System and method for daisy-chain addressing in speaker systems

Abstract

To provide a speaker system with built-in arrangement for self-testing and a method for testing the speaker system.SOLUTION: A speaker system 100 comprises: a main unit 101 for generating a control voltage, a reference voltage, and an audio signal to a plurality of passive units 102; the plurality of passive units 102 connected by at least a control voltage signal connection 110, a reference voltage signal connection 111 and an audio signal connection 112 to form a daisy chain; and a voltage regulation unit 120 for providing a local reference voltage to each passive unit. Each passive unit comprises: a speaker 113; a voltage threshold generator 116 for generating a voltage threshold from the local reference voltage; a comparator 115 for comparing the control voltage with the voltage threshold to an audio enabling signal for enabling reproduction of the audio signal using the speaker 113; and a logic gate 114 for processing comparator digital output.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a speaker system incorporating a mechanism for self-testing and a method for testing a speaker system.

Background Art

[0002] In electronics, daisy chain refers to the practice of connecting devices or components in series one after another using a single wire or connection. This is commonly seen, for example, in power supply configurations where multiple devices are powered in sequence from a single source. Each device in the chain is connected in series to the devices before and after it, forming a chain-like structure.

[0003] Daisy chains are commonly used in many different fields such as data communication, control systems, LED lighting systems, or audio systems. Specifically, in passive speaker systems, multiple speakers can be connected in series. Some systems require multiple speakers to cover a wide area and spread the same sound or the same information to different locations.

[0004] An efficient strategy for placing a network of multiple speakers throughout a room or a relatively large area involves connecting one main unit to the network and supplying power and audio signals to a daisy chain of passive speakers. This approach can minimize the total length or amount of cable used in the network. A common cable wiring solution in speaker systems can include, for example, the use of Ethernet cables, which are generally a cost-effective option in network-connected speaker systems.

[0005] While the system described above is simple and cost-effective in itself, it can make individual speaker testing more difficult. Ideally, passive speakers in a daisy-chain should be as simple as possible to keep the bill of materials to a minimum. However, keeping passive speakers as simple as possible can affect the performance of individual speaker testing. For example, if a passive speaker does not have a local processing unit to control and / or perform testing, individual testing becomes extremely difficult.

[0006] U.S. Patent Application Publication No. 2019 / 356986 discloses an impedance matching device including a transformer having an input side and an output side, the input side including a first coil having a first impedance, a second coil having a second impedance, and a third coil having a third impedance. An input power connector is electrically connected to the input side of the transformer, and a pass-through output power connector is electrically connected to the input side of the transformer, and the pass-through output connector is also electrically connected in parallel to the input power connector. A speaker output connector having four electrical contacts is included, the first pair of the four electrical contacts being electrically connected to the first coil, and the second pair of the four electrical contacts being electrically connected to the second coil. [Overview of the project]

[0007] This disclosure relates to a speaker system incorporating a mechanism for self-testing and a method for testing the speaker system. The disclosed system and method address the challenge of individually testing speakers by a configuration that allows each of several connected passive speakers to be individually enabled using a control voltage signal connection and a reference voltage signal connection.

[0008] This speaker system comprises a main unit and multiple passive units, which are connected to form a daisy-chain by at least control voltage signal connections, reference voltage signal connections, and audio signal connections. This speaker system comprises a main unit and multiple passive units, which are configured to test the multiple passive units individually, and which are connected to form a daisy-chain by at least control voltage signal connections, reference voltage signal connections, and audio signal connections. The main unit is, Control voltage to multiple passive units via control voltage signal connection, Reference voltage to multiple passive units via reference voltage signal connection, and Audio signals to multiple passive units via audio signal connection. The speaker system is configured to generate a local reference voltage between each of several passive units on a reference voltage signal connection, each voltage regulating unit being adapted to provide a local reference voltage to each passive unit, and the local reference voltage to the several passive units gradually increases or decreases between the passive units following along the daisy chain. Each of the multiple passive units is, Speaker unit and A comparator unit configured to compare a control voltage with a first voltage threshold and a second voltage threshold generated from a local reference voltage, and to generate an audio enable signal that allows the speaker unit to reproduce an audio signal when the control voltage is between the first voltage threshold and the second voltage threshold. Equipped with, The main unit receives feedback from each passive unit.

[0009] The term "daisy-chain" should be interpreted broadly to include configurations in which cables are connected from a main unit to passive units by one or more overall connections or cables, but the passive units may have local parallel branches from this one or more overall connections or cables. Technically, this means that a daisy-chain may include parallel components. To illustrate the concepts and terminology in this regard, Figures 1 and 2 can be referenced. In Figure 1, a main unit 101 and several passive units 102 form a daisy-chain. An audio signal connection 103 connects the main unit 101 and several passive units 102 in a daisy-chain. However, in Figure 2, it can be seen that an audio signal connection 112 may have parallel connections to all passive units 102. The term "daisy-chain" should be interpreted broadly to include such configurations. The main unit is configured to generate control voltages to a plurality of passive units via a control voltage signal connection, reference voltages to a plurality of passive units via a reference voltage signal connection, and audio signals to a plurality of passive units via an audio signal connection. The speaker system further comprises voltage adjustment units between each of the plurality of passive units on the reference voltage signal connection, the voltage adjustment units may be one or more resistors, each voltage adjustment unit is adapted to provide a local reference voltage to each passive unit, the local reference voltages to the plurality of passive units gradually increase or decrease among the passive units following along the daisy chain, and each of the plurality of passive units comprises a speaker unit and a comparator unit configured to compare the control voltage with a first voltage threshold and a second voltage threshold generated from the local reference voltage and generate an audio enable signal that allows the speaker unit to reproduce an audio signal when the control voltage is between the first voltage threshold and the second voltage threshold.

[0010] Each of the multiple passive units may include a comparator unit configured to compare a control voltage to a first voltage threshold and a second voltage threshold generated from a local reference voltage. Each passive unit has its own unique local reference voltage by having a reference voltage that increases or decreases along the chain of passive units. The local reference voltage and control voltage can be used to individually enable speaker units within the passive units. An audio enable signal can be enabled in each of the multiple passive units by using two connections, namely a control voltage signal connection and a reference voltage signal connection. The number of connections for generating the audio enable signal in a passive unit, which in the above case is two connections or two signals, may be independent of the number of multiple passive units, which may be at least two, preferably at least five, more preferably at least ten, and even more preferably at least twenty passive units.

[0011] By using the speaker system of this disclosure, certain expensive and / or complex components, such as processing units, can be excluded from passive speakers while maintaining the possibility of testing speakers individually. Conveniently, the main unit can handle most of the functionality, and this functionality can be provided to multiple passive units simply by using control voltage signal connections, reference voltage signal connections, and audio signal connections.

[0012] Furthermore, the present disclosure relates to a method for testing a speaker system comprising a main unit and a plurality of passive units, wherein the main unit and the plurality of passive units are connected to form a daisy chain by at least a control voltage signal connection, a reference voltage signal connection, and an audio signal connection, the method comprising: providing each passive unit with a local reference voltage by generating a reference voltage on the reference voltage signal connection that gradually increases or decreases among the passive units that follow along the daisy chain; providing a control voltage on the control voltage signal connection; generating audio signals to the plurality of passive units via the audio signal connection; in each passive unit, comparing the control voltage to a first voltage threshold and a second voltage threshold generated from the local reference voltage, generating an audio enable signal that enables the speaker unit of the passive unit to reproduce the audio signal when the control voltage is between the first voltage threshold and the second voltage threshold; and testing each passive unit by receiving feedback from each passive unit.

[0013] This method can provide a method for testing a speaker system, which comprises a main unit and multiple passive units. With one reference voltage and one control voltage, the speaker system can individually enable the speakers in each of the multiple passive units, and the reference voltage can be used to generate a local reference voltage to each passive unit. Each of the multiple passive units can be tested by playing an audio signal through the speakers. The audio signal played by the speakers can be recorded by the main unit via a microphone. An alternative test can be performed by measuring or monitoring the supply current derived from the supply voltage, which is provided to the multiple passive units by the main unit. As soon as an audio signal is played through the speaker of one of the multiple passive units, the supply current can be monitored via the supply voltage connection, thereby allowing the speaker of one of the multiple passive units to be tested.

[0014] The speaker system may be configured so that only one passive unit reproduces an audio signal at a time. This can be used to test whether a particular speaker unit is functioning. This can be achieved by the method described herein, in which the main unit provides a sweep control voltage via a control voltage connection that addresses a particular passive unit connected in a daisy chain by comparing the control voltage to first and second voltage thresholds.

[0015] A local reference voltage is provided to each passive unit by gradually increasing or decreasing the reference voltage. The main unit can provide a control voltage, such as a pulse-width modulation (PWM) control voltage signal, via a control voltage signal connection, which can be configured to enable or disable specific passive units in the daisy chain.

[0016] Various embodiments are described below with reference to the drawings. The drawings are non-limiting examples of embodiments and are intended to illustrate some of the features of the speaker system and method for testing the speaker system of this disclosure. [Brief explanation of the drawing]

[0017] [Figure 1] This specification shows a schematic diagram of one embodiment of the speaker system disclosed herein. [Figure 2] This specification includes schematic diagrams of one embodiment of the speaker system disclosed herein, which include schematic diagrams of a plurality of passive units. [Figure 3] A schematic diagram of one embodiment of multiple passive units is shown, illustrating the electrical connections. [Figure 4] This shows an example of triggering a control voltage and enable signal that sweeps from a first level to a second level in a passive unit. [Figure 5] This diagram shows a schematic representation of one embodiment of the eight conductors included in an Ethernet cable that connects the main unit in series with the passive unit. [Modes for carrying out the invention]

[0018] The present disclosure relates to a speaker system comprising a main unit and a plurality of passive units, the main unit and the plurality of passive units being connected by at least a control voltage signal connection, a reference voltage signal connection, and an audio signal connection, the main unit being configured to generate a control voltage via the control voltage signal connection, a reference voltage via the reference voltage signal connection, and an audio signal via the audio signal connection, further comprising voltage adjustment units between each of the plurality of passive units on the reference voltage signal connection, each voltage adjustment unit being adapted to provide a local reference voltage to each of the plurality of passive units, the local reference voltage to the plurality of passive units increasing or decreasing between consecutive passive units, and each of the plurality of passive units comprising a speaker and a comparator configured to compare a control voltage with a first voltage threshold and a second voltage threshold generated from the local reference voltage and to generate an audio enable signal that enables the speaker to reproduce an audio signal when the control voltage is between the first voltage threshold and the second voltage threshold.

[0019] Figure 1 shows a schematic diagram of one embodiment of speaker system 100. Speaker system 100 comprises a main unit 101 and several passive units 102 connected by at least a control voltage signal connection, a reference voltage signal connection, and an audio signal connection 103 to form a daisy chain. Each passive unit 102 comprises a speaker unit 104 and a comparator unit 105. Figure 1 shows the main unit 101 and four passive units 102. Further passive units may be connected after the fourth passive unit. All passive units comprise a speaker unit 104 and a comparator unit 105. By connecting the main unit and passive units in a daisy chain arrangement, a reduction in the complexity of the speaker system is achieved. The use of a daisy chain configuration can be cost-effective because it reduces the amount of cabling required and the need for additional equipment is reduced. It should be noted that the term "daisy-chain" may be interpreted broadly to include configurations in which cables are connected from a main unit to passive units by one or more global connections or cables, but the passive units have local parallel branches from this one or more global connections or cables. Technically, this means that a daisy-chain may include parallel components. It is easier to add further passive units because users can easily connect at least one additional passive unit to an existing chain without significant modifications. Centralized control can be achieved by having a main unit.

[0020] In one embodiment, the voltage adjustment unit includes a resistor. The resistor may be a fixed resistor, a variable resistor such as a rheostat or a potentiometer, and / or a special resistor such as a thermistor or a varistor. Preferably, a fixed resistor can be used to keep the system simple while limiting the cost of any other alternative that may be more expensive. The voltage adjustment unit can include a voltage drop device configured to cause a voltage drop. The voltage drop device may be a diode such as a Zener diode, an LED, a transistor configured to generate a voltage drop such as an NMOS device or a PMOS device, or any other suitable element or component for generating a voltage drop. A bipolar junction transistor may be used according to the same principle, and in the case of NPN, the collector junction is short-circuited with the base junction. An inductor can also have a series resistance used to generate a voltage drop, and thus an inductor can also be used as a voltage drop device. Interconnections such as cables and / or copper wiring can have a series resistance. In this case, the interconnection that can connect the main unit to a plurality of passive units can also be used for generating a voltage drop.

[0021] Alternatively, the speaker system may be designed such that the reference voltage increases along the chain of passive units. This can be achieved by the higher voltage at one end of the chain and the voltage drop in the opposite direction of the chain. Theoretically, the voltage adjustment unit can even include a voltage boost unit. The voltage boost unit can include a DC-DC converter such as a boost converter, and / or a charge pump such as a switched capacitor DC-DC converter.

[0022] In a preferred embodiment, the voltage adjustment unit includes a resistor. The resistor can have a resistance between 1 kΩ and 1 MΩ, such as between 1 kΩ and 500 kΩ, or between 1 kΩ and 100 kΩ, or between 1 kΩ and 80 kΩ, or between 1 kΩ and 50 kΩ, or between 1 kΩ and 40 kΩ, or between 1 kΩ and 30 kΩ, or between 1 kΩ and 20 kΩ, or between 1 kΩ and 10 kΩ, or between 1 kΩ and 5 kΩ, or between 1 kΩ and 2 kΩ. A typical value of the resistor useful for this purpose is 10 kΩ. If the resistance value is high, the voltage drop will be large, which may make the use of the speaker system difficult. If the resistance value is low, the voltage drop may be small. Considering the general impedance of various nodes in the speaker system, a compromise point can be found. Some nodes may have low or high impedance, and the value of the resistor can be appropriately selected to allow a relatively large voltage drop between each of the plurality of passive units while minimizing the current leakage through the nodes.

[0023] The speaker system can include at least two, or at least five, or at least ten, or at least twenty passive units. Each passive unit can be connected to form a daisy chain. A daisy chain can refer to a configuration of wiring or connections where devices are connected in series one after another, preferably in a linear manner. This term can be used to describe a method of interconnecting devices or components in a way that forms a chain-like structure. In the present disclosure, the main unit and the plurality of passive units can be connected to form a daisy chain. All connections such as the control voltage signal connection, the reference voltage signal connection, and the audio signal connection can be included in the interconnecting cable, which is used to interconnect or connect the main unit and the plurality of passive units.

[0024] In one embodiment, the first voltage threshold and / or the second voltage threshold lie between 0 V and the local reference voltage. The first voltage threshold and / or the second voltage threshold may be generated from the local reference voltage. The first voltage threshold and / or the second voltage threshold can be generated by applying a voltage transformation to the local reference voltage, which may be a voltage drop or a voltage rise.

[0025] In one embodiment, a plurality of passive units comprises first and second voltage threshold generators. The first and second voltage threshold generators can be configured to generate first and second voltage thresholds. Preferably, the first and second voltage threshold generators may be configured to generate first and second voltage thresholds from a local reference voltage. The local reference voltage may be the inputs to the first and second voltage threshold generators. The first and second voltage threshold generators may comprise at least one passive device and / or at least one active device.

[0026] Each passive unit can be configured to generate a first voltage threshold and / or a second voltage threshold by voltage division. Voltage division can be performed by a voltage divider. Voltage division, which will generally be known to those skilled in the art, is a common technique used in electronics to distribute voltage to multiple resistors in a series circuit, preferably by a voltage divider.

[0027] In a preferred embodiment, the voltage divider comprises two voltage divider resistors, which are arranged in series between the local reference voltage and ground. Each of the two voltage divider resistors may have a voltage divider resistor, which may be selected so that a useful first or second voltage threshold is provided by the voltage division. The first voltage threshold may be lower than the second voltage threshold, but in principle, the opposite may also work. By using a voltage divider with two voltage divider resistors, an inexpensive and simple solution can be achieved for generating first and / or second voltage thresholds from the local reference voltage. As mentioned above, if the resistance of the voltage divider is too low, unwanted current leakage from the local reference voltage and ground may occur, and if the resistance of the voltage divider is too high, the voltage drop between each of the multiple passive units may be small for a given resistance of the resistors included in the voltage regulating unit. To avoid the need to decide on a compromise, an impedance buffer may be included in the voltage regulating unit. The impedance buffer may be a buffer amplifier. A buffer amplifier can be used to provide high and low input impedances. This allows for the isolation or separation of one part of the circuit from another, preventing load effects. Some common types of impedance buffers may include: • Operational amplifier (op-amp) buffer: Using an operational amplifier configured in voltage follower (gain 1) mode creates a buffer with high input impedance and low output impedance. • Emitter follower buffer: A transistor configured as an emitter follower provides a buffer with low output impedance and a voltage gain of 1. • Source follower buffer: A transistor configured as a source follower (common drain) provides a buffer with low output impedance and a voltage gain of 1. • Voltage follower buffer: A simple voltage follower circuit using an amplifier with a gain of 1, such as an operational amplifier, functions as an impedance buffer. • FET (Field-Effect Transistor) Buffer: An FET configured as a source follower can function as a buffer, providing a low output impedance. • Transformer-based buffers: Transformers can be used to generate impedance buffers, particularly in audio applications. The primary and secondary windings provide isolation and impedance matching.

[0028] The comparator unit may comprise at least two comparators, the first of which may be configured to compare a first voltage threshold with the control voltage, and the second comparator to compare a second voltage threshold with the control voltage. By having two comparators that compare a first voltage threshold and a second voltage threshold with the control voltage, a voltage window can be defined, and thus a voltage range in which the control voltage is higher than the first voltage threshold and lower than the second voltage threshold (and vice versa if the second voltage threshold is lower than the first voltage threshold) can be identified.

[0029] The first comparator can generate a first comparator digital output, and the second comparator can generate a second comparator digital output. The first and second comparator digital outputs can then be used to define a voltage range as described above, and the digital outputs can be further used in a digital circuit.

[0030] The first and second comparator digital outputs may be inputs to a logic gate. By inputting the first and second comparator digital outputs to a logic gate, a digital decision based on the outputs of the two comparators can be performed by the logic gate. The digital decision may be true if the control voltage is between the first and second voltage thresholds, and false if the control voltage is not between the first and second voltage thresholds.

[0031] In one embodiment, a logic gate is configured to output an audio enable signal in response to an input. The audio enable signal may depend on a digital decision, as described in the preceding paragraph. The digital decision may depend on the input. The audio enable signal can be used to activate an amplifier that can use the audio signal for playback through a speaker.

[0032] The logic gate may be an XOR gate or an AND gate. The logic gate may be selected such that an accurate digital decision is obtained as the output of the logic gate. An AND gate may be accurate when both comparators output a high digital output and the control voltage is between the first and second voltage thresholds. An XOR gate may be accurate when one comparator outputs a high digital output and the other comparator outputs a low digital output and the control voltage is between the first and second voltage thresholds.

[0033] Figure 2 shows a schematic diagram of one embodiment of the speaker system 100 disclosed herein, which shows a schematic diagram of a plurality of passive units 102. Each of the plurality of passive units comprises first and second voltage threshold generators 116, two comparators 115, a logic gate 114, and a speaker 113. The speaker may be a speaker unit described herein. The speaker unit may include a speaker amplifier, and / or any other auxiliary devices or systems that can be used in combination with the speaker or sound emitting device. The main unit is configured to generate control voltages to the plurality of passive units via a control voltage connection 110, audio signals to the plurality of passive units via an audio signal connection 112, and reference voltages to the plurality of passive units via a reference voltage connection 111. A voltage adjustment unit 120 is positioned between each of the plurality of passive units on the reference voltage signal connection 111. The voltage regulating unit 120 is adapted to provide a local reference voltage to each passive unit. A voltage difference can exist across the voltage regulating unit 120. This causes the reference voltage to decrease or increase along the reference voltage signal connection in the chain of passive units 120. The user can configure the voltage regulating unit so that the reference voltage gradually increases or decreases between passive units following each other in a daisy chain. By gradually increasing or decreasing the reference voltage, at least one local reference voltage can be generated, and therefore a unique local reference voltage can be generated for each of the multiple passive units. The speaker 113 receives an audio signal from the audio signal connection 112. The first and second voltage threshold generators 116 are configured to generate first and second voltage thresholds from the local reference voltage provided by the reference voltage signal connection 111. Each passive unit has its own local reference voltage and therefore its own first and second voltage thresholds. Two comparators 115 are arranged in multiple passive units, and the comparators are configured to compare first and second voltage thresholds with a control voltage, which is provided by a control voltage signal connection 110.The first comparator generates a first comparator digital output, and the second comparator generates a second comparator digital output. The first and second comparator digital outputs are processed by a logic gate, which outputs an audio enable signal to activate speaker 113. Preferably, the logic gate is selected so that the audio enable signal is activated or reaches a high logic level when the control voltage is between the first and second threshold signals. A high logic level or high logic state can represent the binary value 1 in binary, indicating a high digital voltage level or a true logic state. A high logic level or low logic level represents a binary state used in digital electronic devices, with high and low voltages corresponding to logic 1 and 0, respectively. By activating speaker 113, the audio signal provided by the audio signal connection 112 can be played by speaker 113 and thus heard by the user or an audio capture device. The audio capture device may be included in a passive unit, a main unit, or a secondary system, preferably at a distance from the speaker that allows it to capture sound emitted by the speaker.

[0034] Figure 3 shows a schematic diagram of one embodiment of a plurality of passive units, illustrating its electrical overview. In this example, each passive unit comprises first and second voltage threshold generators 116, the first and second voltage thresholds being generated by a voltage divider, each of which comprises two resistors. The resistance values ​​of the two resistors are selected such that the first and second voltage thresholds are different voltages. The voltage adjustment unit 120 is a resistor. By placing the resistor in the reference voltage signal connection, a voltage drop can be made between each passive unit, and thus different local reference voltages can be generated for each of the plurality of passive units. The voltage drop made between each passive unit depends on the resistance value of the resistor and the current flowing from the reference voltage generator 301 into the resistor. The current flowing into the resistor depends on the resistance value of the resistor in combination with the resistors placed in the first and second voltage threshold generators 116. It may be advantageous to determine a resistance value sufficient to produce a sufficient voltage drop between local reference voltages while minimizing the amount of current supplied to the reference voltage signal connection 111. A method for determining a ratio that will satisfy a sufficient voltage drop while minimizing the amount of current supplied to the reference voltage signal connection by the reference voltage generator 301 is generally known to those skilled in the art. The reference voltage generator 301 may be located in the main unit. First and second voltage thresholds are generated from the local reference voltages generated from the reference voltage signal connection 111. The first and second voltage thresholds are then compared to a control voltage in two comparators 115. The input connections of the two comparators are a particular embodiment, and embodiments should not be limited to this particular embodiment shown in Figure 3. The two comparators output first and second comparator digital outputs. Pull-up resistors and / or pull-down resistors are placed at the first and second comparator digital outputs to ensure known states at the first and second comparator digital outputs. As explained in relation to Figure 2, the first and second comparator digital outputs are processed by logic gate 114, which outputs an audio enable signal that activates the speaker (not shown in Figure 3).

[0035] Figure 4 shows an example of a control voltage being swept from a first level to a second level, with a local enable signal triggered in each of the four passive units. In this example, the first level at the start of the process is 0 V, and the second level at the end of the process is 38 V. Those skilled in the art will understand that these two levels can be adjusted to suit the situation and the number of passive units. For one of the passive units, the first and second voltage thresholds are configured to be generated at 27 V and 29 V, respectively. The first and second voltage thresholds shown in Figure 4 are generated by one of the passive units. As can be seen in Figure 4, the local audio enable signal for the passive unit is set to high in digital logic when the control voltage is between the first and second voltage thresholds. As soon as the control voltage exceeds the first voltage threshold, the audio enable signal becomes high in digital logic, which is 5 V in this particular embodiment. As soon as the control voltage exceeds the second voltage threshold, the audio enable signal becomes a low in digital logic, which in this particular embodiment is 0 V. By sweeping the control signal between the first and second voltage thresholds, or preferably setting the control signal between the first and second voltage thresholds, the audio enable signal can be activated for a particular passive unit having the first and second voltage thresholds, thus enabling the speaker to reproduce the sound provided by the audio signal connection. In the diagram of Figure 4, it can be noted that the enable signal is activated four times, namely at 0.5 seconds, a little after 1.0 seconds, and between 1.5 seconds and 2.0 seconds, and finally at 2.5 seconds. In this example, the four instances of the enable signal represent four different local enable signals in four different passive units.

[0036] The speaker system may further include supply signal connections and / or ground signal connections.

[0037] The main unit may be further configured to generate supply signals to multiple passive signal units via supply signal connections.

[0038] The supply signal may be a supply voltage, which may be between 1.5V and 120V, for example 1.5V and 96V, for example 1.5V and 48V, for example 1.5V and 24V, for example 1.5V and 12V, for example 1.5V and 9V, for example 1.5V and 5V, for example 1.5V and 3.3V. The supply voltage may also be a standard supply voltage for Ethernet cables, such as a supply voltage between 12V and 57V or between 37V and 57V.

[0039] The main unit may be further configured to generate ground signals to multiple passive signal units via ground signal connections. The ground signal may be a ground voltage. The ground voltage may be, for example, 0V. In most actual electronic systems and electronic circuits or systems, the term “ground” can be used as a reference point and can conventionally be considered to be 0V. However, ground can also have a positive or negative voltage. Ground can also be called a reference point that serves as the reference for all voltages used in the system.

[0040] The main unit and multiple passive units can be connected by at least five conductors configured to provide at least supply signal connections, ground signal connections, reference signal connections, audio signal connections, and control signal connections.

[0041] The main unit and multiple passive units can be connected by at least eight conductors. Having eight conductors allows for greater flexibility in the various connections described above, such as control voltage signal connections, reference voltage signal connections, audio signal connections, supply signal connections, and / or ground signal connections. For example, two cables can be used for supply signal connections and / or ground signal connections.

[0042] Ethernet cables may contain at least five conductors or at least eight conductors. Ethernet cables are a type of cable primarily used to connect devices within a local area network for the purpose of transmitting data. Ethernet cables can also be used to transmit power. Ethernet cables are defined by standards established by the Institute of Electrical and Electronics Engineers (IEEE). Ethernet cables have connectors at each end, commonly known as RJ45 connectors. This allows for the promotion and cost reduction of systems that conform to such technology, as the technology is widely used and available. Ethernet cables can also be used for Power over Ethernet (PoE) implementations. The speaker system of this disclosure, with a built-in configuration for self-testing, can use Ethernet cables to supply power but can operate without communication via the PoE protocol. Power over Ethernet allows power to be transmitted over the same Ethernet cable used to interconnect devices or units by data communication. The selection of the category of Ethernet cable may be important in PoE applications. Higher categories such as Cat5, Cat5e, Cat6, Cat6a, or Cat7 are often preferred due to their higher power transmission capacity and lower power loss over longer cable lengths. When used in Power over Ethernet applications, Ethernet cables can provide a convenient and efficient way to power and connect network devices, reducing the need for additional power cables and simplifying installation in various environments.

[0043] It is possible to provide a supply signal connection using a single conductor. In one embodiment, at least two conductors are configured to provide a supply signal connection. Having at least two conductors configured to provide a supply signal connection can reduce the supply voltage drop. Two parallel conductors can reduce the series resistance of the supply signal connection by half. More preferably, the series resistance of the supply signal connection can be further reduced by using three or more conductors in parallel. A compromise can be found that minimizes the number of cables used for the supply signal connection while keeping the series resistance of the supply signal connection low.

[0044] In another embodiment, at least two conductors are configured to provide a ground signal connection. Having at least two conductors configured to provide a ground signal connection can reduce the supply voltage drop. Preferably, two conductors used in parallel can reduce the series resistance of the ground signal connection by half. More preferably, using three or more conductors in parallel can further reduce the series resistance of the ground signal connection. A compromise can be found that minimizes the number of cables used for the ground signal connection while keeping the series resistance of the ground signal connection low. The inventors of the present invention have found that at least two conductors can be used to reduce the series resistance of the ground signal connection to an acceptable level.

[0045] Audio signal connections may be differential audio signal connections. Therefore, audio signals may be differential audio signals. Due to several advantages related to noise rejection, common-mode rejection, and overall signal quality, differential audio signal transmission may be preferred over single-ended audio signal transmission in many applications or systems. Differential signal transmission can help reject common-mode noise. Common-mode noise refers to interference present in both positive and negative signal lines in the same direction. In differential signaling, common-mode noise is canceled out because the receiver responds only to the difference between the two signal lines. This increases the system's immunity to external noise sources. The common-mode rejection ratio (CMRR) is a measure of how effectively a system rejects common-mode signals. Differential signal transmission provides a high CMRR because common-mode noise is canceled out. This is especially important in environments with strong electromagnetic interference (EMI) or radio frequency interference (RFI). Differential signal transmission may be more preferable for longer cable lengths. In single-ended systems, long cables can act as antennas and pick up additional noise. Common-mode noise is noise picked up by both signal lines, and differential receivers can effectively eliminate this noise. Operating signal transmission can help maintain signal quality by reducing the effects of external interference and noise. This may be preferable in high-fidelity audio applications where maintaining original signal quality is advantageous. In single-ended systems, ground loops can contribute to signal noise. Differential signal transmission helps minimize the effects of ground loops because common-mode noise induced on the ground line is eliminated by the differential receiver. Operating signal transmission can enable an increased dynamic range in audio systems. This allows for a wider range of signal amplitudes without distortion, providing more headroom for audio signals.

[0046] In one embodiment, the audio signal connection is configured to use at least two conductors. By using at least two conductors, a first conductor can provide the positive side of the differential audio signal, while a second conductor can provide the negative side of the differential audio signal, thus providing a differential audio signal.

[0047] Figure 5 shows a schematic diagram of one embodiment of eight conductors included in an Ethernet cable connecting a main unit 101 in series with a passive unit 102. The main unit 101 is connected in series with the passive unit 102 by eight conductors. Two of the eight conductors are configured to provide a supply signal connection 501, and two of the eight conductors are configured to provide a ground signal connection 502. Two of the eight conductors are configured to provide an audio signal connection 112. One of the eight conductors is configured to provide a control voltage signal connection 110, and another of the eight conductors is configured to provide a reference voltage signal connection 111.

[0048] Furthermore, the present disclosure relates to a method for testing a speaker system which may comprise a main unit and a plurality of passive units, the main unit and the plurality of passive units being connected to form a daisy chain by at least a control voltage signal connection, a reference voltage signal connection and an audio signal connection, the method which may include providing each passive unit with a local reference voltage by generating a reference voltage on the reference voltage signal connection that gradually increases or decreases among the passive units following along the daisy chain; providing a control voltage on the control voltage signal connection; generating audio signals to the plurality of passive units via the audio signal connection; in each passive unit, comparing the control voltage to a first voltage threshold and a second voltage threshold generated from the local reference voltage, generating an audio enable signal that enables the speaker unit of the passive unit to reproduce the audio signal when the control voltage is between the first voltage threshold and the second voltage threshold; and testing each passive unit by receiving feedback from each passive unit.

[0049] In one embodiment, feedback is received by a main unit. The main unit may include a secondary system which may be configured to process the feedback. The feedback can be processed by the secondary system so that the information contained in the feedback can generate an action that the main unit should take. Preferably, if the feedback provides information that one of a plurality of passive units may have a malfunction, such as a speaker not functioning, the main unit can generate a signal to inform the user that at least one of the plurality of passive units may require maintenance or replacement for at least one of the features contained in that at least one passive unit.

[0050] The feedback may be a feedback current. The main unit and multiple passive units can be connected by a supply voltage connection. The supply voltage connection can generate a supply voltage. Thus, the feedback current may be a supply current driven by the supply voltage. Preferably, the main unit can generate power that can be supplied to multiple passive units by the supply voltage connection. Conveniently, the supply current can be monitored or recorded by the main unit. By monitoring or recording the supply current provided by the supply voltage connection, fault detection in each of the multiple passive units can be detected. Conveniently, the resulting supply current can be measured or monitored by the main unit via the supply voltage connection by generating an audio enable signal that enables the speaker unit in the passive unit to reproduce the audio signal when the control voltage is between a first voltage threshold and a second voltage threshold. When the audio signal is reproduced by the speaker unit and the speaker unit is functioning as expected, an AC signal reflecting the characteristics of the audio signal should be measured over the supply current. Furthermore, if the speaker unit is not functioning, an incorrect DC supply current may be measured, specifically, a significant portion of the AC signal may be absent.

[0051] The feedback current can be a spike current caused by the operation of the speaker unit. The speaker unit's operation allows monitoring of the spike current following its operation. This can indicate that the speaker unit is functioning correctly.

[0052] The main unit, and / or at least one of the multiple passive units, may include at least one microphone. The main unit, and / or at least one of the multiple passive units, may include at least one audio capture device. The at least one microphone may be a condenser microphone, a dynamic microphone, or a ribbon microphone. A condenser microphone uses a diaphragm and a backplate to form a capacitor. Condenser microphones are known for their sensitivity and ability to capture a wide frequency range. A dynamic microphone generates an electrical signal using electromagnetic induction. Dynamic microphones are known for being robust, versatile, and not requiring an external power supply. A ribbon microphone uses a thin piece of metal suspended in a magnetic field. Ribbon microphones are known for their smooth and natural sound reproduction. A dynamic microphone may represent a good choice because it can generate captured sound without requiring external power and therefore saves power.

[0053] In a preferred embodiment, the feedback is audio feedback, which is an audio signal reproduced by a passive unit and recorded by at least one microphone. As described herein, by capturing and / or recording the audio feedback, it is possible to detect a fault in each of the multiple passive units. The capture and / or recording of the audio feedback can be performed using at least one microphone, which may be included in the main unit or in at least one of the multiple passive units.

[0054] The method may further include sweeping the control voltage over a control voltage signal connection from a first voltage level to a second voltage level. By sweeping the control voltage over a control voltage signal connection from a first voltage level to a second voltage level, multiple speakers of multiple passive units can be tested. Preferably, each of the multiple passive units can generate its own first and second voltage thresholds. By sweeping the control voltage, continuous operation of speakers of consecutive passive units can be performed. The user can detect the operation of multiple speakers while sweeping the control voltage over a control voltage signal connection. The sweep of the control voltage may be a linear voltage sweep or a step voltage sweep. In a linear voltage sweep, the voltage is linearly increased or decreased over a specified range. In a step voltage sweep, the control voltage is swept in discrete steps. This may be useful for testing a speaker system at a specific voltage level to test a particular passive unit. Preferably, a linear voltage sweep may have a linear voltage sweep gradient. The gradient of the linear voltage sweep can be selected to allow testing of multiple consecutive passive units while providing sufficient time between two consecutive passive units. If the linear voltage sweep of the control voltage over time is too steep, the speakers of consecutive passive units will activate relatively quickly, resulting in insufficient time to detect which speaker of which passive unit can be activated. For example, if the speaker system is placed in an environment with echo, this makes audio feedback difficult because it may be detected as if two different speakers are functioning when only the first speaker is functioning. In other words, the residual sound of the first speaker of the first passive unit may be detected as sound received from the activation of the subsequent speaker of the subsequent passive unit under test.

Claims

1. A speaker system comprising a main unit and a plurality of passive units, configured to test the plurality of passive units individually, The main unit and the plurality of passive units are connected to form a daisy-chain by at least control voltage signal connections, reference voltage signal connections, and audio signal connections. The aforementioned main unit is Control voltage to the plurality of passive units via the control voltage signal connection, The reference voltage to the plurality of passive units via the reference voltage signal connection, and Audio signals to the plurality of passive units via the aforementioned audio signal connection It is configured to generate, The speaker system further comprises a voltage adjustment unit positioned between each of the plurality of passive units on the reference voltage signal connection. Each voltage regulation unit is adapted to provide a local reference voltage to each passive unit, and the local reference voltage to the multiple passive units gradually increases or decreases among the passive units following the daisy chain. Each of the aforementioned passive units is Speaker unit and A comparator unit configured to compare the control voltage with a first voltage threshold and a second voltage threshold generated from the local reference voltage, and to generate an audio enable signal that enables the speaker unit to reproduce the audio signal when the control voltage is between the first voltage threshold and the second voltage threshold; Equipped with, The aforementioned main unit is a speaker system that receives feedback from each of the passive units.

2. The speaker system according to claim 1, wherein the voltage adjustment unit comprises at least one resistor.

3. The speaker system according to claim 1, wherein each passive unit is configured to generate the first voltage threshold and / or the second voltage threshold by voltage division using a voltage divider.

4. The speaker system according to claim 1, wherein the comparator unit comprises at least two comparators, the first comparator configured to compare a first voltage threshold with the control voltage, the second comparator configured to compare a second voltage threshold with the control voltage, the first comparator generating a first comparator digital output, the second comparator generating a second comparator digital output, and the first comparator digital output and the second comparator digital output being inputs to a logic gate, the logic gate being configured to output the audio enable signal in response to the input.

5. The speaker system according to claim 1, further comprising a supply signal connection and / or a ground signal connection.

6. The speaker system according to claim 1, wherein the main unit and the plurality of passive units are connected by at least five conductors configured to provide at least a supply signal connection, a ground signal connection, the reference voltage signal connection, the audio signal connection, and the control voltage signal connection.

7. The speaker system according to claim 1, wherein the main unit and the plurality of passive units are connected by eight conductors, the eight conductors being included in an Ethernet cable.

8. A method for testing a speaker system comprising a main unit and a plurality of passive units, wherein the main unit and the plurality of passive units are connected to form a daisy-chain by at least a control voltage signal connection, a reference voltage signal connection, and an audio signal connection, and the method is By generating a reference voltage that gradually increases or decreases between passive units along the daisy chain on the aforementioned reference voltage signal connection, a local reference voltage is provided to each passive unit. Providing a control voltage on the aforementioned control voltage signal connection, To generate audio signals to the plurality of passive units via the aforementioned audio signal connection, In each passive unit, the control voltage is compared with a first voltage threshold and a second voltage threshold generated from the local reference voltage, and an audio enable signal is generated that enables the speaker unit of the passive unit to reproduce the audio signal when the control voltage is between the first voltage threshold and the second voltage threshold. The main unit tests each passive unit by receiving feedback from each passive unit. A method that includes this.

9. The method according to claim 8, wherein the feedback is received by the main unit.

10. The method according to claim 9, wherein the feedback is a feedback current.

11. The method according to claim 8, wherein the feedback current is a spike current caused by the operation of the speaker unit.

12. The method according to claim 8, wherein at least one of the main unit and / or the plurality of passive units comprises at least one microphone.

13. The method according to claim 12, wherein the feedback is audio feedback, and the audio feedback is the audio signal reproduced by the passive unit and recorded by the at least one microphone.

14. The method according to claim 8, further comprising sweeping the control voltage on the control voltage signal connection from a first voltage level to a second voltage level.

15. A method for testing the speaker system according to claim 8, wherein the speaker system is the speaker system according to claim 1.

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