EP3300098B1

EP3300098B1 - Time switch device

Info

Publication number: EP3300098B1
Application number: EP17192779.1A
Authority: EP
Inventors: Remo La Rotonda
Original assignee: Finder SpA
Current assignee: Finder SpA
Priority date: 2016-09-22
Filing date: 2017-09-22
Publication date: 2020-01-15
Anticipated expiration: 2037-09-22
Also published as: EP3300098A1; IT201600095427A1

Description

The present invention relates to an improved time switch device.
Known time switches are used for selectively supplying associated electrical loads (by way of non-limiting example, lighting or signalling devices) at desired dates and/or times. Time switches typically comprise switch elements, such as electromechanical relays, which are suitably controlled for selectively coupling loads to the power supply.
These time switches are also called twilight or astronomical switches when they are able to determine day/night intervals and/or date and time based on their geographic location.
In particular, known digital or programmable time switches allow programming one or more date and/or time schedules for selectively feeding respective electrical loads. Such programming can be done by means of suitable selection and input elements (keys or, in some solutions, joysticks) that can be actuated by the users.
In more advanced solutions, a time switch can also be programmed through wireless communication, such as Near Field Communication (NFC), by using portable electronic devices (e.g. smartphones or tablets) coupled to the time switch.
An example of a time switch provided with NFC communication programming capabilities is described in detail in patent application EP3007195A1 , in the name of the present Applicant.
Generally, time switches are installed in special electrical control panels, e.g. coupled to DIN rails or similar support structures, so as to be accessible to users, e.g. for their programming.
Domestic or industrial electrical systems show an increase in the number and complexity of the electrical loads to be supplied, with a consequent increase in the number of required time switches. This generally results in a corresponding increase in the complexity and size of the resulting electrical control panels.
In particular, some electrical loads, such as LED lighting devices or the like, require appropriate driving signals to control their operation, e.g. PWM (pulse-width modulated) voltage signals, or DC voltage signals ranging between a minimum value, e.g. equal to 0 V, and a maximum value, e.g. 10 V, to adjust the light intensity (a so-called "dimming" operation).
The associated electrical systems have therefore to be provided with suitable driving modules, operatively coupled to the time switches for selectively driving the related electrical loads.
Generally, modern plants therefore show a progressive increase in the number and complexity of the resources required for the selective activation and driving of electrical loads.
WO 01/88645 A1 discloses an appliance comprising means for receiving and recording programming time data, transmitted in the form of signals; executing means for producing an action related to a time mark on the basis of the programming time data; means for receiving synchronising data, transmitted in the form of signals, enabling to operate synchronisation with an external time reference; and time-measuring means, referenced on the basis of the synchronisation data, for providing a time mark to the execution means.
DE 198 15 451 A1 discloses a timer switch system having several distributor housings arranged closely adjacent, of which the first contains a mother switching timer with a quartz clock which controls a switching program that controls switches in the housings. State control signals are passed between adjacent distributor housings via light transmitter-receiver paths, evaluated by individual daughter switching timer circuits and used to actuate the switches.
WO 2012/160432 A1 discloses a time switch having: a master device including a time setting unit that sets a time and a first relay that is provided in a power-feeding path leading to a first load, the master device having the function of controlling the first relay at the time set by the time setting unit; and at least one slave device including a second relay that is provided in a power feeding path leading to a second load. The second relay opens or closes the contact point of the second relay in synchronization with the operation of opening or closing the contact point of the first relay.
The object of the present invention is to solve the previously highlighted problems, and in particular to provide a time switch device allowing an optimized selective activation and driving of electrical loads.
The present invention thus provides a time switch device, as defined in the appended claims.
For a better understanding of the present invention, preferred embodiments are now described, by way of non-limiting example and with reference to the accompanying drawings, wherein:

Figure 1 shows a simplified perspective view of a time switch device according to an embodiment of the present invention;
Figure 2 shows a schematic representation of two distinct electronic modules in the time switch device;
Figure 3 shows a schematic block diagram of the electronic modules of the time switch device;
Figure 4 shows the plot of a digital control signal in the time switch device; and
Figure 5 is a simplified scheme of a possible bit configuration of the digital control signal.

As described in more detail below, an aspect of the present invention involves the provision of a time switch device enclosing in a single casing a plurality of functions, including: a hourly and/or daily scheduling function, with the possible automatic determination of day/night intervals based on geographical location; a switching function designed to provide at least one electromechanical relay output for selectively coupling an associated electrical load to a power source (e.g. to the power supply network); and a driving function designed to provide an analogue output, generating a number of driving signals for associated electrical loads, including, in an embodiment, at least a DC voltage signal comprised between 0 and 10 V and a pulse-width modulated (PWM) voltage signal.
In a possible embodiment, the time switch device is also designed to receive input signals (e.g. state signals), which may contribute to management of the operation of the time switch device.
Moreover, according to an aspect of the present invention, the time switch device has a modular architecture with physical and logical separation between a programming management module and at least one output management and driving module (also managing any input signals). The architecture of the time switch device is thus easily configurable and expandable.
Figure 1 schematically indicates with 1 a time switch device according to an embodiment of the present invention. The time switch device 1 has a casing 2, e.g. having a generally parallelepiped shape, with a longitudinal extension along an axis z having a front face 2a and a rear face 2b opposite to each other in a direction transverse to axis z, wherein the rear face 2b is designed to be coupled e.g. to an electrical control panel (not shown), for example through a DIN rail.
In the shown embodiment, the front face 2a of the casing carries a display 4 and input elements 5 including a cursor or joystick (in the embodiment shown, in addition or alternatively, keys and/or buttons) allowing a user to schedule an activation time and/or date.
The casing 2 further defines, for example at a corresponding upper portion (relative to axis z), a power supply input 6, formed by a first and a second input terminal 6a, 6b, designed to receive a supply voltage, e.g. from the power supply network; and, for example, at a corresponding lower portion (relative to the same axis z), a switching output 7, e.g. of the electromechanical relay type, consisting of at least a first, a second and a third exchange terminal 7a-7c (the relay being, e.g. of the exchange type); and an analogue output 8, in the example consisting of at least a first output terminal 8a referring to a reference terminal 9, to provide a first driving signal S₁, e.g. a pulse-width modulated voltage signal, and at least one second output terminal 8b, referring to the same reference terminal 9, to provide a second driving signal S₂, e.g. a DC voltage with a value comprised between 0 and 10 V.
In a manner non-shown, the casing 2 may further define a number of additional analogue outputs and/or a number of inputs, with input terminals designed to receive analogue or digital state signals or control signals from the outside, contributing to the management of the operation of the time switch device 1.
As schematically shown in Figure 2, according to an aspect of the present invention, the time switch device 1 comprises, in the casing 2, a first and at least a second electronic module 12, 14, electrically coupled by means of a connecting module 15, formed in a respective PCB (Printed Circuit Board) and respectively having a first and a second digital processing unit (not shown), for example including a microprocessor or microcontroller.
In a possible embodiment, the printed circuit boards of the first and second electronic modules 12, 14 are coupled inside the casing 2 at least partially overlapping each other, in a transverse direction with respect to axis z, for example, each being parallel to said front and rear faces 2a, 2b.
In particular, the first processing unit of the first electronic module 12 is designed to manage programming of the time switch device 1 and is also designed to control, according to the set programming, the second processing unit of the second electronic module 12, which is designed to manage the analogue and relay switching outputs of the time switch device 1.
In this embodiment, the first processing unit of the first processing module 12 therefore operates in a "master" mode and the second processing unit of the second processing module 14 therefore operates in "slave" mode.
In more detail, and as shown in Figure 3, the first electronic module 12, powered by the supply voltage V_al, in the example supplied by the power supply network at the power supply input 6, comprises:

the first processing unit, here indicated by 16, for example including a microprocessor, a microcontroller, or generally a CPU (Central Processing Unit) equipped with a non-volatile memory (not shown);
the display 4, controlled by the first processing unit 16, to display information (for example, a programming schedule);
the input elements 5, for example including a cursor or joystick, through which a user is able to make selections and input data for the first processing unit 16, particularly for programming the time switch device 1; and a wireless communication unit 18, for example of the NFC type (whose antenna 18' may conveniently be integrated into the printed circuit board of the first electronic module 12), operatively coupled to the first processing unit 16 configured to communicate with an electronic device, e.g. of a portable type, of the user, to receive programming data (in addition or alternatively to the use of said input elements 5), which can be conveniently stored by the first processing unit 16 in the associated non-volatile memory.

The second electronic module 14, in turn, comprises:

the second processing unit, here indicated by 20, for example including a microprocessor, microcontroller or CPU, provided with a respective non-volatile memory (not shown), and coupled to the first processing unit 16 through the connecting module 15;
a switching unit 22, including one or more switch elements, e.g. electromechanical relays, coupled to the second processing unit 20 (from which it receives suitable driving signals) and to the switching output 7;
a driving unit 24 coupled to the second processing unit 20 (from which it receives suitable control signals) and to the analogue output 8, and including analogue circuits providing a desired number of driving signals, including a first analogue circuit to generate the first driving signal S₁, of the PWM type, and a second analogue circuit to generate the second driving signal S₂, of the 0-10 V type;
- a buffer battery 25; and
- a supply unit 26, coupled to the connecting module 15 and to the buffer battery 25 and supplying an internal supply voltage V_cc to the second electronic module 14.

In the shown embodiment, the second electronic module 14 further comprises an input unit 26 coupled to the second processing unit 20 and to a number of analogue inputs, here indicated with INi, ... INj (e.g. for receiving state or control signals from the outside).
The connecting module 15 further comprises:

a first electrical connection 15a, which carries digital communication signals for the communication between the first and the second electronic modules 12, 14, and in particular a control signal S_c, sent by the first processing unit 16 to the second processing unit 20, as a function of which the outputs are controlled; and optionally a feedback signal S_r, sent by the second processing unit 20 to the first processing unit 16; and
a second electrical connection 15b, which carries a power supply signal S_al from the first electronic module 12 to the second electronic module 14, in particular to the power supply unit 26 of the second electronic module 14.

According to an aspect of the present invention, the second electrical connection 15b of the connecting module 15 is used to supply the second electronic module 14 only when the power is supplied by the power supply network, thus enabling a power saving of the buffer battery 25 (e.g. during the standby operation).
In an embodiment, the first and the second electrical connections 15a, 15b are each constituted by a single electrical wire, so that the connecting module 15 comprises a pair of electrical wires.
In use, the first processing unit 16 generates the control signal S_c to control the second electronic module 14 based on the programming imparted by the user through the input elements 5 and/or by communicating with the wireless communication unit 18, and, in addition or alternatively, according to the date and time dynamic calculation based on geographic location.
In particular, the control signal S_c received by the second processing unit 20 of the second electronic module 14 determines, at programmed and/or dynamically calculated times, activation of the switch elements of the switching unit 22 and/or generation of the driving signals S₁, S₂ by the driving unit 24.
The control signal S_c further determines the amplitude of the driving signals S₁, S₂, with variable analogue values ranging from 0% to 100% of a given maximum value (e.g. equal to the internal supply voltage V_cc).
In an embodiment, the driving signals S₁, S₂ are generated at the analogue output 8, in a simultaneous way, in order to activate simultaneous driving of multiple electrical loads.
In greater detail, the communication signals are exchanged between the first processing unit 16 of the first electronic module 12 and the second processing unit 20 of the second electronic module 14 according to a predetermined protocol that allows the use of the single electrical connection (first electrical connection 15a) provided by the connecting module 15.
In particular, the control signal S_c is sent from the first processing unit 16 to the second processing unit 20 asynchronously, at predetermined time intervals, for example of 1 s, as schematically shown in Figure 4.
The control signal S_c is encoded, e.g. by means of a serial encoding, to indicate the activation request of one or more switch elements of the switching unit 22 and the mode of generation of the driving signals S₁, S₂ by the driving unit 24 of the second electronic module 14.
A possible embodiment uses a Manchester serial encoding, which encodes the value of the single bits based on a level transition (from high to low or from low to high) of the digital signal.
The processing unit 20 of the second electronic module 16 samples the aforementioned control signal S_c with a suitable sampling period, e.g. equal to 1 µs.
According to an aspect of the present invention, the above protocol also envisages a re-calibration or synchronization, at each transmission cycle of the control signal S_c, of the time base adopted by the first and second processing units 16, 20, to compensate for any thermal and aging effects (in other words, the protocol provides a synchronization of the corresponding clocks).
For this purpose, at the start of each transmission cycle, a start sequence is sent, including the first two logical levels of the digital signal, indicated by L₁ and L₂ in Figure 4, and the duration of this start sequence is measured, duration which has a given design value, in the example of 400 µs.
Depending on the measured duration and on the possible deviation from the design value, the first and the second processing units 16, 20 can thus recalibrate their time base.
The subsequent levels of the digital signal (each having a predetermined duration, in the example of 400 µs), encode the logical, high or low, value of the digital signal bits. In the example shown in Figure 4, relating to control signal S_c, the digital signal has 8 bits; the logical value of each bit (bit0 - bit7), according to the Manchester encoding, is determined by the level transition type, e.g. '0' if the level transition is from low to high, and '1' if the level transition is from high to low (however, it is clear that different digital signal encodings can also be used).
The total duration of a transmission cycle is in the example of 7.2 ms.
As schematically shown in Figure 5, in a possible embodiment, the least significant bit (bit7) of the control signal S_c can indicate the activation (or not) of the electromechanical relay of the switching unit 22 (e.g., the logical value '1' indicates the activation of the relay). The remaining bits (bit0 - bit6) can indicate:

with values between 0 and 99, the percentage (comprised, indeed, between 0% and 99%) of the light intensity (dimming percentage) determined by the driving signals S₁ and S₂ generated by the driving unit 24, i.e. the amplitude of the driving signals S₁, S₂;
with the remaining values (in the example comprised between 100 and 128), the request of transmission of a suitable feedback signal S_r by the second processing unit 20 of the second electronic module 16 (each value may be associated to the indication of a different type of feedback signal S_r, for example for sending a signal indicating the state of a relay or of an external button, or the value of an analogue input).

If a feedback signal S_r is required, the protocol provides that such a signal, also digital and suitably encoded (e.g. by means of the aforementioned Manchester encoding), is transmitted through the same first electrical connection 15a, following the transmission of the control signal S_c. In particular, the feedback signal S_r may be sent from the second processing unit 20 to the first processing unit 16 at a given time interval after the end of the transmission cycle, e.g. with a duration of about 8 ms.
Advantageously, the above recalibration operation may also be performed at the start of the feedback signal S_r. According to an aspect of the present invention, the second processing unit 20 continuously decodes the instructions contained in the control signal S_c until a new valid instruction is received.
The second processing unit 20 internally generates a first reference frequency, e.g. equal to 15 kHz, which is used by the driving unit 24 for modulating the duty cycle for charging a capacitor at a suitable reference voltage, proportional to the analogue value of light intensity required by the first processing unit 16 (encoded by the control signal S_c) for generating the second driving signal S₂.
The second processing unit 20 further generates a second reference frequency as a sub-multiple of the first reference frequency, which is used by the same driving unit 24 to maintain a constant alignment between the first and the second driving signals S₁, S₂.
The repeatability of the frequency values is guaranteed by the recalibration performed at each transmission/reception cycle.
The advantages of the proposed solution clearly emerge from the previous description.
The time switch device 1 encloses in a single device (in single casing 2) both the electromechanical switch functions and the analogue driving functions, e.g. for generating driving signals to adjust the brightness of the associated lighting devices.
This gives significant advantages in terms of optimized resources and spaces, for example in the electrical control panel of a plant.
Moreover, the modular structure of the time switch device 1, providing a separation between the electronic programming module and the electronic driving module, advantageously allows an easy expansion of the functions of the time switch device, e.g. by generating further driving signals and/or by introducing further electromechanical switch elements.
The presence of the switching unit 22 also allows an autonomous management of the supply of electrical loads that require power supply voltages comprised between 1 and 10 V, allowing selective switching off of the loads by interrupting the power supply (the minimum value of the analogue driving output, equal to 10%, might not fully extinguish the load).
Finally, it is clear that modifications and variations with respect to what herein described and shown may be carried out without departing from the scope of the present invention as defined in the appended claims.
In particular, it is clear that the number of switch elements in the switching unit 22, as well as the number and type of driving signals generated by the drive unit 24, may vary from those illustrated by way of example. Moreover, it is clear that the encoding used for the signals exchanged between the first and the second processing units 12, 14 may also vary.
In general, this solution could include the presence of further electronic modules in the time switch device 1, e.g. for driving additional electrical loads and/or for activating additional switch elements; the respective processing units of such further modules would, in a manner equivalent to what has been previously discussed, be coupled in slave mode to the first processing unit 16 of the first electronic module 12 (managing the programming of the time switch device 1 and its operation).

Claims

A time switch device (1) comprising:
a casing (2);

a first electronic module (12) having a first processing unit (16) configured to manage a programming of the time switch device (1); and

a second electronic module (14), distinct from the first electronic module (12) and housed in the casing (2) together with the first electronic module (12), having: a second processing unit (20), communicatively coupled to the first processing unit (16); a switching unit (22), comprising at least one switch element, coupled to the second processing unit (20) and to a switching output (7) of said time switch device (1); and

a driving unit (24), coupled to the second processing unit (20) and to a driving output (8) of the time switch device (1), comprising analogue circuits designed to provide a number of driving signals (S₁, S₂),

wherein said first processing unit (16) is designed to generate, based on said programming, a control signal (S_c) for said second processing unit (20), and said second processing unit (20) is designed to manage the selective activation of said at least one switch element and the generation of said driving signals (S₁, S₂) based on said control signal (S_c),

said control signal (S_c) being a digital signal encoding control information for the selective activation of said at least one switch element and the generation of said driving signals (S₁, S₂).
The device according to claim 1, further comprising a connecting module (15), which electrically couples said first electronic module (12) to said second electronic module (14) and comprises a first electrical connection (15a) for transferring said control signal (S_c) from said first processing unit (16) to said second processing unit (20) .
The device according to claim 2, wherein said first electrical connection (15a) includes a single electrical wire and said control signal (S_c) is transferred by a serial transmission.
The device according to claim 2 or 3, wherein transfer of said control signal (S_c) from the first processing unit (16) to the second processing unit (20) is carried out by means of a transmission protocol involving transmission cycles repeated at a predetermined interval; wherein, at each transmission cycle, the protocol involves a synchronization operation for the synchronization of a time base of said first processing unit (16) and of said second processing unit (20).
The device according to claim 4, wherein said synchronization operation envisages said first processing unit (16) transmitting a start sequence for an interval with a predetermined duration; and wherein said second processing unit (20) is designed to measure the duration of said interval and synchronize its time base based on the difference between the measured duration and the predetermined duration.
The device according to claim 4 or 5, wherein said transmission protocol involves, between consecutive transmission cycles, the transmission of a feedback signal (S_r) from said second processing unit (20) to said first processing unit (16).
The device according to claim 6, wherein said second electronic module (14) further comprises an input unit (26), coupled to the second processing unit (20) and to a number of analogue inputs (INi, INj), which are designed to receive status signals from the outside; and wherein said feedback signal (S_r) is generated also based on said status signals received from the outside.
The device according to any one of claims 2-7, wherein said connecting module (15) further comprises a second electrical connection (15b) for transferring a power supply signal (S_a) from said first electronic module (12) to said second electronic module (14); wherein said second electrical connection (15b) includes a respective single electrical wire.
The device according to claim 8, wherein said second electronic module (25) further comprises a buffer battery (25) and a power supply unit (26) coupled to said buffer battery (25) and to said second electrical connection (15b) in order to receive said power supply signal (S_al); wherein said power supply unit (26) is configured to generate an internal supply voltage (V_cc) for said second processing module (14).
The device according to any one of the preceding claims, wherein said driving unit (24) is designed to jointly provide at said analogue driving output (8): at least a first driving signal (S₁) being a DC voltage signal ranging from a minimum voltage value to a maximum voltage value; and a pulse-width modulated voltage signal.
The device according to claim 10, wherein said driving unit (24) is designed to adjust an amplitude of said first (S₁) and second (S₂) driving signals based on said control signal (S_c).
The device according to any one of the preceding claims, wherein said first processing unit (16) is designed to cooperate with programming-data input elements (5, 18) for managing said programming; said programming-data input elements comprising at least one input element (5) coupled to said casing (2) and/or a wireless communication module (18), which is designed to be coupled to an external device for receiving said programming data.
The device according to any one of the preceding claims, wherein the switch element of said switching unit (22) includes at least one electromechanical relay.
The device according to any of the preceding claims, wherein said first (12) and second (14) electronic modules are provided in respective printed circuit boards, which are physically distinct from one another and are stackedly arranged inside said casing (2).