WO2010041947A2

WO2010041947A2 - Method and device for transferring ultrasonic energy for treating a fluid and/or an object

Info

Publication number: WO2010041947A2
Application number: PCT/NL2009/050615
Authority: WO
Inventors: Mateo Jozef Jacques Mayer; Gerrit Oudakker; Tom Valkenberg; Wilhelmus Blaauw
Original assignee: Water Waves B.V.; Coöperatieve Vereniging EasyMeasure U.A.
Priority date: 2008-10-10
Filing date: 2009-10-12
Publication date: 2010-04-15
Also published as: WO2010041947A3

Abstract

The present invention relates to a method and device for transferring ultrasonic energy to a fluid and/or an object or a plurality of objects. The device comprises: - an ultrasonic transducer; - an amplifier operatively connected to the transducer; and - a function generator operatively connected at least to the amplifier, wherein the transducer is placed in a packed bed of particles.

Description

Method and device for transferring ultrasonic energy for treating a fluid and/or an object

The present invention relates to a method and device for transferring ultrasonic energy to a fluid and/or an object or a plurality of objects. The device and method according to the present invention are highly suitable for instance for disinfecting a fluid and/or decomposing organic components in a fluid and/or crystallization and/or polymerization of a fluid and/or keeping clean an object present in a fluid and/or enhancing mixing in a fluid and/or in a porous object.

It is known in the literature that ultrasonic vibrations can be applied for the treatment of liquid, for instance by cavitation, electroporation, in order to induce crystallization, to clean objects, to decompose organic components, to start and sustain polymerization processes including radical polymerization processes and emulsion polymerization. Most of the above mentioned processes take place with a high energy efficiency if they are carried out on small scale, i.e. on laboratory scale. A problem standing in the way of applying ultrasonic techniques in the process industry is that the energy efficiency of such processes falls dramatically to a few percent or tenths of a percent when the process that works well on laboratory scale, i.e. on millilitre scale to litre scale, is scaled up to cubic metre scale to the order of magnitude of thousand cubic metre scale.

The object of the present invention is to increase the efficiency of the device or method, preferably such that scale-up options are increased.

This object is achieved with the method or device according to the present invention for transferring ultrasonic vibrations to a fluid and/or an object and/or a plurality of objects in a manner such that the device according to the present invention can also be applied on large scale with a high energy efficiency of the process. The device according to the invention comprises the measures of claim 1, and the method according to the invention comprises the steps of claim 26. The technology according to the present invention makes use of a function generator to generate an alternating voltage, an amplifier to amplify the signal and a transducer to convert the electrical signal to ultrasonic vibrations. A sine generator can be used as function generator, although in practice square waves, sawtooth voltages, modulated alternating voltages, including amplitude-modulated signals, frequency-modulated signals and phase-modulated signals, are also found to be readily applicable in combination with the present invention. The frequency of the alternating voltage, the amplitude and modulation form are preferably adjustable. The signal produced by the frequency generator is fed to an amplifier. Commercially available equipment, including audio amplifiers (for frequencies up to about 250 kHz) and transmitting equipment (from frequencies of about 250 kHz to 100 GHz) , is preferably applied as amplifier. A transducer is connected to the output of the amplifier. In order to adapt the impedance of the output of the amplifier to the impedance of the transducer use is preferably made of an audio transformer if an audio amplifier is used, and preferably of a antenna tuner if transmitting equipment is used to control the transducer. It will be apparent to the skilled person that in this way a very inexpensive device can be produced for the purpose of treating a fluid with ultrasonic vibrations.

In a preferred embodiment of the present invention a transducer is placed in a liquid packed with glass beads (marbles) . Although the device according to the invention can also be used without marbles, the glass marbles are found in practice to be able to displace ultrasonic energy through the liquid in a very effective manner. An important reason for this is that the packed bed of marbles does not behave like a rigid object for the ultrasonic vibrations, but that the marbles can move individually in the rhythm of the ultrasonic vibration and can in this way transfer ultrasonic energy. It will be apparent to the skilled person that this method of energy transfer involves unprecedented possibilities, and also makes it possible to displace ultrasonic energy over large distances through a liquid and to scale up processes wherein ultrasonic energy must be transferred to a liquid. It is noted that the marbles can also be manufactured from a material other than glass. It is possible here to envisage metal, ceramic, composite material, polymers. It is further noted that use can also be made of objects in which a hollow space is present with a smaller object therein. If such a marble with a hollow space in which another marble is situated is exposed to ultrasonic vibrations, the small marble enclosed in the cavity of the large marble can then begin to vibrate. It will be apparent to the skilled person that such a marble is highly suitable for use in combination with the present invention. It will also be apparent to the skilled person that instead of applying spherical particles it can be advantageous in determined conditions to apply particles with a different geometry. Non-limitative examples of different geometries are: cubes, cylindrical particles, hollow cylinders including Raschig rings which are also applied in the process industry as column packing, octahedrons. Now that the basis of the present invention has been explained, a number of non-limitative applications of the present invention are mentioned.

In the chemical process industry in general and the field of water process technology in particular there is a growing need for sustainable technology for realizing chemical conversions, purifying process liquids such as water and disinfection of water. In addition there is a need in the food processing industry for non-destructive disinfection techniques with which foods can be disinfected without adding chemicals. With the device and method according to the invention it is possible to kill micro-organisms such as bacteria, viruses, protozoa, algae and parasites in a fluid. In this application the term fluid is understood to mean a liquid, a gas, a vapour, a dispersion of vapour or gas in liquid, a dispersion of liquid droplets in gas or vapour or mixtures hereof. It follows from the foregoing that, while disinfection and decomposition of undesirable components can be realized by treating a fluid with ultrasonic vibrations, desirable compounds present in the fluid could also decompose. For this reason there is a need for ultrasonic techniques with which the frequency and the intensity of ultrasonic vibrations can be adjusted such that only the undesirable components decompose while the desirable components remain intact. In addition to above stated desirable technological specifications, it is important that an ultrasonic treatment apparatus be robust, simple and inexpensive. It is known to the skilled person that the efficiency with which ultrasonic energy is transferred to a fluid and is distributed uniformly over this fluid increases the larger the effective surface area of the applied transducer which is in contact with the fluid becomes. For this reason it is desirable in many cases to equip a treatment apparatus with a plurality of transducers. As a result it is important that the cost price of the control equipment of an ultrasonic transducer, as well as the ultrasonic transducer itself, is low. The present invention relates to a method and device with which it is possible at low investment cost to treat a fluid with ultrasonic energy in a robust, sustainable and reliable manner.

In a first embodiment the present invention is applied for the purpose of keeping clean quartz tubes in UV disinfection systems. To this end the ultrasonic transducer is preferably placed in a liquid with marbles in a manner such that a packed bed of marbles is present below, adjacently of and above the transducer. The quartz tube is subsequently brought into contact with the marbles by means of a mechanical construction. In this way ultrasonic energy can be transferred from the transducer via the liquid and the marbles to the quartz tube without excessive wear of the transducer or quartz tube occurring, such as would be the case with rigid connections. The quartz tube is preferably built into a housing such that it is connected in non-rigid manner to the housing. It is noted that setting the quartz tube into vibration not only results in a higher energy efficiency due to better transfer of UV radiation to the liquid, but also to better mixing in the liquid. A laminar liquid film normally speaking flows along the quartz tube. This means that the mixing of the liquid in the UV reactor is not optimal for disinfection purposes with high energy efficiency. Due to the ultrasonic vibrations the apparent diffusion coefficient in the liquid increases, resulting in a better mixing in the reactor and therefore also a better disinfection. A second synergetic effect of applying ultrasonic vibrations in combination with UV disinfection is that the micro-organisms are weakened by exposure to ultrasonic vibrations, among other ways by electroporation. These micro-organisms hereby become more sensitive to UV radiation, resulting in a more efficient disinfection.

In a second embodiment the technique according to the present invention is applied as crystallization reactor. For this purpose a reactor is packed with marbles and placed in the packed bed are transducers which can be individually activated. It is noted that a reactor preferably comprises a plurality of transducers which optionally operate at different frequencies. With computer-controlled activation of these transducers and by placing ultrasonic microphones in the packed bed which regulate the control of the transducers by means of software, the energy transfer from transducers to the packed bed can be automatically regulated and optimized. It will be apparent to the skilled person that crystallizers can in this way be obtained which can be operated in sluggish flow and with which very uniform crystals can be produced. Such crystals can for instance be applied in the pigment industry. It will also be apparent to the skilled person that applying crystallizers according to the present invention in for instance water softening or brine purification results in a lower consumption of chemicals, less reactor fouling, less maintenance and smaller reactor volumes.

In a third embodiment the technology according to the present invention is applied for the purpose of reducing the energy consumption in separation processes with membranes. It is possible to envisage reverse osmosis membranes, nanofiitration membranes, ultrafiltration membranes, microfiltration membranes. The operation of the present invention is based on suppressing membrane fouling through scaling and biofouling and on increasing the apparent diffusion coefficient in the liquid, this resulting in suppression of concentration polarization. In addition, diffusion in the pores of the membranes can also be accelerated by means of the ultrasonic vibrations. Applying membrane processes in combination with marbles, for instance by packing a membrane housing with marbles and accommodating one or more transducers in the marbles, expressly forms part of the present invention.

In a fourth embodiment the technology according to the present invention is applied as polymerization reactor. Used for this purpose is an arrangement equivalent to the crystallization reactor as described in the second embodiment. In this case however, the liquid consists of a monomer or of an emulsion with monomer and initiator. It will be apparent to the skilled person that the particle size distribution and the molecular weight distribution of the polymer can be adjusted by varying the frequency and amplitude of the ultrasonic vibration to which the liquid is exposed.

In a fifth embodiment the technology according to the present invention is used to disperse ozone in a liquid. To this end ozone or a gas mixture containing ozone is fed to a bed of marbles in which one or more transducers are situated. Owing to the ultrasonic vibrations the ozone is absorbed very efficiently into the liquid.

In a sixth embodiment the technology according to the present invention is applied for the purpose of purifying water in combination with electrolysis and/or UV treatment and/or light treatment and/or treatment with modulated or unmodulated radio waves and/or alternating voltage. The result is that due to synergies water can be disinfected with a smaller amount of energy than if each of the techniques were to be applied separately.

In a sixth embodiment the technology according to the present invention is applied to enlarge the specific area of packing particles so that these particles can be applied for adsorption purposes and/or as catalyst. One or more transducers are placed for this purpose in a packed bed with the particles for functionalizing.

Example 1 A Voltcraft 2 MHz sweep/function generator was set to a frequency of 20 KHz. The output of the function generator was connected to one the inputs of a Raveland XCA 1200 audio amplifier. The output of the audio amplifier was connected to the primary winding of an audio transformer of the Amplimo LTO604 type. The 100 V secondary winding was connected to an ultrasonic transducer of the UltrasonicsWorld type having as specifications: f= 20 kHz +500 Hz; impedance = 28 Ohm/ Input power = 60 Watt; mass = 660 gram; length = 99 mm; construction material = A16061. The transducer was placed in a 1000 ml beaker. A layer of marbles with a diameter of 1 cm was first arranged for this purpose on the bottom. The transducers were subsequently placed on this layer of marbles and a packed bed of marbles was arranged around the transducer, the beaker was then filled with water.

A search was subsequently made with the function generator for the resonance frequency of the transducer by varying the frequency of the ultrasonic vibrations in the vicinity of the initial setting of 20 kHz. As soon as the resonance frequency is reached, the marbles begin to move and slowly rotate. A loud sound is also produced. This demonstrates that the method and device according to the present invention work. It will be apparent to the skilled person that the use of liquid in the packed bed of marbles is desirable in a number of cases, though not essential. It will also be apparent to the skilled person that, by applying for instance a 555 function generator, a simple audio amplifier and a line transformer, the control equipment for the present invention is very inexpensive and can be manufactured from mass products. Such a configuration expressly forms part of the present invention.

According to a first aspect, the technology consists of a power supply. This power supply is preferably a switch-mode power supply and the voltage supplied by this power supply is preferably a poorly smoothed direct voltage in the range between 1 V and 350 V, still more preferably in the range between 5 V and 70 V and most preferably in the range between 10 V and 50 V. According to a second aspect, the present invention consists of a function generator. This function generator preferably produces a non-perfect sine or a square wave having a frequency in the range of 5 kHz to 10 GHz, still more preferably in the range of 10 kHz to 10 MHz and most preferably in the range of 15 kHz to 1 MHz. According to a third aspect, the present invention consists of a single-ended amplifier which is preferably constructed from at least a transistor or vacuum tube and at least a transformer, the single-ended amplifier is still more preferably constructed from a single transistor and a single transformer and this single-ended amplifier is most preferably constructed from a single FET (Field Effect Transistor) and a single transformer. Depending on the frequency applied, an audio transformer or a transformer wound onto a ferrite core can be employed as transformer. According to a fourth aspect, the present invention consists of an ultrasonic transducer supplied with electric energy by connecting this transducer to the output of the single-ended amplifier. According to a fifth aspect, the present invention consists of a device in which the ultrasonic transducers are mounted for the purpose of subsequently bringing the transducers in the desired manner into contact with the fluid. This device can consist of a container which is filled batchwise with or through which the fluid for cleaning flows. The device with transducers can also be designed such that it is placed in a larger container, such as a reactor or a pool, and there ensures that the ultrasonic energy is transferred in the correct manner. In a preferred embodiment the device consists of a tube with Lhe ultrasonic transducers built in.

Now that the features of the present invention have been described, the advantages of this invention compared to existing technology are explained. Commercially available ultrasonic transducers have a resonance frequency. Stated briefly, this means that these transducers must be controlled with an alternating voltage having a frequency the same as this resonance frequency. At frequencies above and below this resonance frequency the efficiency for conversion of electric energy to vibration energy is very low. In order to better explain the advantages of the present invention, without thereby imposing any limitation on the scope of the present invention, the operation of a resonance circuit is now explained. It is known to the skilled person that the behaviour of an ultrasonic transducer can be approximated with a series and/or parallel circuit of at least a coil and a capacitor. We assume for the sake of convenience that we have an ultrasonic transducer whose behaviour can be approximated with a circuit consisting of a coil and a capacitor. If an ultrasonic transducer is controlled by a power source with a frequency which is the same as the resonance frequency, the capacitor is then charged alternatingly, this capacitor subsequently discharges over the coil, wherein the coil creates a magnetic field, and the capacitor is then recharged while reducing the magnetic field. This cycle is then repeated again. Since the power source continuously feeds electric energy into the resonance circuit, the amplitude of the alternating voltage over the capacitor will increase over time. This continues until the electrical losses in the circuit (ohmic resistance of the coil and leakage currents in the capacitor) are equal to the energy supplied by the power source to the circuit. At that moment the system is in equilibrium. As mechanical equivalent it is possible to compare the system to a swing. A swing which is in motion alternatingly converts kinetic energy into potential energy and potential energy into kinetic energy. If the swing is given a push periodically and at the COJ: iecL moment, energy can be added to the system. The amplitude with which the swing moves up and downward then increases. This continues until the amount of energy supplied per unit of time is equal to frictional losses at the suspension of the swing and losses through air resistance. From that moment we have a stationary situation in which the swing moves up and downward with a constant amplitude. If the swing is given a push at the wrong moment, it is very well possible that the swing is slowed down. If the swing is given a push periodically with a frequency lower or higher than the resonance frequency, it will then often be the case that the swing is slowed down.

It will be apparent from the foregoing that if a circuit is fed with an alternating voltage with a frequency other than the resonance frequency, this may result in the circuit not coming into resonance. In the case of the ultrasonic transducer this means that the ultrasonic transducer does not begin to vibrate, and so does not work. It is found in practice in ultrasonic transducers that only very slight deviations of the applied frequency relative to the resonance frequency result in the transducer no longer operating, or operating with a very low efficiency. This is an important reason that commercial equipment for controlling ultrasonic transducers is relatively complex and expensive. As is known per se, and also follows from the reasoning in respect of the swing, it is very well possible to control a circuit with a frequency equal to n times the resonance frequency, wherein n is a whole number greater than or equal to 1. It is thus found in practice that it is often well possible to control a transducer with a frequency equal to two, three or four times the resonance frequency, and even higher frequencies are often found to be feasible. Since a square wave with frequency fb is mathematically equivalent to the sum of all odd harmonics of a sine function with ground frequency fb (so *sin(2*pi*fb)+A*sin(2*pi* (3fb) )+A*sin{2*pi* (5fb)+ ), it is readily possible in practice to control an ultrasonic transducer with a square wave.

Another known phenomenon from high-frequency alternating voltage technology is that a carrier wave with frequency fc which is amplitude-modulated with a frequency fam is mathematically constructed from a sine with frequency fc plus a sine with frequency (fc+fam) plus a sine with frequency (fc-fam). This phenomenon, wherein two sidebands are formed in addition to the carrier wave, can be very readily used in practice to control an ultrasonic transducer. Now suppose that a transducer is controlled with an alternating voltage with a frequency fstuur and suppose that this frequency fstuur differs just so much from the resonance frequency fres of the transducer that this transducer does not enter into vibration. If we then begin amplitude-modulating the alternating voltage which has a frequency fstuur with a frequency { I fres-fstuur I , so the absolute value of fres-fstuur) , a sideband is then created with a frequency exactly equal to the resonance frequency. In that case the ultrasonic transducer will enter into vibration. An ultrasonic transducer can therefore be set into vibration by being controlled at the "wrong frequency" and subsequently making a correction by amplitude-modulating this "wrong frequency" .

The above techniques are found in practice to result in drastic simplification in the control of ultrasonic equipment. On the basis of the explanation with the swing analogy, it can also be concluded that it is possible to control a resonance circuit with a semi-sine: it suffices to stand on one side of the swing and give a push at the right moment. This means that the positive alternation of a sine is sufficient to control a transducer and the energy consumption of such a control is comparable to that of a complete control. This is precisely what we can do with a single-ended circuit in which the gate of a FET is connected to the output of a sine generator. In the negative alternation of the sine with which the FET is controlled the FET does not switch and the amplifier produces no power. In the positive alternation of rhe sine the FET does switch and the amplifier begins to produce power. The output of the amplifier does not however produce a semi-sine. This is caused by the switching characteristic of the FET. A threshold voltage is necessary to allow the FET to conduct and the flow of current through the drain subsequently increases very strongly as the voltage on the gate increases. In analogy with the swing, a short but very intensive push with a high acceleration is thus given each time. Because the amplifier comprises a transformer, this acceleration produces induction voltages. This creates distortions and/or harmonics of the original signal. An ultrasonic transducer is connected to the secondary side of the transformer. This will enter into vibration. Since the transducer makes not a half but a full vibration, it also influences what happens on the primary side of the transformer. The interplay of the above described processes ensures that a very stable control of the transducer occurs, and that the bandwidth of frequencies around the resonance frequency with which the transducer with the function generator can be successfully controlled becomes larger.

This is now elucidated on the basis of a several, non-limitative examples.

Example 2

If a poorly smoothed supply voltage is applied the supply voltage will then display a ripple with a frequency of 50 and/or 100 Hz. This is normally undesirable but, if a single sine generator and amplifier is supplied with energy by this power supply, the output signal of the sine generator will then be an amplitude-modulated sine with a frequency of 50 and/or 100 Hz. This non-ideality in the sine, which is normally speaking an undesirable interference, is in this case very desirable since the transducer, owing to this amplitude modulation, is less sensitive to control with an alternating voltage which differs from the resonance frequency. This means that the design of both the power supply and the sine generator can be considerably simpler compared to the case where a pure sine is applied. An additional advantage is that most commercially available ultrasonic transducers are found in practice to dissipate hardly any energy when a futile attempt is made to control them with a frequency differing from the resonance frequency. A simple sine generator, having coupled thereto a single-ended amplifier in which a transformer is also applied for the purpose of controlling the transducer, is also found to result in feedback. Stated briefly, this means that the transducer, as soon as it enters into vibration, feeds back the resonance frequency to the input of the amplifier and the input signal deforms such that the transducer operates more efficiently. The consequence hereof is that the ultrasonic transducer becomes more insensitive to interference as it is controlled with more power, and as it were stabilizes itself. In the device according to the present invention this phenomenon is usually found to occur "automatically" due to non-idealities (which in this case are desirable}, but can of course also be introduced in simple and inexpensive manner by applying a positive feedback of the transducer to the input of the single-ended amplifier. Control of the transducer via a function generator and amplifier which produce non-ideal sines and/or harmonics and/or square waves and/or noise, and/or wherein the signal to the output of the amplifier is deformed by the ultrasonic transducer being in vibration, expressly forms part of the present invention. Example 3

An adjustable power supply of the "Regulated DC Power Supply GP0250-5" type of the company Takasago LTD, Japan, was connected to a sine generator specially designed for the present invention and shown in figure 1 and set to a voltage of 10 V. The values of the applied components are Cl=C2=C3=1.0nF, C4=C5=lGμF, Rl=IOk, R2=3k, R3=270k, R4=lk, T1=T2=BC547B, OSCl=Kenwood CS-402520 MHz oscilloscope. If Rl is replaced by a potentiometer with a value of 22k, the sine generator can be set to a frequency of between about 12 kHz and 41 kHz.

It is noted that the circuit in figure 1 can be made suitable without problem for frequencies in the range of 100 Hz to 100 kHz and higher by modifying several capacitors and resistors. This has been demonstrated by means of simulations with the software package Edison 4 and by building several of these circuits. The output of the sine generator in figure 1 was connected to an oscilloscope, this being shown in figure 1 as OSCl. Figure 2 shows the shape of the sine produced by the function generator. It can clearly be seen that there is no question of this being a perfect sine shape. Deviations in the sine shape occur particularly at maximum amplitude. These deviations are found in a number of cases to stabilize the operation of the device according to the present invention. It is noted that deviations of other nature, such as noise, use of square waves or amplitude modulation, also improve the stability of the device. If the deviations are too great, the device will on the contrary operate less well. Figure 3 shows a single-ended amplifier designed for the present invention. As shown in the figure, the amplifier consists in this case of two components: Tl=FET IRF840 type; TRl= audio transformer LT0604 type from the company Amplimo. Point A of the circuit in figure 3 is connected to the output of the sine generator i.e. to capacitor C5, and point B to the earth, i.e. the minus of power supply Vl . Point C is connected to the plus of power supply Vl in figure 1. Connected to the secondary winding of transformer TRl is an ultrasonic transducer UT with a power of 50 Watt and a resonance frequency of 20.2 kHz. The ultrasonic transducer is placed in a beaker with a volume of 1000 ml which contains marbles with a diameter of 15 mm and is filled 50- with water. The power supply Vl is set to 6 V and switched on. The resonance frequency is subsequently located and, as soon as the ultrasonic transducer is operating, an audible sound is created which is produced by the marbles and minuscule air and/or vapour bubbles are also discernible in the liquid which are held in their place by the uilidsoiiic vibrations. The supply voltage is then increased to 15 V. At a supply voltage of 15 V the power take-up by the transducer is about 30 Watt. At a supply voltage of 20 V the power take-up by the transducer amounts to about 60 Watt. It is noted that during the experiments hearing protection was worn for safety reasons.

Figure 4 shows the shape of the signal as measured with an oscilloscope during operation of the transducer at the location where audio transformer TRl is connected to the FET. Figure 4 clearly shows that this is not a sine but that the amplifier produces a strongly misshapen semi-sine. This is in line with the expectation since FET Tl switches during the positive alternation of the sine supplied by the function generator in figure 1 and closes during the negative alternation of the sine supplied by the function generator in figure 1. Given the switching characteristic of Tl, the signal supplied by Tl is a strongly deformed sine because the current increases very strongly from a determined voltage on the gate as a function of this voltage on the gate. In short, the FET behaves more like a switch than an amplifier. Figure 4 shows that due to the vibration of the transducer and operation of transformer TRl harmonics and/or distortions of the original signal are measurable on the primary side of the transformer. These harmonics and/or distortions are found to have a strongly stabilizing effect on the control of the transducer. On the secondary side of transformer TRl a series circuit of two resistors of respectively 10k and 100k is placed parallel to the transducer, so creating a voltage divider. An oscilloscope is then connected to the resistor of 10k. Figure 5 shows the signal measured on the secondary side of the transformer TRl with an oscilloscope. This signal shows clearly that the transducer makes a full vibration and that this is also manifest in the signal over the transducer. The presence of transformer TRl is found to be an important component in all circuits of the present invention which, through induction, creates an extra degree of freedom for the transducer for the purpose of distorting the presented signal by means of induction such that the transducer functions optimally. In order to further illustrate this, the supply voltage is further increased at the setting in figure 1. This results in the transducer supplying a greater power of ultrasonic vibrations, which is clearly discernible in the beaker with the marbles: the marbles now rotate and air bubbles move through the liquid. Figure 6 shows the signal over the transducer, which is measured with an oscilloscope, under these conditions. Clearly discernible is the different shape of the signal relative to the signal in figure 5, while the transducer operates very well under both conditions. It is mentioned for the sake of completeness that the signals in figure 2, 4, 5, 6 are measured with an oscilloscope and that a movement upward in vertical direction represents an increase in the voltage difference between the points to which the oscilloscope is connected, and that displacement from left to right represents an increase over time. It will be apparent to the skilled person that the circuits in figures 1 and 3 can be further optimized. The experiments with the circuits in figures 1 and 3 clearly demonstrate however that they form a very efficient, stable and inexpensive control for an ultrasonic transducer. It will be apparent to the skilled person that the electronic circuit according to the present invention is also suitable for applications other than the treatment of a fluid. A number of non-limitative examples is: cleaning of objects including jewels, bringing into solution solid substances including salts, precipitating of solids including salts, the production of membranes, the repair of hairline cracks in metal connections, the production of nanoparticles by means of emulsion polymerization, the sputtering of metal on surfaces, repelling insects with ultrasonic sound, influencing the metabolism of plants in general and trees and algae in particular. These applications expressly form part of the present invention. It is finally noted that the control according to the present invention is highly suitable for continuous adjustment of the power of the transducer by means of applying an adjustable power supply and that at high frequencies, i.e. frequencies above 200 kHz, another type of oscillator, such as for instance a Colpitts oscillator, can very readily be used in addition to a sine generator according to the present invention.

According to a first aspect, the technology consists of a function generator which generates a sine and/or a square wave and/or a sawtooth and/or a pulse with a very precisely adjustable frequency. According to a second aspect, the technology consists of a power supply which supplies a preferably smoothed direct voltage and which is connected by means of transistors to the primary coil(s) of a transformer in a manner such that a current flows through the transformer in the rhythm of the signal with which the transistors are controlled by the function generator. The secondary coil of the transformer has a number of windings relative to the primary coil{s) such that the impedance of the transformer on the secondary side is adapted to the impedance of a transducer.

According to a third aspect, the technology according to the present invention consists of a transducer connected to the secondary side of the transformer. This transducer is preferably an ultrasonic transducer. According to a fourth aspect, the present invention consists of a housing on which contacts are arranged on the outside. These contacts make it possible to couple a plurality of housings to each other by means of a snap system and in this way provide all housings with current, since the ultrasonic installation in each housing is connected in parallel to the other housings by means of the snap system. According to a fifth aspect, the present invention is characterized by a central power supply which supplies a safe low voltage, preferably 24 V, to which all housings are connected via the contacts of the snap system.

Now that the principle of the technology according to the present invention is known, there follows a non-limitative list of a number of embodiments.

In a first embodiment use is made of a switch-mode power supply which supplies a direct voltage or an alternating voltage in the range of 1 V to 100 V. Use is preferably made of a direct voltage of 24 V which is supplied by a preferably centrally arranged switch-mode power supply. This power supply is connected to the contacts of ultrasonic installation 1. Ultrasonic installation 1 further comprises a second set of contacts which are likewise electrically interconnected to the direct voltage of 24 V. An ultrasonic installation 2 can subsequently be coupled to ultrasonic installation 1 by means of a snap system, with the result that the contacts of ultrasonic installation 1 are in electrical connection with those of ultrasonic installation 2. The result is that ultrasonic installation 2 is in this manner electrically interconnected to ultrasonic installation 1, and so also to the power supply of 24 V. By making a number of identical ultrasonic installations, a system is in this way obtained which makes the coupling of ultrasonic installations for the purpose of increasing capacity very simple. Since the voltage transmitted from ultrasonic installation to ultrasonic installation is a low voltage (in this case 24 Volt) , the system is inherently safe and use can be made, if desired, of a simple snap system with exposed contacts.

Present in each ultrasonic installation is an electrical circuit which converts the direct voltage to a voltage adapted to the electrical properties of the ultrasonic transducer. The electrical circuit preferably consists of a microprocessor which supplies a pulsed direct voltage on at least one, but preferably on two, channels and in counter-phase. If channel 1 is switched on channel 2 is switched off, and vice versa. The channels are switched on and off with the clock frequency of the microprocessor as time base. In this manner a very stable frequency of the function generator is obtained which hardly drifts. The signal supplied by the microprocessor is then used tυ switch one or more transistors which subsequently cause ct current to run through the primary coil of the transformer with the frequency at which the microprocessor is programmed. A voltage is hereby created in the secondary coil of the transformer and a current runs through the transducer connected to the secondary side of the transformer.

In a second embodiment one of the above embodiments is applied, wherein in each housing provided with electric energy by the central power supply the current supplied to the ultrasonic installation in the relevant housing is measured. This measurement takes place via an AD converter connected to the microprocessor serving as function generator for the purpose of switching the ultrasonic installation in the relevant housing. The AD converter is preferably integrated in the microprocessor. If the current through the electronic circuit in the relevant housing becomes too great or too small, the microprocessor can optionally be switched off and only switched on again if the power supply is interrupted. It will be apparent to the skilled person that in this way a software fuse has been realized wherein use is made of the microprocessor already present in each housing for the purpose of controlling the ultrasonic installation. It will further be apparent to the skilled person that the sensor for measuring the current supplied to the electronic circuit in each housing can consist of a resistor in series with the electronic circuit for the ultrasonic installation in each housing. Use can however also be made of a light sensor, a sensor for magnetic fields, a sensor for electric fields, a sensor for electromagnetic fields, a sensor for ultrasonic vibrations or an acoustic sensor. If desired, the signal supplied by one or more of these sensors can be used to automatically optimize the operation of each ultrasonic transducer via a feedback. This can take place by means of software in the microprocessor which automatically sets the function generator at the optimal frequency if it drifts due to for instance wear of the electrodes.

In a third embodiment the central power supply applied in embodiments 1 and 2 consists of a switch-mode power supply constructed in a manner similar to the design of each individual power supply for the ultrasonic installation in each housing. Such a power supply therefore preferably consists of a microprocessor which is programmed as function generator, switching transistors and a transformer. In this case the alternating voltage of the mains electricity is preferably rectified. This direct voltage is subsequently connected to at least one switching transistor, preferably a FET comparable to the IRF840 type. The switching transistor (s) are controlled by the microprocessor which is used as function generator and are connected to at least a primary coil of an isolating transformer. A current will as a result begin to flow through the primary coil in the rhythm of the signal generated by the microprocessor. The result hereof is that an alternating voltage is created over the secondary coil of the transformer. By now adjusting the ratio of the number of windings of the primary and the secondary coil to each other according to known principles, with subsequent rectifying and optional smoothing, it is possible to ensure that the central power supply supplies a direct voltage of 24 V. The central power supply can also be protected against overload by making use of a circuit as in above described embodiments. In a fourth embodiment, in order to prevent the equipment according to the present invention causing interference in other devices, one of the embodiments 1 t/m 3 is combined with common filter techniques to prevent the generated alternating voltage causing interference in other equipment through displacement via the mains electricity or because the circuit according to the present invention acts as a transmitter. It is noted here that the design of the required filter is simple and efficient since the alternating voltage is generated with a microprocessor as function generator, and the frequency of alternating voltage generated by the function generator consequently does not vary, or hardly so. It is hereby possible to utilize a highly selective filter of small bandwidth in order to prevent interference in other systems by the switch-mode power supply.

Example 4

An accumulator of Vl which supplies a voltage of 24 V was connected to the circuit in figure 1. The function of the respective components in figure 1 is now explained, as well as the operation of the circuit. Capacitor C3 with a capacitance of 1000 μF/lOOV is a smoothing capacitor which receives the alternating load from accumulator Vl. Transistors T3 and T4 are of the BC547B type, are fed by a function generator via points A and B and serve to amplify the signal supplied by the function generator. Resistors Rl and R2, both with a value of 100 Ohm, limit the current which runs through collector and emitter of transistors T3 and T4. Transistors T3 and T4 are of the IRF540 type. The function generator is connected to points A and B. The function generator supplies a signal alternatingly to point A and point B. In other words: Point A is first provided by the function generator with a voltage which is equal to 5 V. This voltage is subsequently held at 5 V for a time tl. The function generator then makes the voltage on point A equal to 0 V. As soon as the voltage on point A amounts to 0 V, the function generator switches the voltage on point B to 5 V. This voltage is likewise held at 5 V for tl seconds while the voltage on point A still amounts to 0 V. After the voltage on point B has been held at 5 V for tl seconds, it is again brought to 0 V and the voltage on point A is again brought to 5 V. This cycle is repeated endlessly. This results in transistors T3 and T4 being switched alternately on and off. This then has the result that, via C2 with a capacitance of 4.7 μF and R6 with a value of 300 Ohm, tπe FET Tl and, via Cl with a capacitance of 4.7 μF and R5 with a value of 300 Ohm, the FET T2 are switched alternately. The consequence hereof is that the current through the primary coil of transformer TRl runs via the centre tip of TRl alternately through FET Tl and FET 12. This results in transformer TRl being provided in very efficient manner with an alternating voltage, which in this case is transformed up by TRl to a desired value i.e. to the value required to allow the load Ll, an ultrasonic installation, to operate at the desired power.

Now that the operation of the circuit in figure 1 is known, there follows a brief explanation of how the desired signal on points A and B can be realized in efficient manner with great accuracy and stability. This is done with a microprocessor. Use is made in this case of the PIC16F84A microprocessor, although a range of microprocessors can be used for the application according to the present invention. This microprocessor was powered via accumulator Vl. To this end the voltage of 24 V supplied by Vl was reduced by using a voltage regulator of the LM317 type. This voltage regulator was set in accordance with the diagram in the accompanying datasheet to a constant voltage of 5 V. This output voltage of the LM317 was fed to the microprocessor. The clock speed of the microprocessor was further set by making use of an external 20 MHz crystal, this as indicated in the datasheet of the PIC16F84A. The microprocessor was programmed to alternately make output RBl and RB2 "high" (bring it to 5 V) . Output RBl was connected to point A in figure 1 and output RB2 to point B. By applying the above described circuit the desired frequency at which the switch-mode power supply operates can be set by means of software. The circuit can hereby be employed in flexible manner. The PIC16F84A microprocessor was programmed at a frequency of 40 kHz. Used as transformer TRl was a ring core transformer of the Amplimo 3N1262 type. This transformer has two windings for 25 V which can be connected in series and which are separated galvanically from a winding for 240 V. The windings for 25 V were connected m series and are referred to in this application as the primary windings. The secondary winding is the winding of 220 V. Connected to the secondary winding was an ultrasonic transducer with a power of 20 Watt and a resonance frequency of 40 kHz. The transducer was placed in a beaker with water. The circuit was switched on and it was found that the ultrasonic transducer operated well: a hissing sound could be heard and air bubbles were found to be created in the liquid which were either stationary or displaced through the liquid at great speed. The circuit was further found to be very efficient. FETs Tl and T2 did not become warm at a taken-up power of 20 Watts.

It will be apparent to the skilled person that this circuit is capable of considerable further optimization. The example does however clearly show that the technology according to the present invention works, and that ultrasonic generators can be provided with energy with a very high efficiency, wherein the energy source is a low voltage which in this case amounts to 24 V. It is noted that the connection for ingenious coupling of ultrasonic installations with a snap system as described in this application is only an example. The system as described in this application, as well as the electronic control, is generally applicable for ultrasonic installation systems. Such ultrasonic installation systems expressly form part of the present invention.

There is often a need in electrical engineering to simultaneously have available a high voltage and a stabilized low voltage. This need arises from the fact that a large number of ICs, including microcontrollers but not limited thereto, have to be powered with a low voltage of 5 V. It is however undesirable to realize the 5 V supply by making use of a 50 Hz transformer, as this has a relatively high cost price. Applying two resistors as voltage bridge so as to obtain a direct voltage of 5 V in this way is not acceptable because of the large amount of electric energy which is converted to heat in the largest resistor of the voltage divider.

The present invention relates to a new type of electronic circuit with which it is possible to obtain in efficient manner a high voltage, a first low voltage and a second low voltage. With the technology according to the present invention it is considerably cheaper to control ICs, including microcontrollers, via the mains electricity than is possible according to the prior art. The embodiment provides means for rectifying the alternating voltage from the mains electricity, means for converting at least a part of the alternating voltage from the mains electricity to a first direct voltage which is lower than 50 V and preferably higher than 5 V, and means for further reducing the first direct voltage to a second stabilized voltage which is lower than preferably 7 V, so that the second stabilized direct voltage can be applied as power supply for one or more microprocessors and/or microcontrollers and/or other ICs which must be powered with a stabilized low voltage.

An embodiment according to the invention is elucidated on the basis of figures 7 and 8 forming part of this application.

A first embodiment of the technology according to the present invention is shown in figure 7. The mains voltage is single-sided rectified using diode O4. The rectified voltage is smoothed with capacitor C4. The plus of a rectified and smoothed high voltage is hereby created on point B. Via the network Cl, Dl, C2, D2, D3, C3, D5 a stabilized first direct voltage is generated. Diode D5 is a zener diode which is preferably set to a voltage of 24 V. A voltage regulator, such as a regulator/stabilizer of the LM317 type is preferably connected to point A in figure 7. Stated briefly, we then obtain a high voltage on point B, a first low voltage of for instance 24 V on point A and a second low voltage of for instance 5 V over the additional voltage regulator/stabilizer. It will be apparent to the skilled person that a power supply according to figure 7 and the additional voltage regulator/stabilizer are highly suitable for applications wherein a high voltage is required and wherein one or more ICs operating at 5 V must be controlled and wherein a second higher direct voltage is also required, for instance for the control of FETs via a microprocessor operating on the direct voltage of 5 V. Such a control can, as non-limitative example, be as follows: a PIC of the 16F84A type connected to the o V supply controls the base of a tiansistoi BC547B via an output. This transistor is connected via the emitter to the zero and via a collector resistor to the 24 V supply. The result is that, when the output of the PIC is set to 5 V, the transistor is controlled. Via a coupling capacitor on the collector resistor and a voltage divider a FET can now be controlled via the mains electricity without the use of a transformer being necessary. It is further noted that the circuit is designed such that capacitors Cl and C2 may be monopolar. This means that electrolytic capacitors may be used for Cl and C2, this resulting in an additional cost-saving. The circuit in figure 7 is particularly useful if the load of the high voltage does not demand very high powers i.e., powers lower than about 100 watts. At higher powers the circuit in figure 8 is recommended. The circuit in figure 8 greatly resembles the circuit in figure 7. In this case however, use is made of a diode bridge. Rectification of the voltage is hereby not single-sided but double-sided. This has the advantage that capacitor C3 can be relatively small, while the voltage through C3 is then stabilized to some extent. A direct voltage is obtained on point C. It is noted that a direct voltage is only applied to point C if the circuit between A and B is loaded. This is because the circuit makes use of the fact that, owing to an ingenious choice of capacitor C3, which must have a sufficiently low value, the voltage between points A and B is not completely smoothed. For many applications a high voltage with limited smoothing is not a problem, and in a number of cases such a limited high voltage is even desirable. The great value of the technology of the present invention lies on the one hand in the general applicability of the circuits in figures 7 and 8 and on the other in the fact that the circuits in figures 7 and 8 operate very well and, in a number of cases, even better than conventional, very well smoothed power supplies.

Now that the technology according to the present invention has been described at length, a number of further preferred embodiments thereof follow.

In a first pxefeiied embodiment the technology according to the present invention is applied for controlling ultrasonic transducers. When these ultrasonic transducers are controlled by means of a microprocessor, for instance of the 16F84A type, followed by a pre-amplifier, a power amplifier and a push-pull transformer wherein the transducer is connected to the secondary side of the transformer, an extremely efficient system is then obtained. The high voltage which is supplied by the circuit in figure 7 or 8 and which powers the FETs of the power amplifier is not perfectly rectified. This results in an amplitude-modulated high voltage. This is advantageous as it can be understood mathematically as the sum of three sinusoids having as central frequency the resonance frequency of the transducer and, as sidebands, frequencies which are higher and lower at a distance from the resonance frequency which is equal to the frequency of the amplitude modulation. A small drift of the resonance frequency over time due to wear of the transducer does not therefore cause problems. In a second preferred embodiment the technology according to the present invention is used to control gas discharge lamps. In the control of gas discharge lamps a fluctuation of the high voltage is not relevant, whereby the power supply according to the present invention can be applied. An unexpected advantage of the power supply is that at start-up of the gas discharge lamps an extra-high voltage pulse is created by the amplitude modulation of the high voltage. The lamp hereby ignites better and has a longer lifespan. It will be apparent to the skilled person that the push-pull transformer can be construed as isolating transformer, so that for instance an ultrasonic transducer controlled according to the technology of the present invention is safe to touch. In addition, it will be apparent to the skilled person that the technology according to the present invention can be employed very widely and the preferred embodiments should therefore be seen as non-limitative examples of applications. Finally, it is noted that a plurality of applications can also be connected to one and the same secondary coil of an end transformer. If one of those applications is an ultrasonic transducer, a desirable stabilization of the operation of this transducer can take place due to fluctuations in amplitude and phase of the power supply to the transducer.

The present invention also relates to a method and device for simultaneously controlling disinfecting equipment, characterized by a power source which can be connected to the mains electricity and which supplies a rectified high voltage of for instance 300 V and/or a rectified low voltage of for instance 24 V, means for generating a pulsed alternating voltage or a pulsed direct voltage, at least an amplifier for amplifying the alternating voltage and/or the pulsed direct voltage, more than one transformer with at least a primary and a secondary winding and more than one load circuit. Non-limitative examples of disinfecting equipment which can be controlled simultaneously with the technology of the present invention are gas discharge lamps, including UV lamps, ultrasonic transducers, ozone generators, devices for electrolysis, devices for killing micro-organisms with alternating voltage and electromagnetic transmitters .

Disinfection in general and disinfection of drinking water in particular are of great social importance for safeguarding public health. In addition to safe food and a safe environment, i.e. free of organisms detrimental to health, it is of great social importance that disinfection be realized in a sustainable manner. The inventors of the present invention have established that simultaneous application of different disinfecting techniques works better per Watt of consumed electric power than each of these techniques separately. Disinfecting techniques are understood in the present invention to mean: disinfection by ultrasonic vibrations, UV radiation, electromagnetic radiation, ozone, electrolysis. For the above stated reason there is a commercial demand for a control which makes it possible at low investment cost to realize control systems with which it is possible, with low eneiyy consuxaption, Lu apply a plurality of disinfecting techniques simultaneously. This is possible with the technology according to the present invention. In order to explain the technology according to the present invention as clearly as possible, a method and device are first described for providing gas discharge lamps (UV-C disinfection lamps) with electric energy. Subsequently explained is how, from the building block for controlling a gas discharge lamp, a plurality of controls, i.e. controls for other disinfecting devices, can be realized in cost-efficient way.

According to a first aspect, the technology according to the present invention consists of a power supply. This power supply preferably obtains its electric energy from the mains electricity supply or from a battery or from a solar cell or from a turbine, including a wind turbine, or from a microbial fuel cell. According to a second aspect, the present invention consists of a microprocessor and/or microcontroller and/or PC, referred to below simply as microprocessor, which supplies a pulsed direct voltage, such as for instance a square-wave voltage, alternately on at least two outputs. The frequency and optionally the amplitude of the pulsed direct voltage can be adjusted by means of software and the clock speed of the microprocessor is preferably set by means of an external crystal. According to a third aspect, the present invention consists of a pre-amplifier which amplifies each of the (square-wave) voltages supplied by the microprocessor. Such a pre-amplifier preferably consists of a NPN transistor, such as a transistor of the BC547B type, which is connected with the base to the output of the microprocessor, the emitter to the zero and the collector of which is connected via a collector resistor to the plus. According to a fourth aspect, the present invention consists of a power amplifier which is powered by the pre-amplifier . The power amplifier preferably consists of two FETs. The gate of each FET is connected to a channel of the pre-amplifier . For the coupling of the gate of the FETs to the pre-amplifier use is optionally made of two resistors as voltage divider and/or a coupling capacitor and/or a zener diode. The end result is that both FETs of the power amplifier are alternatingly switched on and off by the microprocessor. Use is preferably made of N FETs and a non-limitative example of a suitable FETs are FETs of the IRF640 type. The drain of both FETs is connected to the primary winding of a transformer eguipped with a centre tap. The centre tap is connected to the plus of the power source. By now alternatingly switching the two FETs an alternating voltage is generated on the secondary winding of the transformer. Stated briefly, the power amplifier operates according to the push-pull principle. According to a fifth aspect, the technology according to the present invention consists of an electronic circuit which is connected to the secondary winding of the transformer and which consists of at least a gas discharge lamp, optionally having connected thereto a coil and/or a capacitor and/or a network of coils and capacitors. An embodiment which operates well in combination with the present invention is a capacitor in series with the gas discharge lamp in series with a first coil. A second coil is subsequently placed parallel to the gas discharge lamp. The thus obtained circuit can be dimensioned such that the load of the transformer is substantially an ohmic load, i.e. the phase difference between current and voltage is substantially equal to zero. In this specific circuit the current which begins to flow through the gas discharge lamp can be adjusted by choosing the value of the capacitor. The inductivity of the first coil and the second coil is then chosen such that the network connected to the secondary winding of the transformer approximates as closely as possible an ohmic load. According to a sixth aspect, the present invention consists of a program in the microprocessor which, initially for a short period referred to below as the ignition period, places an alternating square-wave voltage with a low frequency on the outputs of the microprocessor and then an alternating square-wave voltage with a high frequency. The result is that the secondary circuit is loaded uuxiny the ignition period with an alternating voltage with a low frequency, and then with an alternating voltage with a high frequency. It will be apparent to the skilled person that with this method a very high peak voltage is created over the gas discharge lamp during the ignition period. This peak voltage is much higher than the voltage which is applied over the gas discharge lamp at a higher frequency of the alternating square-wave voltage. A very important advantage of the technology according to the present invention over the prior art is that, making use of the elucidated electronic circuit, the gas discharge in the lamp, i.e. the ignition of the lamp, can be realized by means of software. After ignition the frequency can then be set to the desired value by means of software, wherein the level of the frequency set determines the magnitude of the current limited by the capacitor. A separate ignition circuit is thus not necessary. Preheating of the gas discharge lamp by means of a spiral filament is not necessary either. The lamp can further be dimmed by means of software by varying the frequency of the alternating voltage generated via the microprocessor.

Now that the technology according to the present invention has been explained at length, a number of preferred embodiments of the present invention are set forth.

In a first preferred embodiment the power supply is a low-voltage power supply or a battery. This means that the FETs can be connected to the power side with 24 V. By transforming up the voltage in the transformer with centre tip an alternating voltage is created which is sufficiently high to allow the technology according to the present invention to operate. A transformation factor of between 0.1 and 30 (total number of windings of the secondary coil divided by the total number of windings of the primary coil of which the centre tip forms part) , more preferably between 1 and 10 and most preferably between 2 and 6 is a good value in practice for allowing the technology according to the present invention to operate well at a 24 V direct voltage. This embodiment is highly suitable for the purpose, making use of a direct voltage such as a battery, of creating very high-quality TL-light, i.e. light without annoying flickering, which is generated with a high energy-efficiency. This embodiment is further highly suitable for disinfection installations with UV lamps which are powered from low voltage.

In a second embodiment the power supply consists of a rectified and smoothed mains voltage. This means that the FETs on the power side are connected to high voltage. The low voltage which is necessary to allow operation of the microprocessor and the pre-amplifier is obtained by bringing the mains voltage via a diode - resistor - capacitor combination to 24 V and subsequently using this 24 V voltage to power the collector of the pre-amplifier . The microprocessor obtains its 5 V voltage by bringing down and stabilising the 24 V voltage with for instance a LM317 IC. It will be apparent to the skilled person that it is possible in this way to power the gas discharge lamp directly from the mains without a 50 Hz transformer being necessary. This method of operation in combination with the technology according to the present invention results in a significant cost advantage.

The second embodiment is particularly suitable for switching TL-lighting in offices, switching UV lamps in sunbeds and disinfection systems with UV-C lamps. In a third embodiment a gas discharge lamp is connected directly to the secondary side of the transformer and a low resistance of preferably 1 ohm is incorporated in the circuit. The current through the gas discharge lamp can be determined by measuring the voltage over the resistor with an analog to digital converter with the microprocessor. This current can then be regulated by setting, by means of software, the duty cycle and/or frequency of the alternating voltage created on the secondary coil. It will be apparent to the skilled person that this technique of setting current can also be applied in combination with all other embodiments, and that it is also possible in this manner to correct for ageing of the lamp.

In a fourth embodiment the gas discharge lamp is provided with a sensor. This sensor can be a simple photodiode or light-sensitive resistor. Automatic correction for ageing of the lamp is then made by means of software via the microprocessor. Stated briefly, this means increasing the frequency of the alternating voltage by means of software as soon as the light output of the lamp decreases.

Example 5

A PIC processor of the 16F84A type is powered via a 24 V laboratory power supply. Used for this purpose is a voltage-stabilizing element which converts the voltage of 24 V to a voltage of 5 V. This is realized by making use of a voltage regulator of the LM317 type. It is noted that a zener diode can also be employed as cheaper alternative for this application. The software of the PIC processor is set such that with a frequency of about 25 kHz a square-wave voltage is applied alternatingly to output 1 and output 2 for 1 second. The pre-amplifier consists of two transistors of the BC547B type which are each powered at the base by the PIC processor. The collector of each transistor is connected via a collector resistor of 470 ohm to the plus and the emitter of each transistor is connected to the minus. On the collector the pulsed voltage is taken off with a coupling capacitor of 1 micro Farad. The coupling capacitor is then connected to a voltage divider which consists of a series circuit of a resistor of 470 Ohm and 1 kilo Ohm and which is connected via the resistor of 1 kilo Ohm to the zero. The voltage over each resistor of 1 kilo Ohm is applied over the gate of a FET of the IRF640 type. The drain of each of these FETs is connected to an outer end of the primary coil. The centre tip of the primary coil is connected to the plus of the power supply. The source of both FETs is connected to the zero. The transformer consists of a primary coil with centre tip and a secondary coil, wherein the ratio of the number of primary windings : number of secondary windings equals 1:5. The transformer is made suitable for frequencies between about 15 kHz and 80 kHz, with optimal operation at a frequency around 40 kHz. Connected to the secondary side of the transformer is a capacitor with a capacity of 3900 pico Farad connected in series to an 18 Watt TL tube and a coil with an inductivity of 1 millihenry. Connected parallel to the TL tube is a coil with an inductivity of 6.8 millihenry. The PIC processor is programmed with software which first produces an alternating voltage on the secondary side of the transformer with a frequency of 25 kHz. This frequency is applied to the secondary side for 1 second. The software in the PIC processor subsequently increases the frequency from 25 kHz to 40 kHz. Switching on the power supply provides an ignition of the lamp within 1 second, after which the lamp lights up with a power of 18 Watt and a very pleasant bright light without flickering effects. This example demonstrates unambiguously that the technology according to the present invention operates well, and can in principle be applied to control any gas discharge lamp. It will be apparent to the skilled person that, instead of power transfer according to the push-pull principle, power transfer can also be applied according to the single-ended principle. This is economically advantageous particularly at low powers, since in this manner it is possible to dispense with the use of a power transistor or FET.

Now that a number of features of the technology according to the present invention is known, the technology according to the present invention is described in detail. As is known from the description of the gas discharge lamp, the technology according to the present invention comprises a microprocessor. This is preferably a PIC microcontroller, for instance of the 16F84A type. This microcontroller has a large number of I/O ports. In the application for the gas discharge lamp, for most applications, but not all, only two output ports are used for the purpose of controlling the push-pull transformer. The other ports are still available. Controls according to for instance the push-pull principle can also be connected to these other ports. Of the microprocessor already in use to control a UV-C lamp it is thus possible for instance to also use two additional ports with which a second pre-amplifier and a second power amplifier are controlled, which in turn control a second push-pull transformer with centre tip, so creating a second control. Since the microprocessor can be equipped with an external crystal, the frequency at which both the first and the second control operate can be set with very great accuracy and with very great reliability. In the case the second control is an ultrasonic transducer, this is of essential importance because the transducer has a resonance frequency at which the operation is optimal and the load displays ohmic instead of inductive or capacitive behaviour. It will be apparent to the skilled person that in this manner it is technically possible with a single microcontroller to regulate both the control of a UV-C disinfection lamp and the control of an ultrasonic transducer by means of software and independently of each other. This is an important feature of the present invention. Now that the principle of the present invention has been explained, there follow a number of preferred embodiments.

In a first preferred embodiment a number of ports of a single microprocessor are used to realize more than one control of gas discharge lamps. An inexpensive control of a lighting system is realized m this manner since only one central microprocessor is applied as function generator and further required per lamp are only a pre-amplifier, end amplifier and transformer. It is noted that for lighting in general, for sunbeds, for disinfection units with a plurality of UV lamps this system is a sustainable and economic alternative to the systems which operate according to the prior art.

In a second embodiment a (system of) disinfection lamp(s) and a (system of) ultrasonic transducer (s) are controlled with a single microprocessor.

In a third embodiment a (system of) disinfection larap(s) and a {system of) electrolysis units are controlled with a single microprocessor.

In a fourth embodiment a system consisting of at least an ultrasonic transducer and an ozone generator is controlled with a single microprocessor.

In a fifth embodiment a system consisting of at least an ultrasonic transducer and/or a UV-C disinfection lamp and/or an electrolysis system and/or an electromagnetic transmitter and/or an alternating voltage generator is controlled with a single microprocessor.

In the list of embodiments controlling is also understood to mean: providing with electric energy by means of a pre-amplifier, power amplifier, a transformer wherein the disinfecting device is operatively connected to the secondary- coil of the transformer.

In addition, controlling is understood in the embodiments to mean: controlling the process to which the disinfecting device is connected or of which the disinfecting device forms part. Using the microprocessor, in addition to realizing the energy supply in the correct form (amplitude, frequency of an alternating voltage which can be set per control by means of software, direct voltage), valves, pumps, closing valves can also be controlled, measuring equipment can be read and, on the basis of signals collected by sensors, an alarm can be given or a follow-up action started. The software in the microprocessor with which control according to the definition in this document can be realized, i.e. a program being a method for controlling a plurality of energy supplies with a processor, expressly forms part of the present invention. The present invention is by no means limited to the above described preferred embodiments thereof. The rights sought are defined by the following claims, within the scope of which many modifications can be envisaged.

Claims

1. Device for transferring ultrasonic energy for treating a fluid and/or an object comprising: - an ultrasonic transducer;

- an amplifier operatively connected to the transducer; and

- a function generator operatively connected at least to the amplifier.

2. Device as claimed in claim 1, wherein the transducer is placed in a packed bed of particles.

3. Device as claimed in claim 1 or 2, wherein the function generator produces an alternating voltage with a frequency in the range of 1 Hz to 250 kHz or in the range of 250 kHz to 100 GHz.

4. Device as claimed in any of the foregoing claims 1-3, wherein the amplifier is an audio amplifier.

5. Device as claimed in any of the foregoing claims 1-4, wherein the amplifier is an end stage of a transmitter.

6. Device as claimed in any of the claims 1-5, wherein an audio transformer and/or an antenna tuner is arranged between the output of the amplifier and the transducer.

7. Device as claimed in any of the foregoing claims 1-8, the device suitable for transmitting ultrasonic energy to a quartz tube in a UV disinfection reactor, to a crystallizer, to a polymerization reactor and/or to a reactor for producing functionalized particles, including particles with good adsorption properties or catalyst particles.

8. Device as claimed in any of the foregoing claims 1-7, the device suitable for dispersing ozone in a liquid and/or for disinfecting ana purifying liquids.

9. Device as claimed in any of the foregoing claims 1-8, wherein the function generator produces a distorted sine function and/or a distorted square-wave voltage, and wherein the energy generated by the function generator consists of more than 0.1' distortion.

10. Device as claimed in claim 9, wherein the signal supplied by the function generator is amplitude-modulated and/or phase-modulated and/or frequency-modulated.

11. Device as claimed in any of the claims 1-10, wherein the amplifier consists of at least a transistor and/or vacuum tube, and wherein an end transformer is applied for the purpose of adapting the impedance of the end stage to the impedance of the transducer and/or for distorting in the desired manner the signal which controls the transducer.

12. Device as claimed in any of the claims 1-11, wherein the amplifier consists only of a transistor or a vacuum tube and a transformer.

13. Device as claimed in any of the claims 1-12, wherein the amplifier consists of a FET or a vacuum tube or a transistor on the one hand and a transformer on the other, and wherein the FET switches only in the positive alternation of the supplied alternating voltage.

14. Device as claimed in claim 13, wherein the FET or the transistor or the vacuum tube switches only a part of the positive alternation of the supplied alternating voltage.

15. Device as claimed in any of the claims 1-14, wherein the frequency of the alternating voltage over the transducer is at least a factor 2 higher than the alternating voltage supplied by the function generator to the amplifier.

16. Method or device as claimed in any of the claims 1-15, wherein the power supply lor the ultrasonic control can be regulated in the range of 0 V to 400 V, preferably in the range of 0.1 V to 50 V.

17. Device as claimed in any of the foregoing claims 1-16, wherein the power supply is poorly smoothed so that an amplitude-modulated or otherwise modulated signal is fed by the function generator to the amplifier.

18. Device as claimed in one or more of the foregoing claims 1-17, the device comprising a network of diodes and capacitors and resistors directly connectable to the mains electricity such that a high voltage and a first direct voltage are created, wherein the first direct voltage is lower than the high voltage, and wherein a second direct voltage is created by bringing down the first direct voltage with a voltage regulator so that the second direct voltage is lower than the first direct voltage, wherein the second direct voltage is employed for the purpose of providing a microprocessor with electric energy and/or the first direct voltage is employed for the purpose of amplifying a signal supplied by the microprocessor and/or the high voltage is employed for the purpose of providing an amplifier consisting of one or more FETs or power transistors with energy.

19. Device as claimed in claim 18, wherein the FETs or power transistors control a transformer.

20. Device as claimed in claim 18, comprising at least an ultrasonic transducer operatively connected to a secondary ceil of the transformer.

21. Device as claimed in claim 20, wherein at least a gas discharge lamp can be operatively connected to the secondary coil υf the transformer.

22. Device as claimed in any of the foregoing claims 1-21, suitable for simultaneously controlling disinfecting equipment, the device further comprising:

- a power supply which produces a direct voltage;

- a single microprocessor which produces a pulsed direct voltage, the frequency of which is adjustable; - at least two pre-amplifiers each comprising at least a transistor or a FET or a vacuum tube;

- at least two power amplifiers each comprising at least a power transistor or a FET or a vacuum tube;

- at least two transformers each comprising at least a primary and a secondary coil; and

- at least two disinfecting devices each operatively connected to the secondary coil of another transformer.

23. Device as claimed in claim 22, wherein with a single microprocessor at least an ultrasonic transducer and at least an UV-C lamp or ozone generator is provided with electric energy by means of software.

24. Device as claimed in claim 22 or 23, wherein with a single microprocessor at least an electromagnetic transmitter and another disinfecting device are provided with electric energy by means of software.

25. Device as claimed in any of the foregoing claims 20-24, wherein the microprocessor realizes the control for generating electric energy for powering the disinfecting devices and ensures process control, including opening of valves, controlling and/or activating of alarm signals.

26. Method for transferring ultrasonic energy for treating a fluid and/or an object, comprising of providing a device as claimed in one oi more υl the cldiiπs 1-25.