ELECTRICAL CONVERTER

Abstract: Electric power amplifiers produce as a rule the output voltage by taking up the voltage between a continuous voltage and the output voltage by means of a component with controllable voltage drop. When the output voltage is an alternating voltage a transformation of the continuous voltage can instead be made by a transformer (14) with variable ratio. The position of the connecting point of the transformer winding can be controlled mechanically or electrically and the contact at the point can be attained by mechanical contact, electrons, ions or charges in semiconductors of different kind. For example electrons can be guided to determined turns on the coil by giving a cathode (16) a longitudinal voltage drop from the heating voltage (18) and by connecting the input voltage to the grid, making it possible for electrons to arrive at a part of the coil, while the voltage of the coil further limits the electron current to a small part of the coil. By means of the design of the transformer the input signal can be converted to arbitrary output signal for example harmonics and saw tooth voltage.

Description: Electrical converter High-efficient amplifiers, which are made of partial amplifiers have been shown to give extremely good linearity besides high efficiency. Notwithstanding this it is desirable to make the technique with partial • amplifiersmore-continuous, so that the crossover distortion can be completely neglected. This is what is the most caracteristic for the constructions, which shall be described here. At the same time it is possible to completely control the distortion and thus it is possible to make wanted degree of nonlinearity even very extreme ones. This construction is thus a more general technique for conversion, where for example electrons are guided to certain turns on a coil. The description contains the following figures: 1. Coil with mechanically controlled contact. 2. Section of the coil. 3. Position and voltage displacement. 4. DC/AC converter with brushes. 5. 6. Brush constructions. 7. Converter with transistors. 8. Converter with transmission gate. 9. Converter with the transistors at the same potential. 10. Converter with electron current. 11. Catode. 12. Grid. 13. Converter with electron current and accumulators. 1^-16. Anode coil with anode rods. 17-21. Converter with electron current and magnetic core. 22. Spiral coil in integrated circuit (IC). 23. Contact methode in IC 24. Converter for the third tone. 25. Converter for the second tone. 26. Converter 24 with electron current. 27. Converter 26 with anode. 28. Converter 26 with grid rings. 29-30. Converter with coupling and series transistors. 31. Converter with collector spiral and emmitter spiral. 32. Converter with spiral formed cathode. 33. Oscillator with electron currents. OMPI /., IPO Q. 34. Spiral coil with the input voltage joining the coil. 35. The breake up of the coil by transmission gates. 36. Diagram for the breaking of the coil. 37. Diagrams of the efficiency. 38. End of the coil with contact branches to positive, negative and zero voltage. 39. Coil end with contact branches to many voltages. 40. The breake up of the coil by field-effect transistors. 41. Converter with bipolar transistors. 42. Layout for 41. 43. Converter with partial amplifiers. 44. Voltage dividers with transistors. 45. Converter v/ith inverted input voltage. 46. Converter with tube-formed semiconductor. 47. Converter v/ith IC in coil. Figure 1 shows in double section a conversion from a constant voltage E ■ to an alternating voltage in load R„. The converter is made of a number of concentric coils. They can have different shapes for example toroidal, but in the figure they are supposed to be straight. There can be a core through all coils or no -but to simplify the theories it is supposed that the magnetic flux B, which is inducsed--by currents in the coils allways pass through all the coils. Of these coils 1 and 2 have the same number of turns and are connected to a linear commutator, or the coil itself is a commutator as in an ordinary adjustable transformer. Coils 1 and 3 are connected in series and coil 3 is part of the total coil and has no commutator. In the same way coil 4 is connected to coil 2. Coils 3 and 4 have the same number of turns and are connected to each other so -that the midpoint, which is obtained is conected to voltage E . Coils 1 and 2 are not connected to each other, but they are geometrically placed in such a way, that one and the same brush 6 without break can slide over the free ends of the coils. Coils 1 and 3 will be push-pull turns, whereas coil 5 is connected to load R„. Voltage E is connected between brush 6 and the midpoint between coils 3 and 4. In an ordinary push-pull circuit, the ends of the coils are connedcted to for example transistors, which take the voltage difference between the constant voltage E and the alternating voltage in one of the push-pull coils. The power dissipation in the transistors can be eliminated by a O PI_ , IPO variation of the transformation in proportion to the alternating voltage. This is obtained by sliding the brush so that more or less of coils 1 and 3 are connected to voltage E when the output voltage shall be positive, whereas the brush slides over to coil 2 and connect more or less of coils 2 or 4 to voltage E when the output voltage shall be negative. How the converter works will now be described assuming that a sine voltage shall be obtained, when the brush has an harmonic movement caused by for example a crank and a rod driven by a wheel 8. The question is how tight and thick the wires of the coils shall be when they are commutator. Theposition of the brush can be written x = Xsinωt (1) and thus an alternating voltage with an angular frequency - can be obtained. X is so large that the whole coils 1 and 2 are covered, at which the smallest number of turns, which will be connected are coils 3 and 4 with N turns. The alternating voltage which fits to this movement of the brush can be described by a sine function and thus the flux shall be a cosine function 0 = 0 ocosβt (2) The induction law makes the voltage in the coil 5 u„ = N„0 wsinut (3 ) 2 __ o the current i„ = NL0 ωsinωt/R- (4) and the instantaneous power p„ = • N 0 tu sinu_t/R„ (5 ) 2 2 o 2 The voltaq -e in coil 3 will be u = No 0o tosinut (6) The induced voltage between the brush and the midpoint will be e = N0oωsinωt (7) the turns shall now be chosen so that e the whole time is the Combined with (1) the position of the turns is given by because Eo = Noωøo (9.1) The positions of the turns are shown as an example when N = 4 i figure 2. The relation between time t the position of the brush x and the turns N is sin»t = x/X = No/N (10) When x is small the turns are very tight and the wire very thin, which is impossible to have in practice. The current in the used turns is obtained from Ni = „i„ (11) at which the current interchanges from the left to the right coil when the brush pass origo and the voltage changes sign. For resistive load which is supposed, the current in the right coil will be positive which means that the formulas are valid if i>0. (11) and (4) give The formulas will be simpler if load R ? is transformed to coil 3 or 4 by R = (N 2 /N 2 ). (13) O O Δ Δ The current in coil 1 is then 1 = (14) If coil 3 is the output and is loaded by R the load current will be io = Ni/No = Iosinwt (15) To detεrmin the current density and the resistive voltage drop in the coils., width h of the wires are needed when they also are commutators The maximum current density for a wire with height h is and nearly constant along the wire. The resistance of coils 1 and 3 2 can with a small modification of the width of the wire to b = XNo/N be calculated from the length 1 = 2KDN giving dl = 23CDdN to The voltage drop transformed to coil 3 is then « . No pr2ffDNo 2 Io ,..., ΛU = ri W = 3hX (19) which is constant if N is allowed to be infinity. If the voltage drop ri was constant it should be a reduction of ι .- voltage E . Δu is instead a reduction of the output voltage thus giving crossover distortion when the voltage is --passing zero. This can be perfectly compensated by a small axial move of the coils and a reduction of the number of turns to R 2hX N max = N o27TD (20) which is the new origo when coil 1 is moved to the left and coil 2 to the ri The resistance (18) as seen from coil N is then o r = N 2 /N 2 r = R (22) o max o max o This means that the coil shall be moved so that one gets the resistance one is going to connect to coil N . See figure 3. If the coils are not cut in origo but nearby a distortion is again obtained, which yet is small. The voltage steps between the segments, which is maximum E /2N ,can be-'as serious when the commutating in figure 1 is used. Other commutating methodes will be described and these eliminate or reduce the voltage steps. By cutting off coils 1 and 2 and letting the wires from them partly go side by side making currents in booth coils for zero voltage a difference current at the output can be obtained and being zero without extremely high resistance. If the brush is rotating for example on a toroidal coil it will withstand the acceleration forces better. Winding coils 1 and 2 farthest outside, double,.correct turned and with correct pitch the coils can be commutator. Another possibility is to only use coils 1 and 3 and with, a commutation as in figure 4 use pole switching of the constant voltage E. By means of a rotating arm 20, with coupled brush pairs in the ends, the poles of the battery will be coupled from a half circle formed collector ring 22 to a - segment ring 21-, which is connected to the ends of coil 1. The segments in the commutator can be made of rods, which are stacked with isolation in between, so that the brush 6 can rotate and slide against the surface obtained. All equally formed segments are connected together so that every quadrant is connected to coil 1. The outer end of coil 3 is connected to a complete collector ring 23, which by means of the second brush pair is connected to the opposite half circle formed collector 24, which is connected to the second pole of voltage E. A methode to obtain commutating direct to a coil is shown in figure 5 where an isolated dish 30 is provided with brushes 6, which are with conductors 31 connected to a conducting axle 32 with which the brushes are moved * axially within the coil. The isolation between the brushes is nessesary to avoid a short-circuit in the magnetic field. The dish can also be replaced by magnetic material and if it is conducting it can be built of segments in such a way that it is conducting radially to the brushes. It can be easier to let the coil be moving instead of the brushes. Figure 8 shovs how brush 6' is following the wire in the coil and thus moving spiral formed. OMPI In the technique of today it is of cause semiconductors, which shall be used to connect the constant voltage to the connecting points at coil 1. In figure 7 field-effecttransistors (FET) are used, which during the positive half period connect", a possitive battery 40 to the connecting points and during the negative half period connect a negative battery 41 to the connecting points. The current paths are closed by means of negative voltages at the gate of some of the p-chanπel transistors whos emmitters are connected to battery 40. By means of different bias voltages at the gates, the connecting point, which gives the most turns will be passed for a small input voltage U. , which indirectly is connected to all the gates and make the transistors succεsively conducting for increasing input voltage and making the last connecting point between coil 1 and 3 for the highest usable input voltage. The currents are switched off by means of diodes 44 between the collectors and connecting points to avoid paths to more than one connecting point. To avoid inverting the input voltage, n-channel transistors are used for connecting the negative battery 41 to some of the connecting points of coil 1. The current is switched off by diodes 45. The said bias voltage can for example be attained by batteries 42 and 43, respectively, and connected to the gates of the first and last transistors via voltage dividing resistances 46 and 47, respectively, to the transistors in between. To adjust the zero crossings the input voltage is biased by batteries 48 and 49, respectively, before it is fed to the gates. The function is the same as the mechanical one in figure 4 except for the use of two batteries instead of pole shifting. The converter works as a linear high-efficient amplifier and the output is for example the ends of coil 3. A some what different technique is shown in figure 8 which is a generator controlled by a clock signal. The connection of the constant voltage is made first with a bridge of for example transmission gates, which make a reversion of the poles to give the positive and negative half periods. The connection of the different connecting points on the coil is made with transmission gates 51, which are controlled from for example a shift register 52 connected in a ring and with an ONE circulating in the ring. Every time the ONE is connecting the end of coil 1, a control logic 53 gets a signal from the register. The outputs of the control logic control the transmission gates in the bridge so that voltage E gets shifted poles to the coils. The generator is a direct analogy to the mechanical one in figure 4. OMPI Figure 9 is in direct analogy with figure 1 and uses the same connection technique as figure 7. The transistors can for example be placed at the centre of the coils and be connected to the coil with many transistors on one turn so that a connecting principle in analogy with figure 5 is obtained. A connecting technique in analogy with figure 8 can be made by means of electron tube technique, which is shown in figure 10. The working principle is according to figure 1 , but the coils are exchanged to simplyfy the description. The connection to coils 14 or 15 is obtained by electrons, which come from cathodes 10 and 12. These are especially constructed as in figure 11 so that they get a lower potential at ende 16 and 17. The electron-producing part is a tube 12 with one end connected to the positive pole of a voltage source: 18 and with the other end connected to a conductor 11, with return through the tube and is connected to the negative pole. In this way a voltage difference of a few volts is obtained and will cause no magnetic field outside the cathode. When a grid as in figure 12 is threded over the catode, the electrons can be let through it from a longer or shorter part of the cathode by means of the grid voltage, which in figure 10 is • obtained from the one balanced secondary winding ofan input transformer 19. Outside the grids anode coils 14 and 15 are placed and they correspond to coils 2 and 4 or 1 and 3, respectively, and they are given positive potential from battery 13 connected to the common point of the coi s and with the neqative pole in the usual way connected to the cathodes for example to conductor 11. The output from the amplifiers can be made from the ends of the coils, connecting points on these or with an external coiL Without input voltage the grid-cathode voltages are zero at the ends 16 and 17 of cathodes so that equally great currents are fed to the ends of the coils giving the output voltage zero. With input voltage the first - grid is positive and the second grid negative causing in the second grid a cut off in the electron current. Instead the grid which got positive voltage will let through electrons from part of the cathode in proportion to the input voltage. With the correct load of the coils the voltage at the inner end of that part will be low, while the end of the coil will be negative causing the electron current to be cut off there. Is the input voltage futher increased, the electron current will go through the grid nearer and nearer to the centre, and the longer the part of the coil will be negative and block the electron current, which the grid otherwise would allow to pass. When the polarity of the input voltage changes, the electron current will go to the other coil instead. By spreading the windings unevenly, the linearity of the amplifier can be adjusted. By means of bias voltages on the grids or by πonemitting part at the inner end of the cathode, the zero passage of the output voltage can be adjusted. This effects the efficiency and the loading of the input from the grids. Until now the influence on the electron current from the agnetic field caused by the magnetizing current which is i = nø/L (23) From formulas (2) and (8), 0 and N are obtained and the inductance is L = AN 2 /1 (24) Generally both the electric area A and the length 1 is a function of N, but let us assume these as constants, making the magnetizing current 2 1W0 sinjt cosϋt E μ At 2t_)L To o o r- On the output this current is i = —;—cos«*Jt (26) om ιuL o Using electron tube technique, the magnetic field can influence on the possibility for the electrons from the catode to reach the wires of the coils. The electrons are moving in a part of circles and when it reaches a half-circle, this will saturate the current. The maximum magnetic field will be B = 0 /A = E /N ωA = μ N I /I (27) o o o o o o om The radius of the circle is obtained from the knovn formula r. =mv/eB (28) where v is obtained from the enery of the electrons when they leave the 2 cathode or about a few electron volts mv /2 = eV (29) e The diameter of the electron paths shall be less than the radius of the coils maximizing the current to Concerning the noise of the amplifier, it can be said that this is caused i. g. by the statistical choise of turns the electron make, causing partition noise, but the electrons will allways give output current and not as in a multi-grid tube, while the niose ought to be at least as good as in a mixer tube with many grids. V/ith mechanical coupling one can choose direct contact to the windings in a coil or via segments. In the corresponding way, the electrons can hit a number of anodes, which are connected to points on a coil. Also a mix of anodes and coils can be advantageous. Thus the innermost turn -__OMPI to which the electrons can travel on coil 14 and 15 can be determined by a not short-sircuit anode ring connected to that turn. Also the end of the coil can continue with anodes, which at low power work exactly as an ordinary push-pull amplifier. Anodes to intermediate turns can be used to attain special results, to be mentioned later in this description. The anodes are not nessesarly connected to coils. Figure 13 shows a DC connected output stage. The catodes and grids are made as in figure 10, while anodes 55 and 56 are rings. The electron tube systems are drawn ower each other as in conventional electron tubes. The grid in the lower system is controlled by the current in resistance 57 through which the whole anode current to the lower system is going. The load is fed from the common point between the cathode in the upper system and resistance 57. The other terminal of the load is fed to midpoint of an anode battery 58, which delivers successively increasing voltages to anode rings 55, so that the ring, which needs the highest grid voltage gets the highest anode voltage. The anodes to the other system is connected to resistance 57 directly for that anode ring, which needs the highest grid voltage but via batteries 59 for the other, so that successively lower voltage is obtained on these anode rings. The function is the ordinary one, which means that the lower system consumes current through the load, while the upper system drives current to the load. The difference is that in the upper system, the anode voltage used is increased with increased output voltage. The lower system gets an increased anode voltagewith decreased output voltage by exchanging the anode-catode voltage with batteries 59 and thus eliminating part of the anode dissipation. Batteries 59 are preferably accumulators, which after full charge can replace batteries 58. Anoter schema is that the lower system is exchanged with separate electron tubes the cathodes of which are connected to points on the lower half-part of battery 58 and with all the anodes connected to resistance 57. A solution, figure 14, of the problem with magnetic saturation by the anode current will also make it possible to use ferromagnetic materials to decrease the frequency range of an amplifier with an electron tube system. The anode coil 60 is provided with radially anode rods 61, which makes the paths for the electrons shorter, thus preventing them to return before they hit the anode. Between the rods, ferromagnetic rods can be placed without being an obstacle to the electrons. Mechanically the system can be built in many different ways but here is thought of a comb of metal which is wound as in figure 15. The magnetic system with rods 62 and flanges 63 and tube 64 are shown in figure 16. Another way to prevent magnetic saturation when using ferromagnetic material is shown in figure 17. A ferromagneric tube 65 of for example ferrite is surrounded parallel to the axis going cathode wires 66, which are current-fed from radially wires 67 and 68 at both ends of the ferrite tube. These radially going wires are connected to a rod 69, which is threaded through the ferrite tube and a metal tube 70, which is put round the rod. A grid as in figure 18 is threaded over the cathodes, which are directly warmed by DC. The grid has wires parallel to the axis, and if ring- shaped supports are needed, they are made of isolating material. On one side the wires are goibg radially to a metal tube 72 or a rod. Over the grids are threaded an anode coil as in figure 19 which shields the output coil as in figure 20. Round two such systems ferrite flanges 74 and a large ferrite tube 76 are put as in figure 21. The system is then working as in figure 10. If the current in the cathode wires are to • strongly magnetizing tube 65, the return wires can be drawn along the outer surface of the tube. Whenusing transistors to connect the coils,steps in the output voltage are obtained as with segments. A first method to reduce the steps is to connect many transistors to each turn. This makes very many connections radially from for example an IC containing transistors and control circuits in a rod at the centre of the coil. When the coil is small for example in amplifiers for high frequences, it can be put into the IC. Figure 24 shows an example of such an amplifier where the inner and outer ends of the square-shaped coil system is connected to the voltage source according to the same principal as in figure 1. The tight turns corre¬ spond to coils 3 and 4 while the sparse turns to which zero voltage shall be connected by transistors correspond to coils 1 and 2. The zero point, which is at the centre, is here fed to 8 equal cells 77, which contain transistors, which connect that turn in that angle, which is determined by the input signal which is fed parallel with the radial conductors from the centre. The voltage interval U , which the IC 3 max ' withstands before avalanche currents or bra down are achieved cannot be adopted by voltage E . Instead the voltage can be maximum E < (N /2N ).U (33) o o max max ' OMPI_ If the substrate voltage V = 0 the guard ring for the p-channel transistors in a CMOS-circuit is applied on this voltage, while the guard ring for the n-channel transistors can be set to U . The zero point for iiloX the coil system should then have the potential 0.5U + E . For N = 2N and U = 18 V, E will be equl to 4.5 V, which can be accepted for max ' o ^ field-effect transistors. In figure 23 the cell is magnified. At the top 3 conductors are passing, and these constitute part of the coil with N turns. After this follow 3 ~ o conductors with gaps between and to which the zero-point shall be connected. In the cell there is conductors below the coil, and it is assumed to consist of semiconductormaterial and is drawn in the figure with dashed lines. Besides zero-conductor 0 and signal-conductor S, a bias voltage F is applied which is distributed between the different gates such that the coupling to the different turns will occur at correct signal level. The dotted square is a p-pocket, and within this the connection diagram has partly changed to a circuit diagram showing field effect transistors connected to the zero-conductor via diodes, respectively directly to winding turns. The gate will obtain signal and bias voltage from a voltage divider consisting of semi-conductor channels to the extreme right. The way of function is analogous to the amplifier in figure 9. Thyristors can also be used in the amplifier which will further increase the efficiency. The amplification technique as described in this description provides high efficiency and high linearity, but it is also possible to achive a controlled high-grade non-linearity and at the same time a high efficiency. Figure 24 provides an example of a converter fed with a sine voltage generating a sine voltage with a frequency which is thrice as high. In principle, arbitrary input and output voltages can be chosen, but the construction is most easily displayed with this conversion. At the bottom the fundamentel tone is shown with time vertically, and the brush position horizontally. At the centre of the figure the relation between the position of the brush an the output voltage of the third tone i seen, which is a lissajour figure. At the top of the figure the converter is drawn in diagram form with a zero-conductor 0, on which the brush 6 is sliding at the same time providing contact to windings marked with crosses and rings. Constant voltage E feeds the centre point on a winding with 2N turns. This winding has no possibility of contact with the brush, but its ends are connected to winding turns in the x-position corresponding to maximum and minimum voltages, respectively. On the contrary there are winding turns implying that the voltage over N will be reduced in the desired way in the position where the brush is. Current in winding marked with crosses will generate positive output woltage, while rings will provide negative output voltage. It comes quite natural to use that phase of the harmonic, which is given in figure 24, but other phases will lead to the fact that the lissajour figure will have loops so that the same coils cannot be used when the brush mowes to the right as when it mowes to the left. Figure 25 shows the phase which can be used for making a conversion to the second tone. Of cause it is quite possible to generate the second and the third tones simultaneously, but no futher ones. Figure 26 is a converter of electron-tube type as in figure 10, but the coils are made for the second tone. The grid-cathode system is in principle unchanged, but delivers electrons at the centre, when the input voltage is 7ero. Besides the windings from figure 25, there is a coil 80 with its terminal fed with continous voltage E and tuned by means of a capacitor to the fundamental frequency. The output for the second tone is also tuned. By means of combined grid and cnode-coils 81 and 82, the fundamental frequency is obtained as in figure 10, but at the same time as earlier described, part of the winding turns on coils 81 and 82 is blocking the electron current even to the coils to the second tone so that only a limited section will deliver electrons whereby the efficiency is increased. By using an other division of the harmonic windings, and possibly a variable coil diameter, the harmonic can also be obtained, but in that case current must be counter-balanced between the two output windings, which may reduce the efficiency. This construction is shown in figure 27, where 83 is an anode consuming current during the zero crossing of the input voltage. When the input voltage increases, it reduces the influence of the current on the output voltage, since current will flow to coil 84 providing opposite polarity at the output. When the input voltage increases futher, the electrons move to coil 86, and then coil 84 becomes heavily negative, such that no current will flow to this at the same time as anode 83 will become wholly or partly blocked, whereby the current to coil 86 will be predominant so that the peak of the polarity-reversed part of the sine voltage will be obtained. Figure 28 shows another possibility to limit the electron current to one point. Screen-grid ring 88 coupled with diodes obtains positive voltage via resistances. Each of the screen-grid rings is connected to control- grid rings 89 azimuthally displaced between screen-grid ring and control grid. The rings are open in order not toshort-circuit the magnetic field. Since the control-grid permits a current within part of the cathode from origo to x, a screen-grid ring ot x will obtain low voltage, which will be forwarded by means of diodes to the control-grid rings down to origo, such that the * electron current within a region extending from origo to the neighbourhood of x will be blocked. Figure 29 shows a similar construction with field-effect transistors in an IC technique. Within the continous lines, there are e. g. N-doped layers in a silicium plate, while the dotted lines are marking conductors and gates isolated by means of silicon dioxide, except where there are contacts with the layer below, which is marked v/ith crosses. Alonq a lonq emitter 90 common to several MOSi-transistors, a direct current is fed such that different bias voltage is obtained to a αate 91 alono the one edge of the emitter. Along the same edge, there are a number of collectors 92 which at their other ends are changeα to emitters 93 in transistors, the collectors 94 of which are connected to the load e. α. to the connecting points of a coil. The gates between emitters 93 and collectors 94 are connected to adjacent collector, e. g. tne second next collector 94. When e.g. an increasing inpαt voltaαe u. is applied on the long αate 91, a transistor at tne one end, e.g. to the riqnt, starts conducting whereby current will flow to "the coil end and on to constant voltage E . The seμatated transistors are conducting, since the gates obtain voltage via the connecting points of the coil. When the input volta y e increases such that several transistors on the long emitter becom conducting, the voltage on the connecting points at the other' end of the coil will stop conducting. In this way only a few conecting points on the coil will be connected, and there will be no short-circuited turns. In order to have the connecting points of the coil coupled at correct input voltage, the emitter has varying resistance, e.g. by varying sections along its length. Another methode to achieve step-by-step coupling of e. g. connecting points of coils is shown in figure 30. A gate 96 of e. g. doped silicium common to several coupling transistors of n-channel type, below which are placed emitters 95, also these common to several coupling transistors, but working towards several collectors 97, has obtained varying bias voltage towards the emitter by having a current flow through the gate. At the same time the gate will obtain input voltage, since the current flows from e.q. a p-channel transistor 101 connected to a positive battery voltage and passes on to an n-channel transistor 102 connected to a negative battery voltage. The input voltage passes to the gate of transistors 101 and 102. Collectors 97 of the coupling transistors are connected to emitters 98 on series transistors of p-channel type. Their collectors 100 are connected to e. g. terminals on coils, at some end connected to constant voltage. The series transistors have a common gate 99 and are fed from transistors 103 and 104 in exactly the same way as the coupling transistors from transistors 101 and 102. However, gate 99 ought to have a more negative voltage level, which can be achieved by making transistors 101 and 104 largerthan transistors 103 and 102. When the input voltage is zero, the first couplinq transistor next to 101, will be conductinq. Should the input voltaqe increase, the next couplinq transistor will be conductinq, while the first couplinq ctransistor is low-resistive, but while its series transistor has broken the current. On the other hand the second series transistor is still conductinq. With increasinq input voltaqe, the current flows in the coupling transistors with higher and higher numbers of order. The guard rings usually needed around the transistors are not drawn in the figure, but may somewhat modify the circuit solution. Figure 31 shows how to couple, in an integrated circuit, connecting points on a coil 105 where they are placed closer together than one turn. In a spirale at the centre, emitter 95 is wound up and along this one, gates 96 and 99 are going parallel, as well as the input voltage to transistors 102 and 104. The connections to the coil run radially from the collectors in the internal spiral system. By means of e.g. ferrite mantel cores, the inductance of the coil and possibly also its Q-value can be increased. In the core there is a hole for the internal spiral system, but immediately outside the spiral system the core is tube-shaped 106, such that the magnetic field will pass through the silscium plate, where the conductors are radially.In the periphrey 107 the core closes. There are other forms of converters with ciols. Fiqure 32 shows a coil with a bifilar winding of qood conductinq material 111 and a wire of cathode design. The heating voltage is applied between the wires with cathode wire 112 turned towards the inside of the coil. A coil futher inside constitutes control grid 113. At the centre of thϋ coil, anode 114 is placet and has the form of a core of e.g. conducting ferromagnetic material. If all the wires are qoinq tiqht toqether no alternatinα voltaqe will arize, but the heatinq voltaqe will simultaneously constitute a • biasing gri'd-voltage decreasing along the wires. The amplifier works .in principle like the one half in fiqure 10, but with the difference that the electrons are moving in the opposite direction. Outside the coil system there is a cathode 12 and a grid 29, and winding 111 is utilized as anode. The grids obtain input voltage from a balanced winding on transformer 115. The output voltage can be obtained by a winding on core 114, or directly from the end of the bifilar winding. An oscillator using a helically-wounded cathode is shown in figure 33. A battery 116 provides heating voltage between the wires at the centre of a coil, which is bifilary wound with cathode materials 117 and 118 in the wire, when it runs in the internal layer and in the ends. The heating voltage is a constant voltage, and due to this fact it will be possible . to give the cathode coil a higher voltage at the centre than at the ends. Inside the cathode coil, there is a grid coil 119 with the same windinq direction and the same number of turns, and at its centre it is connected to the negative pole on the heating voltage. At the centre of the coil there is an anode rod 120 having, positive voltaαe relative to the centre of the cathode. The output voltage can be obtained either directly from the catode or from a separate winding 121 around all the coils. If a magnetic flux passes through all the coils, all of them will obtain an alternating voltage increasing outwards from the centre of the coils as in the diagram, where U. shows the cathode voltage having a nee at the centre, but for the rest is declining linearly with the distance from the centre. This implies that the grid coil will stop electrons from the cathode coil to the anode rod in the centre region, but the electrons would be able to pass the ends. By adding some turns at the centre of the grid coil, the one of its end will obtain higher and higher voltage and . allow the electrons t.o pass, while the other end is blocked, but when the ende of the cathode and grid become more positive than the rod, the electrons will be blocked anew, such that a disk of electron current will move within the coil, which is shown in the diagram, at the bottom. Since the extra turns on the grid coil provide positive feedback, the whole ^JR£4 OMPI / * . Y/IPQ system will self-oscillate with hiqh efficiency ana small harmonic content. A transfer of this system on semiconductor technique in integrated form is shown in figure 34. This is an amplifier of CMOS-techπiαue. The inout voltage passes in a conductor, which constitutes the gate in parallel with the conductors, which at even intervals changes to p and n-doped bands, respectively, which constitute:emitters in the transistors. The varving voltage level of the emitters is obtained by connecting the two ends of the conductors to a positive voltaqe 121 and to a negative voltage 122, respectively. The collectors to the transistors are connected to battery 123, should it be an π-channel transistor, and to battery 124, should it be a p-channel transistor. The collectors follow radially in the spiral parallel to the quard rinqs which are drawn in the fiqure and which are connected to batteries 125 and 126 provicjiπq still higher voltage. The radial conductors can be coupled toqether either at the centre or in a closed ring outsode the whole system, where the magnetic field is zero. The magnetic field runs, according to the figure, in e. g. a ferrite core and passes the semiconductor plate in rings 127 and 128, respectively. Between the constant voltages the decoupling capacitors 129 may consist of semiconductors, oxide layer and conductor. The system as described here is a CMOS-stage system with different bias voltages on the emitters such that they connect the spiral at the correct point to battery voltages 123 and124, depending on the size and polarity of the input signal. With increasing input voltaqe the connection point'on the spiral will be more and more close to the periphery. Braking the connection points exceedinq the battery voltaqe can be done with diodes as in fiqure 23, or with some more transistors as in fiqure 29 and 30. The outermost turn on the spiral is not connected to any transistor, but is coil N which also can be used c as output, but separate turns in the ferrite core can also be used. When transistors at"the end of the coil are closed for small inσut voltaαes and aσain broken when the inout voltaαe is futher increased, the voltaqe at the open end of the coil will increase and can be higher than the breakdown voltage. The problem is illustrated in figure 40, where 0 is the earthed end of the coil, and in its dead state it lies on zero voltage up to the end A. The transistor at the end of the coil can increase the voltage on the coil so that it will lie between 0 and B. The coil and the voltages are also to be found in the schema fiαure 35 where a brush connects the connection points of the coil to positive or neqative constant voltages. In order to reduce the voltaqe on the coil, this can be OMPI broken at some points marked as transmission gates. The break point must have been passed by the brush before it is allowed to break, and this is futher illustrated in figure 36. Before the end has reached the overvoltage, e.g. 2E, a break must have occured, e.g. at point C on the coil when the end has reached voltage D. The broken part may be neglected while the new end increases.to voltage G, whereby the coil is also broken at point K, etc. When maximum voltage is obtained, the last brake point has reached voltage 2E, whereby the voltage over the coil N has become E. Those voltages at which the transmission gate shall break or close are marked with small horiz. dashes. The broken coil will obtain voltages as shown by the lines having the same inclination as illustrated by coil N . o When the coil must be broken in order to prevent overvoltages the question is what ratio N /N and how many break points will be needed to obviously reduce the losses. The calculation is carred out with the assumption that a coil is earthed at its one end as in figure 35, and that the rest of the coil can be connected to positive or negative voltages to provide a sine voltage. The end of the coil cannot be connected directly to these ' • ' voltages, instead a transistor shall have to take up the requied voltage drop. In figure 27a is shown how efficiency n will increase when the turns N of the coil increases relative to the winding turn N at full deflection. The phase angle ωof the current has been changed step by step, and the increase of losses with the reactive power is remarkable. If also the earth point can be used when the load is reactive the efficiency increases noticeably. This is snown in figure 37b. When N /N =1 and ψ - 0, a quit conventional amplifier class B is obtained. What is perhaps is most notisable is the fact that the efficiency already for N /N - 0.5 has increased so wery much. It is 97.3 % for active load, and 90.8 % for ψ ~ 45 , which implies that breaking the coil will be necessary possibly at one singel point. The current requid to flow through the break point will become small so that the break in itself will not make too high demands on the components. Figure 38 shows how an amplifier at the end of the coil can be built of field-effect transistors, which are specially good to establish coupplings since they have no saturation voltage. An ordinary complementary final = stage is connected between the coil and the two continuous voltages. In order to reduce the need of_:bias current, there is a current way to earth OMPI Λ, V71PO via two complementary transistors coupled in parallel. They are made conducting around zero voltage in the coil by means of voltages to the gates via resistances 134 and 135. For positive input voltage, the p- chanel transistor is blocked via a diode to the gate, while the n-channel transistor is blocked via a diode from the coil. For negative voltages - there are two other diodes blocking the transistors. Reactive currents that are relatively largest around zero voltage will now have a short way to earth. The described coupling can be modified to figure 39 such that it will be able to reduce the crossover distortion of final stage 136, 137. By instead let, till now parallel coupled tranistors pass to each small constant voltage , and with a suitable proportion of the input voltage, block the one transistor the other will help the final stage to deliver voltage. The break of the coil, as earlier dissused in theory, can be doen in its simplest form as in figure 40, where two complementary field-effect transistors 138 and 139 lie in series with the coil and with the gates connected to battery voltage E and -E, respectively, such that the external part of the coil is broken when the voltage of the coil at that point passes some of the battery voltages. The voltage must not, however, increase such that the broken part of the coil will reach breakdown voltage at the one end, because its other end will be below voltage E as shown by line F - H in figure 36. Also bipolar transistors can be used with advantage to couple the constant voltage of a coil to its terminal. Figure 41 shows the principle diagram where a PNP-transistor has its input voltage and bias voltage at its base B1 as shown in the diagram. Another PNP-transistor in series with the first one and with inverted input voltage and another bias voltage at its base B2 feeds a positive voltage at the base of a coupling transistor of NPN type, such that a connecting point of a coil will obtain negative voltage within an interval when both PNP-transistors are conducting. By means of varying bias voltages at base B1 and B2, e.g. as in the corre¬ sponding circuit diagram in figure 42, where currents are flowing through the base lead-in wires, a number of coil thurnscan be connected at correct input voltage to a negative voltage. One problem is that several bases will consume current. In order to reduce load variations at the input, the one conductor to the bases has been given the form of a comb so that series-resistances will be obtained for each base. The two PNP-transistors OMP . P generally also reduce the input load as compared with direct control of the coupling transistor. In general, amplifiers with sophisticated gate functionc with synchron¬ ization between themselves can be plased at spiral conductors and couple them together with radial conductors such that a h gh-efficient amplifier or converter will be obtained. An amplifier built up by partial amplifiers is given as an example in figure 43. The partial amplifier according to the SE Patent Application 75 08220-6 is to be found in the diagram and and block diagram at the top. The complementary partial amplifier is denoted P_. The four partial amplifiers fatherest to the right have all of them the same input voltage and are connected to the same load. They form two overlapping complement¬ ary final stages with battery voltages E, and -E→ , respectively E. and -E, and can be used with advantage with a transformerless output, whereby the crossover distortion will be eliminated and the reactive power mastered, but here the partial amplifiers are connected as earlier to the ends of a coil. Two other partial amplifiers work with only one current direction between → = 0.5E-, and E, , respectively -E. and -E, on a connection point one fourth closer to the centre of the coil and with tree fourth of the input voltage. Two futher partial amplifiers work between E„ = - E, and E,, respectively -E„ and -E, and half the input voltage. If the last four partial amplfiers are replaced by many amplifiers at the crossing between spiral conductors an analogy to electron tubes with anode coil or cathode coil or both will be created. Voltage dividers for the supply voltages to the gates can be made as in figure 44 , where a number of n-channel transistors connected in series obtain their voltages to their gates from a voltage divider consisting of p-channel transistors connected in series, obtaining their voltages to their gates from the first voltage divider. By means of voltages between the two ends of the voltage dividers, their resistances can be adjusted. It may be advantage to generate bias voltages to e.g. coupling transistors such that these will close and break without diode or series transistor. Figure 45 shows one metod, where successively increasing bias voltages are added to the input voltage, and succesively decreasing bias voltages are added to the inverted input voltage, the summated voltage of which will pass in pairs to minimum gates (analogous AND-gates) which deliver the smallest of the two voltages to a coupling transistor. The coupling causes the coupling transistors to close in proper order with increasing input voltage. If a sine voltage is used instead of a constant voltage for the supply of power, some mixing or modulation will arise in many of the constructions described here. • Semi-conductors on sapphire are excellentfor high efficient converters of this kind, because the isolation problems are substantially redused. At very high frequencies, inductances can be obtained, which have not the- form of a coil e.g. rod or u-form and may continue in the form of an antenna rod or a folded dipole, but the principales of the described arriDlifiers, or oscillators or harmonic αenerators can be aDDlied also to simple qeometrical forms like those already mentioned. Instead of plane coils, cyllindrical coils may be used on semi-conductors of thin tubes containinq a ferrite rod and with their base and emitter in form of lonqitudial bands at the inside and the coil as collector at the outside, but the crystal direction imply problems, and the manufacture will not be easily performed at todays ' state of the art. Strictly physically, the magnetic field can be made to function correctly by allowing base bands and emitter bamds to reach a bit outside the ferrite rod and at this point be poupled toqether in rinqs by threadinq on two ferrite dishes an placing the coil between them. The external peripheries of the ferrite dishes car. be joined toqether by means of a ferrite tube. Instead of the semi-conductor tube, this can be simulated with advantage by means of discrete semi-conductors. Also new serai-conductors of plastic might be used (figure 46). A capsulated IC can be placedat the inside and be connected to a coil as in figure 47.

Claims: Claims 1. Electrical converter characterized in a conductor formed as a coil (inductance) (1, 2, 3, 4; 14, 15; fig 19; fig 22; 81, 82, 84, 86, 87, 105; 111, 112, 113; fig 34; fig 35; fig 45-47), three connecting points on the conductor one (6) of which obtained for example by a sliding contact (fig 6), a number of switching contacts (fig 4, fig 24), electrons in vacuum ( fig 10", fig 13J fig 17-19, fig 26-28, fig 32), ions in gases or charges in semi-conductors (fig 7-9, fig 29-31, fig 39-47) and is controlled movable to points or sections along the conductor, so that a voltage (E ) between a fixed connecting point an the movable connecting point and another voltage between the two fixed connecting points at every time are related to each'other in a wanted relation. 2. Electrical converter, as claim 1, characterized in that the movable connecting point (6) on the conductor is produced by an electron current guided to a section of the conductor from a long catode (12) placed in the centre of the coil (15), and with londitudinal voltage drop from for example its heating voltage (18), so that a grid (fig 12) round the cathode with proper voltage let through electrons from the one end of the cathode on to a controllable part at the cathode, controlled by the grid voltage, and another grid with longitudinal voltage or that part of the toil, which could get current through the grid but has got induced negative voltage, which is blocking the current from the same end of the catode up to the controllable part. 3. Electrical converter, as claim 1, characterizedin that the resistive voltage drop in the coil is compensated by a constant bias voltage (fig 3) to the input signal or a constant displacement of the controllable connecting point on the conductor. 4. Electrical converter, as clame 1, characterized in that in a balanced converter made of either two magnetically coupled coil systems (fig 10) or a coil system with complementary semi-conductors (fig 9), the crossover distortion is eliminated by controlling voltage and current at the same time to the two coil systems, respectively to two complementary semi¬ conductors, and by varying the resistance or the coil by for example decreasing the area of the conductor. 5. Electrical converter, as claim 1, characterized in that only one coil is needed when converting from continuous voltage to alternating voltage by making a pole exchange from the continuous voltage by for example fix half-circle formed segments (22,24) connected to the continuous voltage (E which voltage via four brushes on a rotating arm (20) is alternating O Λ. WI connected to a collecting ring (23) in contact with the one end of the coil or to segments in contact with connecting points on a coil, and in the electronic case for instance with transmission gates (50) in a bridge connected to the continous voltage, which bridge is controlled by for example a ring counter (52) with a rotating ONE, which every turn exchanges the transmission of the bridge when the ring counter at the same time control the transfer of the continous voltage to the connecting points of the coil by means of transmission gates (51). 6. Electrical converter, as claim 1, characterized in that the mov ent of the controllable connecting point is made in steps to points where transistors (or tubes) are contact making means, coupling transistors, in series with diodes (44), and that the control is obtained by the voltages on the bases on every transistor, which voltage is a sum of the input voltage and an individual bias voltage (46, 42, 48) which convert a continuous voltage (40) to output voltage across the coil ( 3) and when no diodes are used, to the input voltage is added succecively increasing bias voltages (fig 45), but also to an inverted input is added succεsively decreasing bias voltages, and that these voltages in pairs are connected to minimum gates (analog AN'D-gates), which outputs are connected to the fcases on succesively situated coupling transistors. 7. Electrical converter, as claim 1, characterized in that (fig 46) for example the conductor of the coil is made of aluminum on a p-doped band on a tube of semi-conductor, and that the components to the connecting points on the conductor is made ofdiodes in series with transistors .achieve by n-doped rectangles being collectors and in contact with the band making diodes, under the rectangles p-doped longitudinal bands longer than the coil and being bases, under these bands n-doped longitudinal bands being emitters, that the magnetic flux flows in a ferromagnetic rod inside the tube of semi-conductor material,which rod is longer than the coil but shorter than the base and emitterbands, and flows futher in a yoke outside the tube, which yoke is for example made of a cylinder with flanges with hole, which fit between the ends of the coil and the ends of the tube, which is provided with conducting rings for the connection of the base and emitterbands, which can have longitudinal currents to obtain bias voltages. 8. Electrical converter, as claim 1, characterized in that a cathode wire (112) together with its return wire (111) and grid wire (113) together makes a coil and deliver current from a point, which position is < determined by connected grid voltage, to an anode of ferromagnetic and conducting material in the centre of the coil and that a cathode with longitudinal voltage drop outside the coil, which cathode delivers an electron current from a point, which is controlled by a grid (29) to reach a wanted point on the return wire (111). 9. Electrical converter, as claim 1 and 2, characterized in that the cathode with voltage drop instead of delivering the current to a coil with conductive voltage drop, delivers the current to ordinary anodes (55), and that the voltage difference of the anodes is prodused by for example accumulators, which reduce or completely absorbe the ordinary anode losses. 10. Electrical converter, as claim 1, characterizedin that the anode coil is provided with anode rods (fig 14, 61) towards the cathode in the centre and in between which ferromagnetic cores are placed. 11. Electrical converter, as clames 1 and 2, characterized in that the cath is made ofaxially going wires (66) round for example a ferrite core (65), which wires are at the ends connected together at the centrum line and provided with warming DC and the grid (18) is formed in the same way, and that round this is put the anode coil (fig 19) and that a core enclose • the whole by a tube (76) and flanges (74). 12. Electrical converter, as claim 1, characterized in that the turns of the coil (fig 24-28, fig 30) are divided and distributed and cooperate with ordinary anodes (83), thus giving e.g. harmonics of the input voltage. 13. Electrical converter, as claim 1, characterized in * that the current ways to the coil is provided by semiconductor device containing a long emitter (90) with longitudinal potential drop from current, which emitter can emit by a gate (91) controlled current to many collectors (92) which deliver the current to a connecting point on the coil via series transistors controlled by other connecting points than tose to which the collectors (92 ) are connected. 14. Electrical concεrter, as claim 1, characterized in that current ways to the coil is provided by semi-conductor device containing emitter (95), which can deliver current to many transistors, which are controlled by gates (96) of for example doped silicon (fig 30, fig 42) or by bases (fig 41), which pass many transistors and are current-earring producing bias voltages, which together with the input voltage make more or less n-channel transistors with common emitter (95) conducting round the one end of the gate, while those with the said transistors series coupled p- channel transistors-by means of biased common gate with added input voltage make more or less p-channel transistors conducting round the other end of the emitter, so that some conducting choiceable vay is obtained to for example a rectangular or spiral formed coil or connecting point of a coil or base on a coupling transistor (fig 41). • 15. Electrical converter,- as claim 1, characterized in that current ways to the coil is obtained by a semi-conductor device in which the input voltage, gate transistors and coupling transistors follow the conductor of the coil (fig 34). 16. Electrical coverter, as claim 1, characterized in that the coil is broken up for example by transistors (fig 40) in sections when the broken section is not current carrying (fig 35, fig 36) and that the outer end of the coil can be connected to both positive, negative and zero voltage (fig 38) to reduce power losses at reactive load or that the crossover distortion is at the same time reduced during smal signals by separate balanced stages (fig 39) at the end of the coil, which is controlled and disconected by diodes from the end of the coil to the gates or bases.

Inventors: HOEGLUND LENNART HARRY ERIK, HOEGLUND, LENNART, HARRY, ERIK
Applicants: HOEGLUND LENNART H E, HOEGLUND, LENNART, HARRY, ERIK
Application year: 1982
Main classification: H03F1
IPC codes: H02M7, H03F1, H03F7