DE1289571B - AC linear potentiometer - Google Patents

Description

1 2

The invention relates to a linear alternating current wiper potentiometer connected to a common star point with one of the input voltage contacts a shunt, which another lying voltage divider, which results from an error in the voltage division ratio has cylindrical insulator wound with winding.

several, mutually constant distance 5 It is known in principle for potentiometers to Taps and consists of a grinder, eliminating this shunt between two to apply a voltage to several customer contacts, which are unchangeable from one another in terms of distance, which Has receiver contacts that have the same size and phase position as the voltage divider with the taps of the interact and with a voltage drop in the part of the voltage divider winding, Voltage derived from the input voltage so that it is between these two consumer contacts, are coupled that between the two outer Ab- so that the above-mentioned equalizing current is not recipient contacts in terms of size and phase that can flow. Between the two customer consoles Voltage is as between that of these clocks, a voltage is applied that of both pickup contacts bridged part of the input voltage is derived to each Voltage divider winding. 15 case to get exactly the same phase position.

A known embodiment of such an object of the invention is a linear alternating

Potentiometer consists of a largely inductive current potentiometer, which is as undisturbed as possible tion-free body wound with resistance wire, linear dependence of the output voltage on the on which the windings run transversely to the body, travel with constant input voltage. and an ao movable in the longitudinal direction of the body, which has a good resolving power and Contact that with a desired turn of the loading Automatic error in the linearity of the output voltage winding can be related and compensates for the gradations in the Spanso a variable tapping of the winding formation divider and equalizing currents between the edges. The consequence of this is that one of the input voltage contacts is caused. The first voltage, which is placed at the two ends of the winding 25 The object of the invention is a linear change, between one end of the winding and the current potentiometer, which is characterized by moving contact a part as output voltage that the voltage divider winding from an inductor received will. The potentiometer is designed in such a way that Wickdaß is low-ion and wound from resistance wire the movable contact always exists with at least one development, that of the input voltage from the turn the winding is in conductive connection, 30 conducted voltage through a separate transformer z. B. can be achieved that two mator is obtained that the number of customer contacts be used, which is greater than two in the axial direction of the contacts that the Abnehmerkon-body arranged at a small distance from one another via a corresponding number of resistors are. The output voltage changes for those with a correspondingly large number of connections of the secondary Device when the movable contact is galvanically connected to the transformer winding the body is moved, gradually. those are that which supply the changeable potential

In another known voltage divider, the output terminal is through the center tap of the seeine Secondary winding is formed of low ohmic resistance and that accordingly is used, which is located on a body that follows the vernier principle of the mechanical distance of the consists of a material of high permeability and 40 contact points of the taps of the voltage divider relay closed core is formed. When the input winding is slightly larger or smaller than the voltage is applied to the winding ends of this inductive distance of the consumer contacts, The second object of the invention is a linear

lays; the output voltage is in the same way as res AC potentiometer, which is marked by it described gradually changeable. 45 is that the voltage divider winding as

It is known in voltage dividers of this type, the transformer winding with several side by side sizes the steps to be reduced by the fact that multiple, mutually insulated partial windings rere sliding contacts are provided, which is designed in common that on a workpiece with high masam are moved along the body and are wound according to magnetic permeability that of are arranged according to the vernier principle. For example 50 voltage derived from the input voltage four contacts can be obtained on one of the distance three using a separate transformer, the turns be distributed according to length. Each sen primary winding is connected to the input voltage the contact is via a separate resistor and its secondary winding has several taps has a common neutral point for all contacts, which connects the partial windings of the voltage divider. In such a device, the 55 winding will feed, and its tertiary winding with the Combine the output voltage between the star point and the primary winding of another transformer The end of the winding is removed, but one is tied from the one on the voltage divider earth theoretical characteristic curve of the voltage divider devel- opment shiftable, representing the slider Speaking output voltage can only be obtained if the sleeve is made of a highly permeable material and if all the contacts with turns of the winding consists of 60 of a secondary winding connected to the wind non-conductive Connected. While the cone has stripped parts, which the lower intact Move from one turn to the next, alternating inductively coupled consumer contacts the actual output voltage, with these stripped parts in direct succession not linear, but due to the arrangement clocked with the partial windings of the voltage divider winding Contacts in the vernier principle correspond to the size of the voltage, so that a conductive connection is established voltage levels is reduced. In this known between the voltage divider winding and the Se arrangement receives the respective secondary winding from the contacts that the changeable bridged part of the winding through the output terminal providing potential through the supply

3 4

connection point of two resistors is formed, the voltage Vl is connected to the parallel-connected ends of these

both windings connected to the ends of the secondary winding are applied. The secondary winding

and that a vernier effect is achieved as a result, 3 5 of the transformer has four taps 5.

that the number of turns of the secondary winding is small- Each end of the secondary winding 3 5 and each of the

docile from the number of turns of the 5 taps bridged by it 5 is via a resistor 6 to one

Part of the partial winding of the voltage divider winding of the six contacts 7 out. All six contacts 7

deviates. are on a common slide 8 in the same

The third object of the invention is a linear, moderate spacing so that they share an alternating current potentiometer, which is characterized by being able to be moved along the body 1 in that the voltage divider winding consists of a toroidal transformer with the exposed wires of the winding, that the lungs 2 come into conductive connection. The voltage derived from the input voltage stood between two adjacent conduits a separate toroidal transformer 7 is chosen so that it is unequal to the winding whose primary winding is at the input connection distance of winding 2 or a constant voltage and whose secondary winding is several 15 multiples of this distance, so that the vernier has taps, which is achieved with the corresponding effect. In the example, six taps on the contacts forming the voltage divider bridge eight turns of the winding 2. Since the toroidal core transformer is capacitively connected in the manner shown in FIG. 1 are only connected to a schematic representation that illustrates the taps with one, it can be assumed that in the speaking number of distance-invariable practice the six contacts are connected to a large number of conductive strips that bridge on a winding. The turns ratio base plate made of insulating material are arranged, and the winding sense of the transformer 3 are selected so that the taps with a corresponding connection that the electromotive force is connected between the number of constant spacing strips the outer two contacts 7 A and 7 B equal and the which is movable on a second, opposite to the first 25 of the same phase position as the voltage base plate and in this way the drop in the part of the winding 2, which is arranged by these wiper insulating plates, is bridged by two contacts. This has the consequence that the output voltage supplying the variable potential is equal to the voltage drop in the part of the winding tap of the secondary winding of the voltage drop in the part of the winding tap depending on the desired position of the output terminal Is toroidal core transformation 2, which is connected by the integrally formed to the taps and that a nonius adjustment closed contacts 7 is touched. The effect is achieved in that the distance between the output voltage VO of this potentiometer is between the strips on the movable insulating plate and is less than the center tap of the winding 35 and than that of the strips on the base plate. 35 removed from one end of the winding 2.

The following are exemplary embodiments of the Po- If when using the potentiometer the con-

tentiometer according to the invention can be moved together along the body 1 on the basis of the drawing bars 7

described below. In the shows the, each of the contacts 7 is periodically

F i g. 1 schematically shows the perspective view of the following turns of the winding 2 in loading

and the circuit diagram of a potentiometer according to the 40 come into contact, so that the potential of this con-

first object of the invention, clocks is changed gradually. This has a

F i g. 2 schematically in a perspective view the change in the currents resulting from the different

mutually displaceable parts of a potentiometer-separated resistors 6 and the individual separators

meters according to the second subject of the invention sections of the secondary windings 3 5 flow, however

connection, 45 is the change in the tap 9

3 shows a longitudinal section through part of the output voltage taken lower than that at

F i g. 2 and the individual contacts 7 occurring voltage

4 shows the circuit diagram of the potentiometer according to the change. He also receives from the contacts

the F i g. 2 and 3, 7 A and 7 B bridged part of winding 2 practically

F i g. 5 the circuit diagram of a potentiometer according to 50 table no shunt, since the electromotive

the third aspect of the invention, wherein the force in the winding 35 is as great and of

Fig. 5 a and 5b show the transformers, which is in the same phase position as the voltage drop in

the circuit according to FIG. 5 are used, the one between contacts 7 A and 7 B

6 shows a perspective view of part of the part of the winding 2.

Potentiometer according to the 55 shown in FIG. 5 It is evident that in a known

Circuit diagram, resistance potentiometer that has a winding body

Fig. 7 shows, in perspective view, the main parts and a single sliding contact, the spandes Potentiometer according to the in F i g. 5 jumps in the representation that occurred at this contact when he was praying Circuit diagram. move from one turn to the next,

The potentiometer shown in Fig. 1 consists of 60 are larger than those in accordance with the potentiometer of a cylindrical body 1 of insulating material, the invention at the center tap of the secondary occur with an evenly distributed winding 2 from winding 3 5. This has been the case with the potentio resistance wire is wrapped. In the drawing meter according to the invention increased accuracy are the distances between the individual turns of the output voltage as a function of the wiper winding For the sake of clarity, shown larger, resulting in 65 position.

than corresponds to the actual circumstances. In the induction shown in Figs. 2 to 4

In parallel with the winding 2, the primary winding 3 P tiven potentiometer arrangement is a rod-shaped

a transformer 3 switched. The input chip body 21, which is made of a material of high performance

5 6

meability consists, evenly with the winding current flow from one of the output terminals OT cut 22 from a wire of proportionately through the winding 23 S, the effective parts of good conductivity, e.g. a copper wire, winding22, which winds shown as resistors35. The sections of the turns 22 are transition points, the winding 28 and the opposing sides insulated and each consist of 5 stands 30 and 31, it is clear that the number of turns in FIG. 4 is the same. A potentiometer shown in FIG. 4, essentially a transformer 23, has a primary winding which has a plurality of adjustable portions 23 P, to which the input voltage VI is applied, which are moved together when is, and one Secondary winding 23 S, which is provided with tapping the winding 28 on the winding 22 shifted fungen24, the number of which is io by one.

is less than the number of sections of the winding Because in the winding 28, through transformer we-

treatment 22. One end of the winding 23 S and each of its kung of the winding 27, an electromotive force taps 24 are each generated individually with the S , the voltage drop per length of the beginnings of the various sections along the winding 28 is the same or connected almost identically to the winding 22. The other end of the 15 the voltage drop per unit length along the winding 23 S is connected to one of the two output winding 22, the winding 28 acts on the terminal OT . The bridged part of the winding 22 denoted by F practically not ends of the individual sections of the winding 22 as a shunt.

stay free. When using the potentiometer, it migrates

The winding 22, which is divided into sections, is surrounded by ao the displacement of the housing 25 on the rod of a jacket-shaped housing 25, which is shorter in the shaped body 21 of each of the contacts represented by one turn of the winding 22 as viewed through resistors 35 in the axial direction of the body 21 and so only part of the length 22 to the adjacent turn, so that the Kondieser wraps winding. The housing 25 has a step-by-step change in its potential, as can be seen from FIG. 3 shows a 25 drives in longitudinal section. As a result, the currents flowing through the various approximately rectangular cross-sections in which two coaxial resistors 35 and the sections of the winding 22 are arranged, windings 27 and 28, are changed, but the winding 28 thereby lies within the winding 27. Caused change in output voltage VO at These windings extend over a length, the output terminals OT smaller than the span, which is greater than that of a section of the 30 voltage change, which is divided by re-cuts at the individual winding 23 contacts shown occurs, outer winding 27 are to the ends of a white

tere secondary winding 23 T of the transformer 23 meters according to the second subject of the invention. The ends of the winding 28 are each, but the connection between the windings 28 and 22 can be capacitive via resistors 30 and 31, respectively. For example, the two output terminals OT connected. opposite surfaces of the wind

When using the in F i g. 2 to 4 show the windings 28 and 22, as described above, The potentiometer set will be stripped by the magneti, but with the exposed surfaces see the flux flowing through the magnetically conductive material with a suitable dielectric material, housing25, the magnetically conductive rod-shaped 40, for example, lacquer or plastic, are coated. Body 21 and the between these parts can also be used to produce the windings 28 and dene air gap runs, the windings 27 and 28 22 aluminum wire are used, the connected to one another as transformer windings, dielectric by anodic oxidation of the upper surface the live outer winding is made surfaces of the windings. 27 in the inner winding 28 generates a current. 45 In the case of a capacitive connection, the inner The number of turns of the winding 28 differs slightly - winding 28 in effect a large number of concomitant on the number of turns of the clocked high impedance bridged by it with the bridged win part of the turn 22, which is divided into sections, fertilize the sub- and is preferably slightly larger. The resistors shared winding 22.

and 31 are dimensioned so that the voltage drop 50 In a further embodiment, the in case in volts per unit length in the windings 28 shown in FIGS. 2 and 4, the inner winding 28 and 22 is the same. fall away, and the multitude of equidistant

In the example shown, there is a touching contact between the winding The same spacing, opposing sections of the windings located contacts between corresponding elongated 28 and 22 are stripped and directly selected turns of the winding 27 and the wine: nander slide. In this way, the winding 22 is replaced between the fertilizers. As in the hand-bridged turns of the winding 22 and the examples described in FIGS Fig. 4 is shown schematically by resistors 35.dar- the voltage drop per unit length of the winding. set 22. The second of the output terminals between the output terminals OT OT occurring would in this embodiment of a trend output voltage VO depends on the effective center tap 65 of the winding 27 connected seeds of the transformer turns ratio that is used to.

of the winding 23 P and the effective part. In the embodiments mentioned, the

the winding 23 S is formed. When following the turns of the windings helically up

7 8

Wound body of cylindrical cross-section. To can be carried away so that between the

However, other strips 73 of the plate 72 and the strips 63 of the

Winding types and differently shaped winding body plate 62 an air gap of 0.127 mm remains,

usable by. The strips 63 are connected to the taps 55 or the

Output voltage required relative movement 5 ends of winding 53 of transformer 54

between relatively movable contact or coupling ties, so that a gradual increase in the potential

treatment parts are effected, while the abutments along the successively arranged

stationary or induction windings remain stationary. Plates 62 is present. It is obvious that

In the case of the FIGS. 5 to 7 shown execution if a tolerable number of

Approximate form finds a relative movement of the winding ίο taps 55 and strips 63 are used

lungs against each other do not take place. should, the successively arranged plates 62

The variable connection is made by a potentiometer of very coarse gradation, positive coupling elements, as shown above in an example of the gradation through the width of the strips in FIG. 2 to 4 described embodiment is limited. The strips 73 of the movable plate 72 are shown for example. The input alternating voltage 15 are each connected to taps 58 or the ends of the voltage VI is connected to terminals 51, 52, winding 57 is connected to S of the transformer 57,
which in turn are connected to the ends of winding 53 of a toroidal core transformer 54. This is chosen so that the average potential-down transformer 54 has a plurality of taps 55 arranged in the same gradation along the plate 72, essentially evenly spaced, and is that of the opposite part of the plate 62. is the one in FIG. 1, winding 2 is the same. One of the two output terminals OT is marked with the tig. The primary input terminal 52 is also connected to the terminals 51, 52, while the other primary winding 57 P of a second toroidal core transformer is connected to a specific tap 58 of the secondary transformer 57, this transformer winding 57 S of the transformer being connected. gate 57 has an isolated secondary winding 57 S , as which tap 58 is selected depends on which has a large number of taps 58 arranged at a uniform distance and in which position of plate 72 relative to one another. These plates 62 the output voltage 0 can be achieved in transformer 57 corresponds to the transformer 3 in should. In Fig. 5 that tap 58 is selected, Fig. 1. The desired capacitive coupling between which is connected to the last of the strips 73, see the taps 55 and 58 through the in 30 that when the plates 72 and 62 against each other the arrangement shown in Figs. 6 and 7 causes. 7 assume the position shown in FIG. If it is desired, each disc, as apparent from Fig. 6 hervor- a second output terminal are provided 75, goes, there is a connected to a center tap of the winding 57 S verisolierten material from an elongated flat plate, such as glass or Bake - 35 is bound.

Ht, on which metal strip 63 is attached to one side It is useful to show at this point

are. These strips extend across the like that in Figs. 5 to 7 shown potentiometers

Plate 62 and are close together in the longitudinal direction, if only the one with one of the

As seen from the direction of the plate, strips 73 connected to the input terminals OT are uniformly spaced

orderly. The strips 12.44 mm 40 would be expedient. If this stripe compared to the stripes

wide and spaced 12.69 mm apart, if 63 were narrow, the output voltage would be

so that there is a gap 64 between adjacent strips as a function of the movement of the plate 72

with a width of 0.25 mm remains. The stripes rise moderately and only in a very rough approximation

extend with one of their ends over the edge correspond to a linear function. If this

the plate 62 addition and are - as shown - would be formed over 45 strips so that its width with the

the edge bent so that it would be comparable to the connection pieces 63 A width of the strips 63, the

form. The strips 63 can be on the plate with output voltage as a function of that from the plate

Attached with the help of a suitable adhesive, not stepping to the same extent as the distance covered.

Screws or bolts fastened or by photo-shaped increase as in the first-mentioned case, but

Etching of a metallic 50 located on the plate run more smoothly, since the strip 73 is variable

Coating are generated. Capacitance between adjacent strips 63 act

The in F i g. The arrangement shown in FIG. 7 has more than one. However, the output voltage would not be

Prepare such plates 62 which approach linearly from end to end. This is due to the effect of the column between

ordered and on a suitable not shown see adjacent strip 63 and for changes

Holding piece are attached. A movable plate 72 55 of the effective distance between each

is to be traced back to strip 73 and strip 63 in a manner similar to strip plate 62. the

73 (cf.Fig. 5), whereby the deviations occurring in the distance would, however, be normal-

the strip 73 is smaller than that of the strip 63. wise regularly during the movement of the strip 73

For example, over a length of 254 mm over each of the strips 63 can repeat

in the case of the plate 62, twenty strips 63, on the same 60 Through the vernier arrangement of the strips 63 and

The length of the plate 72, on the other hand, is twenty-two 73 and the way in which the strips are connected

Strip 73 be arranged. The purpose of this sub- is to improve the effect of the potentiometer,

The difference in the spacing of the strips is the generation. Each strip 73 is used as an independent tap

a vernier effect, as will be explained below. of the potentiometer formed from the strips 63

The strips 73 have connecting pieces 73 A. The 65 is understood. Due to the variable capacities between

Movable plate 72 is secured by suitable strips 63 and 73, not shown, at each strip.

provided guide devices held so that they fen an interpolation instead,

across the successively arranged plates 62 When the tension between the two outer

for example, as described above, twenty strips 63 z. B. 10 volts, then would the voltage in the described embodiment with 22 strips 73 ideally 1 / 2.2 volts per Stripes amount. In fact, some have the Strip 73 higher voltages and other lower voltages, indicating non-linearity of the effective variable formed between each strip 73 and the two closest strips 63 Condenser is due. The transformer winding 57 5 is designed so that they provides an electromotive force of 10 volts, and has taps 58 at intervals of 1 / 2.2 volts. As described above, these taps are consecutive connected to the strips 73. There is thus a direct one through the winding 575 Connection between all of the strips 73, which are at the same time the strips at the intended potential differences holds. There is a connection between the strips 73 as a result of the transformer effect low impedance, so that those strips 73 that have a high positive deviation from the intended Have potential, through the transformer winding 57 5 deliver current to those strips 73 which have a high negative deviation. The high external impedance formed by strips 63 and 73 variable capacitors has the consequence that strips with large positive deviation through Stripes with a large negative deviation are compensated for.

In this way, the effect of the deviations on the interpolation of the voltages that prevail between the individual strips attached to the fixed plate, very largely reduced.

In the example shown in FIG. 5, one of the output terminals OT is connected to the lowermost strip 63. If this connection is removed and a connection is made with another of the strips 63, the output terminal concerned receives the voltage of this strip 63, so that the voltage prevailing between the output terminals OT receives its zero value at another predetermined position of the plate 72.

In the case of the objects of the invention shown in FIGS. 1 and 2 to 4, a potentiometer was used Referred to as they are normally used to achieve high resolution. It However, it has been found that the interpolation effect achieved by potentiometer circuits according to of the invention is so good that a circuit simplification through the use of such Potentiometer is possible, such as. B. the potentiometer according to the third subject matter of the invention, would normally result in a relatively coarse resolution.

In the above-described exemplary embodiments of the three subjects of the invention, one was linear Relative movement used between the movable potentiometer parts. However, it is straightforward possible, under certain circumstances also particularly expedient, the potentiometer parts that can move relative to one another to be arranged in a circle and to effect the relative displacement by rotating one of these parts. For this purpose, for example, the one shown in FIGS. 5 to 7 shown arrangement are modified so that the strips are shaped like a sector of a circle and are arranged on a circle.

Claims (3)

Patent claims: 1. Linear AC potentiometer with one connected to the input voltage Voltage divider consisting of a winding wound on a cylindrical insulating body with several taps that cannot be spaced apart from one another and from one grinder exists, which has several customer contacts that are unchangeable in relation to one another interact with the taps of the voltage divider and those with one of the input voltage derived voltage are coupled so that between the two outer pickup contacts in terms of size and phase the same voltage as between the one bridged by these two pickup contacts Part of the voltage divider winding, thereby characterized in that the voltage divider winding consists of a low-induction, resistance wire wound winding consists that the voltage derived from the input voltage through a separate transformer (3) it is obtained that the number of customer contacts (7) is greater than two, that the customer contacts (7) via a corresponding number of resistors (6) with a corresponding number of connections (5) of the secondary winding (3 5) of the transformer (3) are galvanically connected that the variable potential delivering output terminal formed by the center tap (9) of the secondary winding (3 5) and that, according to the vernier principle, the mechanical distance between the contact points the taps (7) of the voltage divider winding (2) is slightly larger or smaller than the distance between the customer contacts (7). 2. Linear AC potentiometer with one connected to the input voltage Voltage divider consisting of a winding wound on a cylindrical insulating body with several taps that cannot be spaced apart from one another and from one grinder exists, which has several customer contacts that are unchangeable in relation to one another interact with the taps of the voltage divider and those with one of the input voltage derived voltage are coupled so that between the two outer pickup contacts in terms of size and phase the same voltage as between the one bridged by these two pickup contacts Part of the voltage divider winding, characterized in that the voltage divider winding as a transformer winding (22) with several juxtaposed, mutually insulated Partial windings are formed on a workpiece (21) with high magnetic permeability are wound that the voltage derived from the input voltage through a separate Transformer (23) is obtained, whose primary winding (23P) at the input voltage (F /) and its secondary winding (23 5) has several taps that form the partial windings the voltage divider winding (22) feed, and its tertiary winding (23 Γ) with the Primary winding (27) of a further transformer (21,25) is connected, which consists of a the voltage divider winding (22) displaceable sleeve (25) representing the wiper is made of a highly permeable material and a secondary winding (28) which has stripped parts on the windings, which form the inductively coupled consumer contacts, these stripped parts in direct contact with the partial windings of the voltage divider winding (22) so that there is a conductive connection between the voltage divider winding (22) and the secondary winding (28) that the output terminal (VO) supplying the variable potential through the connection point of two resistors (30, 31) is formed, which are connected to the ends of the secondary winding (28), and that a vernier effect is achieved in that the number of turns of the secondary winding (28) is slightly different from the number of turns of the part of the windings of the voltage divider winding bridged by it ( 22) differs. 3.Linear alternating current potentiometer with a voltage divider connected to the input voltage, which consists of a winding wound on a cylindrical insulating body with several taps that are not variable in relation to one another and of a wiper which has several consumer contacts which are not variable in relation to one another and which interact with the taps of the voltage divider and which with a voltage derived from the input voltage are coupled in such a way that the voltage between the two outer pickup contacts is the same in terms of size and phase as between the part of the voltage divider winding bridged by these two pickup contacts, characterized in that the voltage divider winding consists of a toroidal-core transformer (53), that the voltage derived from the input voltage is obtained by a separate toroidal transformer (57) whose primary winding (57P) is connected to the input voltage (VI) and whose secondary winding development has several taps (58) which are capacitively connected to the corresponding taps (55) of the voltage divider forming the toroidal core transformer (53) in such a way that the taps (55) are connected to a corresponding number of non-spaced conductive strips (63) , which are arranged on a base plate (62) made of insulating material, and that the taps (58) are connected to a corresponding number of non-spaced strips (73) which are movable on a second, opposite the first base plate (62) and in this way the slider representing insulating plate (72) are arranged that the output terminal supplying the variable potential is connected to a corresponding tap (58) of the secondary winding (57 5) of the toroidal transformer depending on the desired position of the output voltage zero point and that a vernier setting effect is achieved by the Distance between the strips (73) on the movable Isolierpl atte (72) is less than that of the strips (63) on the base plate (62). 1 sheet of drawings