NO122581B - - Google Patents

Description

Apparatus comprising a converter for converting a tuning signal appearing in electrical form on a single of a plurality of input conductors to a binary signal appearing in electrical form on a plurality of output conductors.

The present invention relates to a system and an apparatus for instructing or reproducing the listening habits or viewing habits of users of television or radio signal receivers. More particularly, the present invention relates to an improved apparatus for converting a decimal representation of the frequency channels to which a wave signal receiver can be tuned, into a binary representation. The present invention is an improvement of the arrangement set forth in US patent no. 2,658,963.

It has been accepted for many years that a method based on instruments to determine the listening and viewing habits of users that receivers for radio waves is the only accurate way to obtain data on this. Such instrumented methods generally make use of a recording device which cooperates with a receiver in each employee's home to indicate, as a function of time, the transmitter stations to which the registered or controlled receiver is tuned for receiving signals, whereupon this registered material is made available to an analysis organization or a research organization in order to transfer it into useful data with regard to the effectiveness of radio and television advertising etc. 1. The employees' homes are selected on a nationwide basis or another geographical basis so that they are truly representative of the radio and television user circles in the relevant area. If the area being studied is the entire United States, then the employees' homes will be spread over the entire United States. Furthermore, these will be selected so that they are truly representative of the listeners or viewers in the considered geographical area.

Prior to the above-mentioned US patent, the recording carried out by such instruments indicated methods, results on a suitable recording medium such as a tape or the like, and the various stations were indicated by the location of the indications across the tape, these indications being representative of the particular vote at certain times, the time being indicated along the length of the tape. Unfortunately, the marking of registration results in a recording device where the position across the band is representative of the tuning conditions does not provide the most efficient route to automatic processing, when it comes to transferring the data reproduced by the recording device to other data that can used in the final statistical analysis. In the above-mentioned patent document, an arrangement is presented in which the registered information before registration was converted from the relevant polling channel's decimal representation, which was taken in by the receiver, into a binary representation that was much better suited for rapid reading or decoding and made it possible to deliver the registered information directly to an electronic number calculator or a similar device. It would be desirable to provide an improved apparatus compared to that shown in the above-mentioned patent document.

The number of homes with more than one recipient has increased dramatically in recent years. While the number of J homes that had more than one recipient j a few years ago was relatively small, today the number of homes that have two or more recipients is very high. In order to get an accurate picture of the listening and viewing habits of users of wave signal receivers, it is obviously important to provide a simple arrangement to reproduce the listening and viewing habits of all receivers in the homes that are selected as representative of the listening circle. A system that is in extensive commercial use today to speed up the process of getting the information about listening and viewing and transferring it into usable data for radio announcers etc. 1., includes a system of registration magazines that can be sent in the mail to the employees' home, where a person in the employee's home replaces the magazine in which the registration for a predetermined period is recorded, with a new magazine sent, so that the material recorded in a subsequent period can be collected on this in due course. This system of having the employee mail the magazines back to the analysis organization and replace the magazines at periodic intervals has proven to be very satisfactory and has greatly reduced the costs of obtaining the necessary registered information. It is very important that the information from a special, monitored recipient is known at all times. It will be understandable that in a home with several recipients, where a co-worker has to process separate magazines for each recipient, there will be a possibility that the magazines will be mixed up, whereby the correct information will not be put in connection with the right recipient. It would therefore be desirable to provide an arrangement by which all registered information from a majority of recipients in a home with several recipients can be registered on a single registration device and properly marked on this, thereby avoiding all confusion that may arise from incorrect placement of the magazines in the devices. Such an arrangement requires that the information from several receivers which may be placed in widely separated places in the home (receivers are generally placed in the living room, kitchen and various bedrooms) can be transferred to a common registration point. It is obvious that the information to be registered could be transferred to such a common registration point with the help of electrical cables or the like, but numerous problems arise when this is done. The same applies if the information is transmitted over a radio connection. It has been found most satisfactory and most economical to send the information from the receiver to the recording device via wires whose sole function is to transmit this information. It is clear that if the information about the tuning state of a receiver which can be tuned to a large number of different channels is to be transmitted to a recording station by means of wires in a home, then the arrangement will be the more satisfactory the fewer and thinner the wires are, and the lower voltage these wires have. It would be desirable to create such an arrangement in which the information can be transmitted to a common place over relatively few wires, even if many polling channels are included, and so that the wires form a circuit free from the risk of fire and electric shock.

In the above-mentioned patent, a code commutator switch was assumed which transferred the polling channels' decimal representation to binary form. This type violates the requirement that a plurality of selector arms in certain cases simultaneously terminate and break certain circuits to form the correct binary code signal. Unfortunately, near the limits of the bandwidth for special stations, it was possible to introduce an ambiguity due to the great difficulty of

to make the points for breaking several contacts simultaneously coincide. If e.g. a receiver was tuned to channel 15 near the edge of the bandwidth for that channel, then the converter from decimal to binary production could actually provide a signal for a station other than station 15. With mechanical links, the problem of "click noise" also occurs in the receiver. It would therefore be desirable to create a decimal-to-binary converter that could eliminate this ambiguity. Accordingly, it is an object of this invention to provide a new and improved decimal-to-binary converter: It is further the object of this invention in a system for recording the tuning state of signal receivers in homes with multiple receivers, to make a power circuit with high impedance and low power which is relatively free from the risk of electric shock or fire.

It is further the object of this invention to provide an improved decimal-to-binary converter which does not include any moving parts, and which can be used in a system for recording listening and viewing habits of all receivers in a multi-receiver home, with a minimal the number of wires connecting the receivers and the recording apparatus in such a home.

Further advantages and advantages of the present invention will appear in the following presentation, and the new features that characterize the invention will be more closely emphasized in the claims which are linked to and form part of this presentation.

For a better understanding of the present invention, reference is made to the accompanying drawings, in which: Fig. 1 schematically shows a system for recording listening and viewing habits in a home with several receivers according to the present invention. Fig. 2a and 2b show schematically and in greater detail parts of the system in fig.

1 to illustrate the present invention, and

fig. 3a, 3b and 3c are diagrams to help you better understand the present invention.

It will be apparent from the following description that certain features of the present invention can be transferred to certain general applications, but they are particularly applicable to systems and devices for determining the listening or viewing habits of people who have radio or television sets. In order to fully clarify the present invention, it has been illustrated as applied to a particular type of system, and further to a system where a majority of receivers are placed in a single home, all receivers having to be controlled. The present invention performs at its best under these latter conditions, and consequently special attention has been paid to this application, although it is obvious that the invention can be used in other systems.

We refer to fig. 1 in the drawings, where a system incorporating the present invention is illustrated for recording the voting status of a majority of receivers who are assumed to be present in a single house, although they may also be in several homes that are close to each other. These receivers are denoted by reference numbers 10 and 11 in fig. 1. It is clear that many more receivers would be involved if several receivers were introduced into a home where the listening or viewing habits are to be determined. The receivers 10 and 11 are schematically illustrated in the block core, each of which is provided with the common antenna 12, and the receivers are provided with the usual means of tuning them to receive the carriers from a plurality of

;enders within the area that the receivers leak. The receivers can be radio receivers, television receivers, FM receivers, or a combination of one or more of these types of receivers. Hitherto surveys have mainly been interested in listening to broadcast programmes, including \M or FM, or television listening, and in general separate surveys are made for audio radio and television listening. Meanwhile, there is no reason, as far as the present invention is concerned, that a registration of the voting title of a majority of recipients, regardless of their type, cannot be carried out with a single element for recording the signals.

As illustrated, each receiver such as 10 and 11 is connected by a suitable mechanical link as 13 to an accessory to the receiver denoted by 14. Since these accessories to the receivers are identical, the same reference number is used for each of them. Each receiver accessory includes a position switch indicated by the block diagram of FIG. 1 and denoted by 15. The receiver accessory also includes a decimal-to-binary converter belonging to the present invention, and in the drawing indicated by reference number 16. It is assumed that each receiver accessory 14 will be closely connected to a special receiver such as 10 and 11, considering the fact that the mechanical link 13 should be relatively short. In reality, this mechanical link may be a flexible cable, a pulley device or the like, and therefore each receiver accessory should be close to its receiver. Furthermore, the accessory is a relatively small device that can be built into many radio cabinets so that the employee will not even be aware of its existence.

In order to record on a single recording element the information about the channels to which the receivers 10 and 11 are tuned, each of the receiver accessories 14 is connected with a suitable cable 17 to a recording device which is generally referred to under 20. This recording device is schematically indicated in fig. 1, and in certain respects really identical to the recording apparatus described and protected in the above-mentioned patent document. This recording apparatus includes, among other things, a contact sensor 21, a system for advancing film 22, a thyratron amplifier 23 which controls a signal lamp 24 connected to the system for advancing film 22, which signal lamp's light is controlled by an aperture or shutter disc 25,

l

In all cases, the tuning state of the receivers 10 and 11, and any others to be registered in a particular home, is represented by electrical signals produced by means including the position switches 15. Furthermore, the decimal representations of these electrical signals by means of decimal-to - the binary space formers be converted into binary indications which are suitably recorded by the recording apparatus 20. It is understood that the recording apparatus 20 in the present invention is preferably similar to that found in the aforementioned patent document, including a suitable magazine which is suitable for being sent by post , in which the registered information is collected. Since the registered information from several recipients is contained on a single tape in a single mailable magazine, there can be no problems with the employee making mistakes, since the analysis organization only sends him a single magazine. No description of the dispatchable magazine is given here, as this is fully described in previous patents, and whether a dispatchable magazine is included or not is of no importance, except that it solves a problem created by the necessity to use such mail-only magazines.

With reference to fig. 2a and 2b of the drawings, which together show in more detail the system first shown by the block diagram in fig. 1, it will be noted that the same reference numbers are used to characterize the corresponding parts. In fig. 2a, the receiver 10 is produced, which can be of any receiver type, whether the transmitter signal is amplitude-modulated, frequency-modulated or both, or whether the signals are optionally transmitted in visible or audible form, or both. As illustrated in fig. 2a, it is schematically indicated that the receiver 10 includes an antenna 12 and a circuit between the antenna and ground 27. In addition to this, it is illustrated as comprising a signal reproducer 28, which is schematically illustrated as a speaker, although it visually could also mean a fluorescent screen or similar device. Inserted into the antenna circuit which comprises the antenna 12 and the ground connection 27, and the signal receiver 28, one naturally finds the usual parts of a receiver which are not shown, but which may include a tunable radio frequency amplifier, a mixer or modulator, and in the case of a ordinary audio radio receiver, an audio frequency amplifier, etc. 1. Since the receiver 10 is representative of any ordinary receiver, whether it is an audio radio receiver or a television receiver, its operation will be readily apparent to those skilled in the art, and consequently no further explanation will if this is included in the following description.

The receivers generally include some form of voting apparatus, and for the receiver 10 this is schematically denoted by the reference number 30 in fig. 2a, which comprises a setting button 31 and a device 32 for varying the resonance frequency. The button 31 and the device 32 are rotatably connected to each other via a setting shaft 33. The receiver 10 also includes a power supply, schematically indicated by the reference number 34, which power supply is suitably connected to an outlet on an ordinary wire 35, which has an ordinary plug at the end connector 36. The power supply to the receiver is controlled in the usual way through a fixed switch or an "on-off" switch 38. In a normal receiver, this switch is usually connected to the device for volume control.

For transmitting power to the receiver accessory 14, there is a pair of power supply lines 39 leading from the high-current circuit 34 of the receiver 10 to the receiver accessory 14. To ensure that the recording apparatus 20 is connected to the receiver 10, then that all use of the receiver is indicated at all times, one wire of the cable 35 is conductive only if the plug connection 40 connects the recording apparatus 20 to the receiver accessory 14. This connection 40 is illustrated as a multi-plug connection, two plugs of which connect the conductors 41a and 41b to complete the high current connection to the power supply equipment 34 on the receiver 10. This is a move to ensure that the receiver 10 can work. It is obvious that with the arrangement shown in fig. 2a, no current can flow into the wires 39 when the connection 40 is broken, even if the fixed switch 38 is engaged.

It is understandable to all professionals that from the receiver 10 or any receiver that is under control or monitoring, one or the other output or information indicating the voting state of the receiver must be obtained. This information can be of an electrical or mechanical nature. It is understood that if the receiver under control is a super-heterodyne receiver, then the output signal from the local oscillator will vary in frequency with changes in tuning, so that this will give an indication of the receiver's tuning state. This can be called information of an electrical nature. Likewise, the position of the device 32 to vary the resonance frequency is clearly characteristic of the receiver's tuning state, and such a variation of the tuning shaft's position could be called mechanical information to indicate the receiver's tuning state in a similar way to the electrical information obtained when measuring the frequency in a local oscillator. In the present invention, it is clear that both forms of information can be used, but to illustrate the invention, the drawings show an arrangement that makes use of the mechanical information.

In order to convert the voting position of the voting shaft 33 in the receiver into an easily transmittable information such as an electrical signal, a position switch 15 is placed in the receiver accessory 14. This position switch can be of the type described and claimed to be protected in US patent no. 2,658 963. In its basic features, the position switch 15 comprises a rotatable, conducting shaft 43 to which is attached a plurality of evenly spaced cam discs 44a, 44b, 44c, 44d, 44e, 44f, 44g, 44h, 44i, 44j, 44k, 44m, 44n, 44p and 44q. As illustrated, there are fifteen cam discs 44. Each of these cam discs 44 has an identical raised portion to make contact with a corresponding contact 45, indicated by the same designations as the cam discs 44. Thus, upon a certain rotation of the cam disc 44a, a predetermined point of this comes into contact with the associated contact 45a. In the same way, the cam disc 44b will at a certain point during its rotation come into contact with its associated contact 45b, and thus further with the rest of the cam discs 44 and the associated contacts 45.

The cam discs 44 are preferably adjustable in relation to the shaft 43, so that they can interact with their associated contacts 45 in any predetermined order. In the same way, the position switch 15 should include the features described in US patent no. 2,484,734, whereby each cam disc 44 will influence its associated contact 45 over the entire position of the tuning shaft 33 where a particular transmitter can be received. It will be understood that the angle over which this can happen will vary, depending on which station applies, as described in the aforementioned US

patent no. 2 484 734. Although 15 cam discs 44 have been produced, all associated with the

same shaft 43, which would be capable of providing indication from fifteen individual tuning channels, it is readily apparent that more or fewer cams may be used, and indeed some of the cams may be used to indicate tuning on a frequency modulation band, while others could be used to indicate the tuning of an amplitude modulation band. Fifteen cams have been found to be fully sufficient to cover the ordinary listening that takes place with a particular radio receiver, since there are usually not that many stations that can be received satisfactorily or at least are not usually tuned to. In the case of television sets, there is currently a maximum of seven channels available on a receiver. It will be understood that the fifteen channels covered by the position switch are only representative and allow illustration of the present invention's decimal-to-binary converter to convert the fifteen decimal values into a relatively small number of binary values. It is obvious that the cam disks 44 will be placed on the leading shaft 43 in such a way that the associated contacts 45 are affected in the order in which the tuning shaft 33 is brought to scan the frequency spectrum on the receiver 10.

In order that the position of shaft 43 on the position switch 15 can be brought into accordance with the tuning shaft 33, a suitable mechanical link is provided which has been referred to up to now with the number 13 and which is specifically described as a pair of Bowden cables 47, if ends are preferably wound around the respective shafts 33 and 43, or around suitable pulleys, such as 48 and 49 connected to these shafts. As illustrated, the pulley 48 is mounted on the shaft 33, while the pulley 49 is drivingly connected to the position switch shaft 43 through a pair of gears 50 and 51. From the above description, it will be clear that the cam discs 44 can be adapted individually so that they form an electrical circuit with an associated contact 45 as soon as the tuning shaft 33 is tuned to a specific transmitter station, which the relevant cam disc 44 represents.

As previously mentioned, power is supplied to the receiver accessory 14 through the wires 39, and this occurs every time the fixed switch 38 is closed, and of course, provided that the connection 40 is engaged. The wires 39 are connected to the primary windings 53 of a voltage-increasing transformer 54

5

which has a secondary winding 55. The transformer 54 was, in a particular embodiment comprising the present invention, a step-up transformer which increased the normal mains voltage to 255 volts, which voltage was found desirable for the decimal-to-binary converter 16 to be described in detail in the following. This transformer 54 serves as an isolating transformer to isolate the supply line 35 from the rest of the receiver accessories and recording device, especially the cable 17, thereby eliminating the risk of electric shock. This transformer is so constructed that even with a short circuit across it there is no risk of fire. One end of the secondary winding 55 is illustrated as being connected to the position switch's conductive shaft 43 through a noise damper 56 and a collector ring 57, which is integrally connected to a brush-like element 58. The other end of the secondary winding 55 is connected through a wire 60 with the decimal-to-binary converter 16 which will be described in the following. Appropriate noise suppressor capacitors 61, 62 and 63 are also connected to the transformer 54 in the usual manner. In order to produce a detectable output every time the receiver 10 is switched on, a voltage divider comprising the resistance elements 64 and 65 is placed, connected across the secondary winding 55 of the transformer 54. A potential is transferred from this voltage divider to a line 67 which together with the line 68 , connected to the line 60, is included in the cable 17 which leads to the recording device 20 and which will be described in more detail in the following. The wire 67 connected to the voltage divider described above produces on the recording apparatus an indication "on" for a radio or signal receiver each time the receiver is turned on, even if the receiver is not tuned to any station covered by any of the cam discs 44.

The decimal-to-binary converter 16 is in FIG. 2a particularly illustrated as an apparatus for transferring a decimal representation based on 15 wires to a binary representation based on four wires. It will be apparent from the following description that the binary arrangement with four wires and the decimal arrangement with 15 wires is an example to illustrate the present invention and is not intended as a limitation. Generally speaking, the decimal-to-binary converter described here comprises fifteen separate wires on the input side representing the decimal side, and four wires on the output side representing the binary side. When voltage is applied to any of the fifteen input lines, a single combination of potentials is produced on the four output lines. The voltages on the output wires are classified into two groups: Those which are termed "unwanted", which are below some maximum value, and those which are termed "wanted", and which are at least three times greater than the said maximum value. There are fifteen different combinations or permutations of desired and unwanted voltages. Thus, if a potential is applied to any of the fifteen input lines, there is only one combination of voltages on the output side to identify which input line was energized.

The means of achieving these individual combinations are as follows: An ordered system of fifteen different desired and undesired combinations is arranged on the four output lines. Each such combination is identified by a special input line. Between each input wire and any of the output wires that must have a desired voltage, a resistor R is connected. Between each output wire and earth or a common wire, resistor "r" is connected, which has a value equal to R/10. It will be noted that a desired voltage is obtained on an output line when a resistance R is connected directly between this line and the input line that is energized, and that an unwanted voltage is obtained at the output line for the simple reason that there are only indirect paths between the output line with unwanted voltage and the input line which has been energized, as these paths include several resistors R in series-parallel combination.

Referring in particular to fig. 2a comprises the decimal-to-binary converter et

grid of fifteen input wires 70

specifically designated as 70a, 70b, 70c, 70d, 70e, 70f, 70g, 70h, 70i, 70j, 70k, 70m, 70n, 70o, 70p, 70q. These decimal numbered lines 70 are illustrated in fig. 2a in that the wires determine the horizontal part of the grid and carry code numbers respectively "1", "2", "3",

"4", "5", "6", "7", "8", "9", "10", "11",

"12", "13", "14", "15". In addition to this is

where the binary digit or output lines 71, specifically designated as 71a, 71b, 71c, 71d, which are shown as the vertical lines in the grid, there being four of them due to the four output binary system. Wire 71a carries code number "1", wire 5

lb carries code number "2", wire 71c carries code number "4", while wire 71d carries code number "8". It will be clear without further ado that if there is a suitable grouping of these codes, their sum will each give a number from 1 to 15. It will thus appear that if a jittery output voltage is obtained over several combinations of the binary-digit lednin-

gives 71, then one can get a single code for fifteen stations on the four wires. Below is a table of fifteen decimal numbers representing fifteen stations, and the code number(s) for the wires 71 that must be energized, so that the sum of these code numbers is equal to the decimal digit.

In accordance with the present invention, a plurality of passive impedance elements, such as resistive elements, connect the fifteen decimal-digit leads 70 and the four binary-named leads 71. As illustrated, various of the leads 70 are connected to the leads 71 by a plurality of resistors 72, 73, 74,, 75, 76, 77, 78 and 79. Thus, wire 70a is connected to wire 71a through resistor 72. Wire 70c is connected to wire 70a through resistor 72. Wire 70e is connected to wire 70a across resistor 74 etc. For a particular application, resistors 73, 74, 75, 76, 77, 78 and 79 had a resistance value of 680,000 ohms, while resistor 72 was 470,000 ohms. All resistors could have been the same size, namely 680,000 ohms, but a greater spread between desired and unwanted voltages could be obtained if resistor 72, which connected wires 70e and 71a, had a slightly smaller resistance. Likewise, the binary digit wire 71b with code number 2 in accordance with the present invention is connected to various of the decimal digit wires 70 in groups of two through a plurality of resistors 80, 81, 82, 83, 84, 85, 86 and 87. In this arrangement the first wire 70a is not connected to wire 71b, but the next two wires 70b and 70c are connected to the binary digit wire 71b through the resistors 80 and 81. The decimal digit wires 70d and 70e are not connected to the binary digit wire 70b. However, the next two wires 70f and 70g are connected to this through resistors 82 and 83 respectively.

Referring to the foregoing, it will be clear that the binary digit wire 71c, which carries code number "4", will be connected to the wire 70 in groups of four. The first three wires 70a, 70b and 70c are not connected to wire 71c. However, the next group of four wires 70d, 70a, 70f and 70g are connected through resistors 88, 89, 90 and 91 respectively to the binary digit wire 71c. The next group of four decimal-digit wires 70m, 70n, 70p and 70q are connected through resistors 92, 93, 94 and 95 respectively to the binary-digit

wire 71c. Since the binary digit line 7ld carries the code number "8", it is

connected with the decimal-digit wire 70 in groups of 8. For this purpose, the first seven decimal-digit wires 70a, 70b, 70c, 70d, 70e, 70f and 70g are not connected to the binary-digit wire 71d, while in the remaining eight decimal-digit leads ] ger 70h, 70i, 70j, 70k, 70m, 70n, 70p and 70q through the resistors 97, 98, 99, 100, 101, 102, 103 and 104 respectively are connected to the binary digit line 71d. All resistors 81 to 87, connected to the binary digit wire 71b, for a special application had a resistance value of 680,000 ohms, while the resistor 80 connecting the wires 70b and 71b, mutually had a resistance of 470,000 ohms to obtain a greater spread between desired and unwanted voltages. Similarly, for the same application, all resistors 89 to 95, connected to the binary digit wire 71c, had a resistance of 680,000 ohms, while the resistor 88, which connected the wires 70d and 71c to obtain a greater spread of the voltages, had a resistance of 470,000 ohms. All the resistors that have been described so far are of the type R above.

From the above description, it will appear that the decimal-to-binary converter 16 comprises passive linear impedance elements, and that no moving parts are included in it. It is understood that the present invention is not limited to the use of resistors, as illustrated, as capacitors can also be used. They would maintain the same high impedance level and would actually provide greater accuracy than carbon resistors if needed. Furthermore, they would only require an insignificantly larger volume or space. The size of the capacitive reactances would be chosen in such a way that they would produce the desired ratio between the desired and unwanted signal and voltage level, which will be described in more detail in connection with the passive resistance elements mentioned in connection with fig. 3e, 3b and 3c. In fact, inductive reactances could also be used instead of the resistors, but problems would arise due to the inductive couplings between the induction coils, and a much larger volume would be needed to accommodate the device.

To complete the power supply circuit to the grid comprising wires 70 and 71, the end of the secondary winding 55 of transformer 54 which is connected to wire 60 is connected in parallel with each of the binary digit wires 71 through suitable resistors 106, 107, 106

)g 109 which can be called "r" resistors )g which has approximately 1/10 of the resistance value of the R resistors. As illustrated, the notch 106 is inserted between the wire 30 and wire 71a, the resistor 107 between

wires 60 and 71b, resistor 108 between wires 60 and 71c, and resistor 109 are inserted between wires 60 and 71d. Preferably, this wire 60 is grounded as illustrated at 114. Thus, one end of each resistor 106, 107, 108, 109 is grounded, and the other end of these resistors effectively supplies the output potential of the decimal-to-binary converter 16. Accordingly, these output ends of resistors 106 to 109 connected to the recording apparatus 20 through suitable leads in cable 17. As illustrated, the output end of resistor 106 is connected to a lead 110. The output end of resistor 107 is connected to a lead 111. The output end of resistor 108 is connected to lead 112, and the output end of resistor 109 is connected to wire 113. It is clear that whenever one of the cams 44 affects its associated contact 45, an output voltage will occur across either or

all resistors 106 to 109, of course

provided that the transformer 54 is supplied

Energy. As will be apparent from the following description, some of the voltages across the resistors will be higher than others, and some of these voltages will be considered unwanted voltages. It would be desirable to produce zero output voltages across those resistors which should have no potential for a particular code situation, but for practical reasons this is not achievable. However, the ratio between desired and unwanted voltages can be made so high that the unwanted voltage is in reality not essentially different from a zero series.

In the event that a stronger separation between desired and unwanted voltage levels is required, one can increase the ratio of the resistances R from the decimal-to-binary wire to the resistances "r" from the binary wires to ground with a corresponding increase in the supply voltage, so that the desired output voltage will be the same. This can also be done by amplifying the output voltage. Above a ratio of 10 for the resistors, the desired-to-undesired ratio becomes almost linear with the ratio of the resistors.

If the system is extended to any number of binary-digitized outputs with n= number of binary digits, then (2n-l) will be equal to the corresponding number of decimal digits (D) that can be represented in binary form. For example, with two binary digits (N = 2), 22-1 = 3 is the number of decimal digits, etc. as follows:

If one were interested in using the absence of an output signal as an indication, the decimal digits D in the above table could actually be increased by one in each case. However, in the illustrated application it is desired to use the absence of a signal when the receiver 10 is switched on, as an indication of the fact that a channel is set that is not provided for in the recording device 20.

To eliminate unwanted noise and to serve as noise suppressors, suitable capacitors 115, 116, 117, 118 and 119 are included in the decimal-to-binary converter 16. These capacitors are connected between ground and the output leads 67, 110, 111, 112 and 113.

Decimal-to-binary converter func

tion is best understood by reference to figures 3a, 3b and 3c, where a decimal representation based on three wires is illustrated, which can be transferred to a binary representation based on two wires. The corresponding parts of figures 3a, 3b and 3c are indicated by identical reference numbers. With reference to fig. 3, there is illustrated a decimal-to-binary converter in which are placed binary digit wires 120a and 120b illustrated as the vertical wires in the grid and carrying respective code numbers "1" and "2". The decimal numbered wires 121 are specified as 121a, 121b and 121c. As in the arrangement in fig. 2a, the binary digit wire is connected to each of the decimal digit wires 121 by appropriate resistors specified as 122 and 123. As illustrated, wire 212 is connected to wire 120a through resistor 122. Similarly, wire 121c is connected to wire 120a through resistor 123. However, wire 121b is not connected to 120a. Since the binary digit wire 120b carries code number "2", it is connected to wires 121 in groups of two. Thus, wires 121b and 121c are connected to wire 120b at resistors 124 and 125.

Wire 121a is not connected to wire 120b.

To provide power to the decimal-to-binary converter 126 shown in FIG. 3a, 3b and 3c, a potential source 127 is connected to the primary winding 128 of the transformer 129 which has a secondary winding

130. One end of the secondary winding is

connected by a movable switch element

131 and the subsequent ends may selectively

combined with contacts 132a, 132b and

132c, each of which is connected to a corresponding one of the wires 121 which have the same designation. One end of the secondary winding 130 is illustrated as the grounded end which is. connected to the binary lines 120a and 120b through the resistors 134 and 135 respectively. The output ends of the resistors 134 are connected to the output lines 136 and 137 respectively. When the transformer 120 is supplied with energy, different voltages will arise in relation to earth at the ends 136 and 137 These voltages are respectively denoted as V, and V2.

To simplify and facilitate the understanding of the present invention, it is assumed that the voltage across the secondary winding 130 is 110 volts, and that the resistors 122, 123, 124 and 125 are 10 ohm resistors. Further assume that resistors 134 and 135 are one ohm resistors. Fig. 3a shows an arrangement where the switch element is in position for station one, which is decimal number one. Fig. 3b shows the arrangement when station two is active as far as the decimal digit is concerned; and fig. 3c shows the arrangement where decimal digit three is in operation. For the particular circuit parameters mentioned above, the output voltage at end 136 in fig. 3c be nine and a half volts, while the output voltage V2 at the end 137 is 5/10 volts. It will be seen from the table above that a binary signal for station one will appear on wire 1. Since the ratio of the desired signal at wire 136 to the unwanted voltage at wire 137 is nineteen, it will be clear that no problem arises with make the unwanted voltage ineffective. The output voltages can be easily calculated using the fundamental laws for impedance networks. With the same device, the voltages V, and V2 in fig. 3b be y2 volts, respectively 9y2 volts or in other words the reverse of fig. 1, so that the binary signal will only act effectively at the output of line 120b.

In order to produce code number three by the binary representation, it is desirable for station three to have effective output voltages at both lines 120a and 120b, and this can be easily seen from the assembly in fig. 3c that both output voltages and V2 will be 10 volts, and the desired decimal number equal to the sum of the code numbers will therefore be obtained.

It will be understood that the same converter 16 which transfers a decimal explanation can be provided for 15-wire decimal-to-binary representation to a 4-wire binary representation, but the much simpler arrangement shown in FIG. 3a, 3b and 3c, enables a simple explanation of this.

Although in the described arrangements, alternating current voltage is indicated as

supply source, the present invention is equally applicable to direct current. It will be assumed, as mentioned above, that the decimal-to-binary converter in the present invention can be used with other digit combinations than fifteen in the decimal system to four in the binary system, or decimal/three to binary/two. As the capacity of the converter is increased, the spread between desired and unwanted potentials increases, provided that no change is made in the ratio between the resistances "R" and "r". For the arrangement shown in fig. 2a and using the parameters mentioned above, the following table can be drawn up

The numbers in brackets are those that would appear if all resistors R were the same, namely 680,000 ohms. Thus it is shown why the resistors 72, 80, 88 and 97 have been chosen with a resistance of 470,000 ohms. From the above table it will be seen that the output voltage from the decimal-to-binary converter 16 is in the neighborhood of fifteen or sixteen volts, and it is obvious that this low voltage can be transmitted over a low voltage cable, such as 17 having only a few wires, in reality six. This cable can be run along the baseboard in the house or hidden, if desired, without presenting any risk of fire or accident. In fact, the construction has proven that even short-circuiting the ends of the transformer 54 will not produce such high currents that there will be any fire hazard.

In order to record in binary code the output voltages from the decimal to binary converter, the recording apparatus 20 is arranged, which is generally indicated in the block diagram of fig. 1. This recording device 20 includes everything shown in fig. 2b and is also indicated by reference number 20. In principle, this recording device contains a number of elements which are fully described in the above-mentioned US patent no.

2 658 963. As illustrated, this includes

recording apparatus the contactor 21, the film advance system 22, the thyratron amplifier 23, the signal lamp 24, a disc shutter or aperture disc 25, an indicator for a power-free condition 140, a mechanical timer 141, and associated control devices. As fully set forth in the above-mentioned patent document, the medium on which the registration is reproduced is a photographic film,

a small part of which is shown in the film advance system 22 in fig. 2b and referred to with reference number 143. It is understood

that as far as the present invention is concerned, the recording medium 143 need not be a photographic film. However, photographic film lends itself well to rapid decoding and has numerous other advantages, so that in order to illustrate the present invention, a film-like register tape 143 which can be moved over a suitable progress conductor 144 is assumed to be used.

It is assumed that the signal light 24 is placed to expose selected parts of the film 143, and suitable lenses 145 and 146, a disk 157, and a diaphragm 25 are inserted in the beam path between the light source 24 and the film 143. To ensure a long life, the signal light should or the lamp 24 preferably be an argon lamp, in which case there will be connected in series with a suitable current limiting resistor. This lamp 24 will, as will be apparent from the following description, be connected via a suitable circuit to and controlled by the contactor 21 in order to produce the necessary control of the current circuit. When the light is turned on, it will produce a registration mark on the film 143. When using the decimal-to-binary converter of the present invention and described above, with a relatively low output voltage, the voltage will be insufficient to supply enough energy to the lamp 24. Therefore, the thyratron amplifier 23 is inserted to ensure that the low output voltage from the decimal-to-binary fbrmer 16 can appropriately supply the lamp 24 with enough energy at the right time. The lamp 24 is energized at least once a minute and sometimes several times a minute, and in order to avoid impact on the radio, suitable filter devices and noise suppressor circuits are fitted which include the capacitor and resistance elements already described.

In order to cause the lamp 24 to expose certain portions of the film 143 in a predetermined manner, so that binary code indications are generated at the correct location across the register element 143, it is necessary to expose predetermined transverse portions of the film 143 synchronously with the supply of energy to the light source 24. Therefore, the already described optical system is arranged, including the light source 24, of which the diaphragm 25 is a very important part.

In order to bring the diaphragm 25, which is a rotatable element, in line with the contactor 21, both of these are preferably driven at one revolution per minute by means of a suitable motor 160, which, according to the illustration, is directly connected to a common shaft 161 for the rotary arm 162 on the contact sensor 21 and the aperture disc 25. In order to cause the light from the light source 24 to fall at different predetermined locations across the film 143 depending on the impulses induced by the contact sensor 21, the rotating aperture disc 25 is provided with a plurality of long stretched slits or openings 164. These slits 164 are arranged in a spiral around the shutter whereby the light moves successively across the film 143. The slits thus appear in order under the light source 24 so that the film is exposed across, starting from one side and moves across. Preferably, there should be a suitable device to move the film forward a slit width in the aperture disc during the time the disc rotates one revolution, so that the recording will always take place on an unexposed part of the film. The disk 25 is also provided with a large opening 165, so that the controller can see the entire film. In reality, and as will be described below, the lamp 24 is always energized for a predetermined period of time, such as several minutes after power is restored from a power outage. Thus, the openings 164 will expose the entire film surface immediately after a power failure and thus provide a clear registration signal when a power failure has occurred. When initially adjusting the optical system on the recording device in the present invention, the contact sensor 21 must be set so that a particular contact on. this is energized or at least connected to the rotating contact arm 162 when a special slit 164 on the diaphragm 25 is in position to transmit light from the lamp 24 to the film 143.

So that the motor that gives one revolution per minute, power must be supplied continuously as long as there is no power failure, the central station is provided with a power source, not shown, to which the wires 167 can be connected by means of an ordinary socket 168. The wires 167 are connected directly to the motor 160.

The contactor in the present invention is illustrated as a very simple type of switch with a rotating switch arm 162 which is capable of sequentially making contact with a plurality of contacts 169, which are separately indicated as 169a, 169b, 169c, 169d, 169e, 169f, 169g, 169h, 169i, 169j, 169k, 169m, 169n, 169p, 169q, 169r, 169s, 169t, 169u, 169v, 169w, 169x, 169y and 169z. In fact, 24 contacts are drawn, although a larger or smaller number can easily be used. To produce recording of the tuning state for a single receiver, such as 10, only eight contacts 169 are needed, but for each new receiver to be measured and recorded on the same film 143, an additional five contacts are needed. As illustrated, wire 68, included in channel 17, is grounded at the commutator switch, while wire 67 is connected to contact 169d, wire 110

LI

with connector 169e, wire 111 with connector 169f, wire 112 with connector 169g, and wire 113 with connector 169h. If there were more receivers, then wires corresponding to those included in cable 17 should be connected to additional connectors 169 in a manner easily understood by those skilled in the art.

In order to provide power for various purposes in the recording apparatus 20, there is connected to the wires 167 a suitable transformer 170 which has its primary winding connected in parallel with the motor 160. The secondary winding of the transformer 170, referred to under number 172, is a winding with a center tap from which a wire 173 is held at earth potential by means of the earth connection 174. The other ends of the secondary winding 172 are through suitable rectifiers 174a and 175 united to a common connection point 176 which includes the positive rectifier terminal. In fact, the output voltage at point 176 comprises an unfiltered full-wave rectifier voltage from a double rectifier, which can be called a "folded" alternating voltage, and this is decisive for correct operation. Such a "folded" alternating voltage at point 176 is fed to the anode circuit of the thyratron amplifier 23, so that it is of no importance what the phase of the signal from the recording device may be, in other words, so that it is of no importance how the plug is inserted in socket 36. A true DC voltage would eliminate the polarity problem, but there would then be no zero voltage needed to block current flowing through the thyratron amplifier to be described below.

It has been found desirable to place time signal indications on the register medium 143, and so-called minute marks "MM" have been found very useful. For this purpose, one end of the secondary winding 172 of the transformer 170 is, through a suitable voltage-reducing resistor 177 and a wire 178, connected to the contact 169b. Thus, an alternating current potential is continuously transmitted to contact 169b at all times, and once a minute when the rotating contact arm 162 touches contact 169, a potential is present to supply energy to the lamp 24.

It was pointed out above that at the relatively low voltages that can be obtained at the output of the decimal-to-binary converter, a suitable aid in the form of the thyratron amplifier 23 was necessary to provide energy for the lamp 24. The thyratron amplifier is illustrated as comprising 1 shows an electron discharge tube 179, comprising an anode 180, a cathode 181, a control electrode 182, and a screen grid 183. The anode circuit, which includes the anode 180 of the thyratron amplifier 23, is connected through a suitable current limiting resistor 184 and the contacts 185a of a relay 185 with the positive pole 176 of the folded alternating current voltage through the lamp 24. To create a predetermined cathode voltage, the cathode 181 of the electron discharge tube 179 is connected to ground through a suitable fixed resistor 187 and an adjustable resistor 188, and through the series resistors 189 and 190 to the positive terminal 176, the resistors 187, 188, 189 and 190 forming a voltage-distributing network between point 176 o g ground 174. The screen grid 183 is connected to the cathode 181 through a suitable current-limiting resistor 191. The control electrode 132 of the thyratron amplifier 23 is, on the other hand, through a suitable resistor 193, a switch 194 and a resistor 195 connected to the rotating arm of the contactor 21. When the switch 194 is closed, as indicated in fig. 2b, the potential applied to contact 169b, through wire 178, will cause the thyratron 179 to ignite once every minute when the rotating arm 162 touches contact 169b. Resistor 188 is set for proper regulation so that the unwanted voltages from decimal-to-binary converter 16 will not cause thyratron 179 to fire.

Since extensive experiments have shown that power outages occur at least once a month in sixty percent of the homes where receivers are controlled, suitable means must be provided to provide correct time registration. Therefore, a mechanical time marker 141 is provided, as referred to above, which may be identical to the arrangement described and protected in Swedish patent no. 181 480. This mechanical time marker 141 comprises a mechanical clock, of which only the spring 198 is shown in fig. 2b. This mechanical watch includes winding in the form of

an electric motor 199 which is directly connected to the spring 198 through a shaft 200 to pull the spring 198. This pulling motor may be a synchronous motor, although a synchronous motor is obviously unnecessary, since any other motor is satisfactory. As illustrated, traction motor 199 is connected by suitable wiring to power supply lines 167, which also supply motor 160 and transformer 170 with power. As illustrated, 2

the motor 199 continuously pulls the spring 198, and of course a sliding clutch or similar can be inserted to prevent over-pulling. Control devices can be provided for the circuit whereby the motor 199 is connected to the power source for a few minutes every hour to pull the spring 198. Instead of a coupling arrangement, the motor 199 can be of a type that can be braked most of the time without damage and just runs when the spring 198 is sufficiently under-tensioned to permit re-pulling thereof.

To deposit the desired time information controlled by the mechanical clock on the mechanical time marker 141, this clock can advantageously operate three rotary switches: An hour switch designated at 201, a day or 24-hour switch designated 202, and a week or seven-day switch marked 203. The hour switch should preferably be of the type which will allow the switch arm 201 to engage contact 201a most of the time, but momentarily close contact 201b for a short period at the end of each hour. In a similar way, the day switch arm 202 will be connected to contact 202a for most of the day, and for an interval of less than an hour at the end of the day, it will be connected to contact 202b. In the same way, the week switch arm 203 will be connected to a contact 203a for most of the week, but will close the contact 203b for a period of less than a day.

It has been found desirable to provide uniform time information on the recording medium 143, and for this purpose contact 169a, which can be called the time contact, is connected by means of a wire 205 to contacts 202a and 203b on the mechanical time marker 141. Also the switch arm 201 is connected by means of a wire 207 to one end of the resistor 177 to thereby provide power to the switch arms in the mechanical time marker. With this arrangement, it will be clear that at the end of each hour, when the contact arm 201 closes the contact 201b, a potential will be transferred through the wire 205 to the contact 169a whereby the thyratron amplifier 23 will cause the lamp 24 to light up so that it produces the time mark "MM" with a single exception. This exception will occur at the end of each day or after twenty-four hours when the contact arm 202 is closed with the contact 202b. This will break the connection between wire 205 and the power source, and once every 24 hours the hour mark will be looped. This will enable one to look at a record of whether a power cut has taken place, and if so to: discover which part of the day was before and which was after the power cut occurred. It is also desirable to place twenty-four-hour marks on the recording element 143, and for this purpose the contact 202b on the mechanical time marker 141 is connected by means of a wire 209 to the contact 169c on the contact transmitter 21. Thus, at the end of each day, when the hour arm 201 closes contact 201b, and the day arm 202 closes contact 202b, a day mark "MM" is applied to the element receiving the registration during the time when the rotating arm 162 closes contact 169a. However, there will be an exception to this, namely at the end of each week, when the 24-hour mark is eliminated. This is because at the end of the week the week arm 203 will stop contacting 203b. At this time, however, a mark will be placed in the place of the hour mark due to the fact that contact 203b is also connected to wire 205. In this way, a time marking will be produced where a mark is produced every hour except the 24th hour in around the clock, and a twenty-four-hour mark will be produced every day except the seventh day of the week, with a further exception whereby on the seventh day of the week the hour mark is not excluded. This special time information allows one to orient a register strip in its correct time context even if a power failure has occurred, and allows a

to use literally all of the recorded information.

To cope with the conditions in the event of a power failure, a power failure indicator 140 is arranged which only comprises the relay 185, which has normally open contacts 185a and normally closed contacts 185b. The relay 185 is shown so that it receives its energy from the power lines 167, and it is shown in its energy-carrying position with the contacts 185a closed and the contacts 185b open. This relay is a time-delay relay that requires approximately two to three minutes to close its contacts 185a and open its contacts 185b when initially energized. It should ideally be a relay that instantly drops out. The normally closed contacts 185b are connected to a current circuit which short-circuits the lamp 24 directly across the power grid. This can easily be seen in fig. 2b in the drawings, where the end of the current-carrying wire 176 is connected to one supply to the lamp 24, and the other supply to the lamp 24 through the contacts 185b is directly connected to the ground wire 174. In the event of a power failure, the contacts 185b will therefore remain closed two or three minutes, and during i

of this time, the lamp 24 will continuously

is energized for two or three minutes, which will allow two or three revolutions of the aperture disc 25 and produce a single mark on the film 143, which instant-

keling will indicate a power failure.

It was pointed out above that the output voltage

output from the decimal-to-binary converter was a relatively low voltage of less than 20 volts, and to eliminate any problems of failure to

break down any resistance film between

lom the rotating contact arm 162 and con-

bars 169, a so-called voltage injection circuit is fitted which transfers a direct current potential of a predetermined height to the switch contacts on the contact sensor 21.

This voltage injection circuit, which is described in the following, does not form part of the present invention, but is produced and protected in US patent no.

2,758,223. For this purpose, a pas-

send voltage parts, comprising resistors 212 and 213, connected between one end of the secondary winding 172 of the transformer 170 and earth, and with the help of rectifier 214 a negative potential is obtained

sial of 100 volts at end 215. A suitable smoothing capacitor 216 is connected between end 215 and ground 174. This high negative potential is, by means of led-

ning 217 and a large resistance 218 for

connected with the rotating contact arm 162 through the switch 194 and the resistor 195. The resistor 218 should ideally have a resistance

value about one thousand times the resistance

that in 195. Furthermore, resistance is 195 if-

trained of the same order of magnitude as the output impedance of the decimal-to-binary converter 16. As long as no current fly-

ter through the rotating arm 162, on-

the rotating arm is pressed a relatively high negative potential in addition to the smaller positive potential present on the con-

bars 169. The sum of these voltages breaks down any resistive film that may be present. But as soon as current flows, the voltage drop across the resistor 218 will be so great that only a fairly small voltage, in fact only a fraction of the output voltage from the converter 16 is applied by the voltage injection circuit,

so that it cannot affect the operation

nene in the thyratron 179.

Considering the detailed infor-

mation given above, the operation of the present invention will easily be

understandable, and further discussion of this is not given. As the rotary contact

arm 162 rotates and in sequence ends

14

contacts 169e, 169f, 169g and 169h, code signals will be given to the register tape 143

in binary code representative of voting

gene of the receiver 10. The signal that

brought onto the register tape by contact 169d,

indicates that the receiver 10 is connected, even if it did not have to be tuned to any of the fifteen channels provided in the recorder 20. The low output voltage

ning from the decimal-to-binary converter 16 easily energizes the lamp through the thyratron amplifier. At the same time, the very low voltage means no risk of fire or electric shock, and the cable 17 can be placed anywhere with great confidence. Than-

furthermore, with completely passive impedance elements, a completely foolproof arrangement has been produced without any of the possible uncertainties that could arise

where rotary code switches were used.

With the present invention, information from all receivers in a single home can be easily recorded on a single film, whereby the employee, by replacing magazines containing the film, cannot make any mistakes with regard to

bin the correct magazine with the correct receiver, since only one maga-

his.

Claims (8)

1. Device comprising a converter more for converting a tuning signal appearing in electrical form on a single one of a plurality of input conductors into a binary signal appearing in electrical form on a plurality of output conductors, which binary signal is intended for use in a recording apparatus making a recording or recording of the radio stations to which a radio device is tuned, characterized in that there is arranged a group of input conductors (70) representing a group of whole numbers, a group of output conductors (71) representing respective digits in a binary number system, a first group of impedances (106 —109) connecting the output conductors to a voltage reference point (114), another group of impedances (72—104) connecting the respective input conductors (70) to the various output conductors (71) representing the binary number corresponding to the corresponding input conductor, and a switch (15) with a series of contacts (44, 45) to optionally connect one of the input conductors (70) corresponding to the number to be is transformed with a point (58) whose voltage is different from the voltage in the aforementioned voltage reference point whereby the electrical voltages produced in the output conductors (71) form a binary representation of the one of the input conductors that is selected. 2. Device as stated in claim 1, characterized in that every other input conductor (70a, 70c, 70e, etc.) is connected to the first output conductor (71a) via resistors (72—79), that the input conductors, possibly with the exception of one conductor, is divided into successive groups (two-groups) of two conductors (70b—70c, 70d—70e, etc.) of which each two-group, which comprises an input conductor which is connected to the first output conductor and an input conductor which is not is connected to the first output conductor, is connected to the second output conductor (71b) via resistors (80—87), that the input conductors, possibly with the exception of 3 or fewer conductors, are further divided into successive groups (groups of four) of four conductors (70d—70g, 70h —70k, etc.) of which each group of fours, comprising a group of twos connected to the second output conductor, and a group of twos not connected to the second output conductor, is connected to the third output conductor (71c) over resistor (88-95), that the input conductors, e possibly with the exception of 7 or fewer conductors, further divided into successive groups (groups of eight), of eight conductors (70h— 70q) of which each group of eight, which includes a group of four which is connected to the third output conductor and a group of four not connected to the third output conductor is connected to the fourth output conductor (71d) across resistors (97-104), etc., the number of input conductors in each group being doubled from one output conductor to the next. 3. Device as stated in claim 2, characterized in that each output conductor (71) is grounded across a separate resistance (106-109). 4. Device as stated in claim 3, characterized in that the resistances (106-109) over which the output conductors (71) are grounded are small compared to the resistances (72-104) which connect the input conductors to the output conductors. 5. Device as stated in one of claims 2-4, characterized in that the input conductors (70a, 70b, 70d, 70h) which each have a connection with only one output conductor (respectively 71a, b, c and d) are connected with relevant output conductor across a resistance (respectively 72, 80, 88 and 97) which is smaller than the other resistances (73—79, 81—87, 89—95, 98—104) which connect the input conductors to the output conductors. 6. Device as stated in any of the preceding claims, characterized in that the output conductors (71) are connected to fixed contacts (169) on a contact sensor (21) which rotates synchronously with a diaphragm (25) and whose rotating contact arm (162) ) scans these contacts and controls a registration lamp (24). 7. Device as stated in claim 6, characterized in that the rotating contact arm (162) is connected to the control grid in an amplifier tube (179) which controls the switching on and off of the registration lamp (24). 8. Device as stated in claim 6 or 7, characterized in that the output conductors from several converters, which are assigned to a special receiver, are connected to fixed contacts (169) on the rotary contact transmitter (21) in order to obtain, on the same recording means, registration from multiple recipients.