ', 51 ' · and 52 ', 52' ' etc., openings are created through which the insects can hang into the interior of the cover arrangement 5, while at the same time people are prevented from touching the electrodes of the grid structure 3. Inside the grid structure One or more attractants for insects are arranged in 3. In the specific embodiment shown here, a discharge lamp 17, which emits ultraviolet or other light suitable for attracting the insects, is arranged within the grid structure 3. The cap 17 is err by the voltage converter 11 egt and is arranged within a transparent foot standing upright away from the lower part 2. A anlockender perfume, zh a chemical composition or a decaying TIE

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risches or pf] ananz product, can also be used within of the grid structure 3 are provided. Fragrances only work on certain types of insects.

The grid structure 3 has a first electrode 19 and a second electrode 20 that are vertical to each other Spaced supports which form part of the cover assembly 5 are wound. Though the electrodes around the supports are each wound in the manner of a rectangular "screw", vertically adjacent turns of the Electrodes almost horizontal.

Figure 7 shows a circuit diagram of the electrical device of the device according to Figures 3 to 6, which in a space in the lower part 2 is housed, which is accessible after removing a panel in the bottom of the lower part 2. The primary winding of a transformer T1 is connected to an oscillator circuit which is connected as an astable multivibrator Transistors TR1, TR2 and one containing a Darlington pair Has driver TR3 and is connected to the batteries located in the spaces 9 of the lower part 2. the Circuitry connected to the secondary winding of transformer T1 is generally similar to that of the figure 2, if one disregards the fact that the insect-attracting lamp 17 is connected in parallel instead of being connected in series is connected to the voltage multiplier circuit.

During the operation of the circuit of FIG. 7, transistors TRA, TRB operate as a free-running astable multivibrator which switches the TRC on and off at a speed which is close to the resonance frequency of the transformer T1.

The astable multivibrator formed by the transistors TRA and TRB is designed in such a way that it absorbs fluctuations in

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compensates for the battery voltage, especially the gradual decrease in voltage as the batteries discharge. the The switch-on time of the transistor TRA (and thus TRC) is essential shorter than the turn-on time of the transistor TRB. The turn-off time of the transistor TRB is determined by the ZENER diode D2 increases in the same proportion as the battery voltage decreases. The ZENER diode D2 limits the maximum negative The deflection of the right plate of the capacitor CA, which occurs when the transistor TRA turns on. The usefulness is such that the switching frequency is switched on with the TRA and TRC remains roughly constant while the length of their switch-on periods increases as soon as the battery voltage drops decreases. The multivibrator therefore works in such a way that the voltage on the output capacitor is at least one approximately constant value is kept. Due to the fact that the switching frequency remains roughly constant, is the achieved efficiency optimal.

With regard to the switching frequency of TRC, it is desirable to that this is close to the resonance frequency of the transformer T1. However, if the switching frequency is equal to the resonance frequency the mean current through TRC would increase considerably and would be responsible for an increased battery discharge be. Since this cannot be ruled out due to a drift in the multivibrator frequency, it is shown in FIG The exemplary embodiment shows a possibility with which this problem can be circumvented. A resistor RA is connected in series with the primary winding of the transformer T1 and the pair of transistors TRC, while a capacitor CB is connected in parallel with these two components. The resistor RA limits the average current to a value which is acceptable in terms of the load on the batteries, while the capacitor CB the instantaneous, relatively high current which occurs when the transistor pair TRC is turned on.

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eers G i \

Claims (1)

18.120 / 1 40 / egg THORN I) UMKiSTIC APPLICANTS (ELECTRICAL) LIMITED, London / Great Britain Patent (protection) claims: \ 1 J Insect repellant, characterized in that a hollow lattice structure (3) is provided, in which an insect-attractant can be brought in, furthermore at least one eii.tf! Electrode (19) and at least one second electrode (20) and a device (11) for applying a Hochtii .innung to the two electrodes and a capacitor (C6), which is connected in parallel to the two electrodes and stores electrical energy that is transmitted via a the two electrodes (19, 20) bridging insect is broken down. J 2. Apparatus according to claim 1, characterized in that the High voltage device (11) a Cockcroft and Walton voltage multiplier (T2-5, C2-5), which is connected in parallel to the capacitor (C6). 3. Apparatus according to claim 1 oc! I> r 2, characterized in that that the high-voltage device (11) has a battery-operated DC-DC converter a transformer (T1). 809820/1019 4. Apparatus according to claim J, characterized in that a K Lnr ichtuncj (D5) is provided with which the voltage converter (11) is adjustable so that eggs in the company Voltage converter (11) works when the capacitor (Cß) is discharged to quickly charge the capacitor (C6), and then works just enough to compensate for the electrical losses and the capacitor (C6) in that to keep charged state. 5. Apparatus according to claim 4, characterized in that the Adjusting device (D5) responds to the back EMF, the when operating on the primary winding of the transformer (Tl) occurs to adjust the operation of the voltage converter. 6. Apparatus according to claim 3, characterized in that the Voltage converter (M) a circuit (TRA, TRB, TRC) for the delivery of a pulse train for the control of the transformer having, the circuit for increasing the duty cycle (mark-to-space ratio) des [mpulszuges when the battery voltage drops, so that the voltage on the capacitor (C6) on a is kept at least approximately constant value. 7. Apparatus according to claim 6, characterized in that the Circuit is aligned in such a way that the time interval between the pulses is considerably greater .ils the length of the Is keying pulses and that the length of the keying pulses is progressively increased as the battery voltage decreases. 8. Apparatus according to claim 6 or 7, characterized in that that the circuit (TRA, TRB, TRC) has an astable multivibrator with a pair of cross-coupled Transistors (TRA, TRB), each of which has a resistor and a 809820/1019 Capacitor is assigned as a timing element, the voltage swings of the capacitor connected to one transistor , which originate from the other switching transistor (TRA), are limited by a diode (DZ), where the switch-off times of one transistor (TRB) are lengthened, as soon as the battery voltage decreases, in order to change the duty cycle of the pulse train in the manner indicated above. 9. Device according to one of claims 6, 7 or 8, characterized in that a further capacitor (CB) is provided for supplying the transformer (T1) driving current , and a resistor (RA) to limit the speed with which the other capacitor (CB) can be recharged by the battery. 10. Device according to one of the preceding claims, characterized in that a lamp (17) for emitting ultraviolet light is provided within the grid structure (3), which is visible outside the grid structure (3) in order to attract the insects. 11. Apparatus according to claim 10 and one of claims 3 to 9, characterized in that the lamp (17) can be excited by the voltage converter (1t). 12. Apparatus according to claim 11, characterized in that the lamp (17) is a gas discharge lamp which is connected to the circuit connected to the secondary winding of the transformer (T1). 13. Device according to one of the preceding claims, characterized in that the grid structure (3) is mounted on a housing (2) which contains the Hochspannungseinrich device (11) . 809820/1019 14. Apparatus according to claim 13, characterized by a removable Cover (5) which is electrically insulated from the grid structure (3) and is arranged such that it prevents people from touching the grid structure (3) when it is arranged on the housing (2). 15. Apparatus according to claim 14, characterized by a switch (S1) for interrupting the electrical power supply to the hole tensioning device (11) when the cover (5) has been removed from the gel housing (2) and / or the housing (2) is taken apart. 16. Apparatus according to claim 14 or 15, characterized in that that a switch (S2) is provided for discharging the capacitor (C6) when the cover (5) is removed from the housing (2) and / or the housing (2) is disassembled. 17. Device according to one of claims 14, 15 or 16, characterized in that that the grid structure (3) is attached to the cover (5) and electrically connected to the capacitor (C6) With the help of electrical connecting elements (27, 28, 29, 30) which open when the cover (5) from Housing (2) is removed. 18. Device according to one of claims 13 to 17, characterized by a trough (7) for collecting the dead insects or their remains that fall from the grid structure (3), the trough (7) being removable from the housing (2) is. 19. Device according to one of claims 14 to 18, characterized in that that the arrangement is made in such a way that the cover (5) must be removed from the housing (2), before the trough (7) can be removed. 809820/1019 20. Device according to one of the preceding claims, characterized in that a receptacle (15) for receiving a fragrance that attracts the insects is arranged within the grid structure (3). 21. Device according to one of the preceding claims, characterized in that the first and the second electrode (19, 20) are essentially helical. 809820/1019