Communication and coding system for controlling electrical actuators

Abstract: A communication and coding system (SC) for controlling electrical actuators (A), in which at least one remote command device (D, E, S, U) is able to control the actuators (A) and the connected electrical loads (L) via a single conductor (CP) which directly connects together the output of the remote command device (D, E, S, U) and the specific command inputs (P) of each actuator (A). This ensures high versatility of controllable electrical and/or electronic functions, while at the same time allowing various remote command devices (D, E, S, U) of different types to be connected to one and the same conductor (CP) and to a single actuator (A).

Description: This invention relates to a communication and coding system for controlling electrical actuators. Electrical actuation members are currently controlled by remote command devices in various ways: by feeding a simple electrical signal to the load, as in the case of relays; by applying a phase signal to the appropriate input by a pushbutton, as in the case of lighting dimmers; or finally by using serial lines conveying digital signals, as in the case of particularly advanced actuators, which can also be connected to digital command buses. Each currently used control method however presents drawbacks and disadvantages for installers and final users. The most simple methods from the electrical viewpoint, ie controlling by a state signal or the temporary application of a phase signal by means of a pushbutton, do not allow large versatility in controllable functions, which remain limited to load switch-on and switch-off, or possibly dimmer adjustment for lighting devices. Other methods involve feeding the electrical actuator with variable voltages or currents, which provide information regarding load switch-on or switch-off and offer the possibility of adjustment to intermediate control values, proportional to the fed voltage or current. In particular, a signalling system in which electrical actuation members are controlled by means of remote command devices by feeding electrical actuators with variable voltages, according to the preamble of present claim 1, is known from GB-A-2 197 568. These method have however the drawback of not enabling (or at least only with great difficulty) several command devices to be used, positioned in parallel and connected to the same actuator. The most complex methods, which also involve serial communication between control circuits and the electrical actuator, are reliable and can comprise many control devices connectable to a single actuator, but are extremely costly. Hence, in none of the aforesaid cases used up to the present time is it possible to connect to one and the same actuator a multiplicity of different-type command devices of circuit complexity proportional to the functions to be performed, in a simple and economical manner. An object of the present invention is to solve the aforesaid problems by defining in particular a communication and coding system for controlling electrical actuators, which provides high versatility of controllable electrical and electronic functions, while at the same time allowing various remote command devices of different types to be connected to one and the same conductor and to a single actuator. A further object of the invention is to provide a communication and coding system which can also be installed within traditional circuit systems and arrangements, without involving considerable work or modification. A further object of the present invention is to define a communication and coding system which can be implemented without the use of complex electrical and electronic technology and/or costly materials. These objects are attained by a communication and coding system for controlling electrical actuators in accordance with claim 1, to which reference should be made for brevity. Advantageously, the system of the invention comprises at least one actuator, connected to a constant-frequency electrical mains supply and to a series of controlled electrical loads, such as incandescent lamps, each provided with a specific command input. The electrical actuators are provided internally with microcontrollers or state machines able to interpret the signals reaching the command input in accordance with predefined coding, for the purpose of translating them into specific actions on electrical loads controlled by them. The system therefore comprises an assembly of different-type remote command devices traversed by a phase signal of the electrical mains supply and are each provided with a specific control output, and finally a single-wire electrical conductor which directly connects remote command device outputs and actuator inputs together; in the absence of commands, this conductor is in its rest condition. Further characteristics and advantages of the invention will be more apparent from the description of a preferred but not exclusive embodiment of the communication and coding system of the invention, illustrated by way of non-limiting example on the accompanying schematic drawings, in which: Figure 1 is a block diagram of the communication and coding system for controlling electrical actuators, according to the present invention; Figure 2 is a cartesian graph showing the time-variation of the voltage relative to a load switch-on or switch-off signal fed by a first remote command device of the communication and coding system, according to the present invention; Figure 3 is a cartesian graph showing the time-variation of the voltage relative to a load brightness adjustment signal fed by the remote command device of Figure 2, according to the present invention; Figure 4 is a cartesian graph showing the time-variation of the voltage relative to a load switch-on signal, followed by a brightness adjustment signal and by a load switch-off signal, which are fed by the remote command device of Figure 2, according to the present invention; Figure 5 is a cartesian graph showing the time-variation of the voltage relative to a load switch-on or switch-off signal fed by a second remote command device of the communication and coding system, according to the present invention; Figure 6 is a cartesian graph showing the time-variation of the voltage relative to a load adjustment signal fed by the remote command device of Figure 5, according to the present invention; Figure 7 and Figure 8 are two cartesian graphs showing examples of the time-variation of signals comprising load switch-on, adjustment and switch-off functions, which are fed by a third remote command device of the communication and coding system, according to the present invention; Figure 9 is a partial block diagram of a modification of the communication and coding system, according to the present invention. With reference in particular to Figures 1 and 9, SC indicates overall the communication and coding system for controlling electrical actuators A, according to the present invention, AL indicates an electrical mains supply of sinusoidal voltage and constant frequency, for example a 230 V mains supply, N indicates the neutral conductor of the mains AL, L indicates the controlled electric loads, for example incandescent lamps, each provided with an electrical actuator A with a specific command input P, and finally ALR indicates an electrical conductor which transmits the command signal from the actuator A to the corresponding load L. D, E, S, U indicate four particular remote command devices, connected to the phase conductor of the electrical mains supply AL and provided with a command output for the actuators A. Specifically, D indicates a knob command device with double movement, in which pressing the accompanying button determines switch-on, switch-off and memorization of the brightness values set for the lamps L, whereas rotating the knob adjusts the brightness of the lamps L; E indicates a pushbutton command device to interrupt or feed an electrical signal to the actuators A; S indicates a sensor device (for brightness, presence or other); and U indicates an interface able to receive commands from a digital communication bus BU to then convert them into an electrical command to feed to the actuators A. Finally, CP indicates a control conductor which directly connects together the outputs of the remote command devices D, E, S, U, and the command inputs P of the actuators A; in the absence of commands, the control conductor CP is in its rest condition. With particular reference to Figures 2, 3, 4, 5, 6, 7 and 8, V, W along the vertical axis of the cartesian graphs indicate voltage and power signals respectively, T along the horizontal axis of the cartesian graphs indicates time, and T1, T2, T3, T4, T5 indicate particular time periods along the horizontal axis of the various graphs. We shall now examine in detail the operation of the various remote command devices D, E, S, U, together with the type of coding of the commands which they are able to feed to the actuators A, in a particular embodiment of the invention described by way of non-limiting example, in which said remote command devices D, E, S, U behave as dimmers for load lamps L. The pushbutton command device E can feed a switch-on or switch-off command and an adjustment command to the load lamps L via the actuators A. The switch-on or switch-off command is fed by pressing the pushbutton E. The pushbutton E is pressed for a time less than a predefined limiting time value T5. This connects the control conductor CP to the phase of the sinusoidal mains AL voltage, with feed of a corresponding limited number of complete sine waves at mains AL frequency to the command input P of the actuators A. The load lamps L are powered or extinguished cyclically at each pressing of the pushbutton E. The command for adjusting the brightness of the lamps L is achieved by pressing the pushbutton E for a time exceeding the predefined limiting value T5, to feed whole sine waves at mains AL frequency to the input P of the actuators A. This is sensed by the actuators A, which power the lamps L via the conductor ALR whatever the preceding state, and enter the adjustment cycle to increase and decrease the brightness of the load lamps L. The desired brightness value is maintained by the actuator A the moment in which the pushbutton E is released. A switch-off operation follower by a switch-on operation restores the last brightness value set by the adjustment cycle. The knob command device D can also feed switch-on or switch-off and adjustment commands. In a manner similar to the pushbutton command device E, switch-on and switch-off are achieved by axially pressing the knob D for a time less than the predetermined time T5. Applying along the control conductor CD a train of whole sine waves, half-waves or parts thereof taken from the electrical mains supply AL and continuing for a time less than the predetermined time T5 causes load switch-off if previously switched on and switch-on if previously switched off. In contrast, applying along the control conductor CD a train of whole sine waves, half-waves or parts thereof continuously for a time exceeding the time T5 activates a cycle of adjustment of the electrical power W fed to the load, such that said electrical power W is proportional to the time for which the wave train is maintained. The electrical power W reaches an extreme value and remains defined until the next application of wave trains taken from the mains AL. Alternatively the direction of adjustment can be reversed by persisting with the wave train. The brightness level of the lamps L, operated by the actuators A, is the last brightness level set by any one command device D, E, S, U of those provided in the communication and coding system SC of the present invention. Load brightness adjustment is hence effected by rotating the knob D, which is proportional to the brightness value desired. When this value has been reached, the knob D is pressed for a time exceeding the predefined limiting value T5, so as to feed to the command inputs P of the actuator A, for the entire pressing time, a periodic signal of particular form (examples in this sense are shown in Figures 6, 7, 8), taken from the sinusoidal voltage signal (shown in Figure 5) withdrawable from the electrical mains supply AL, in which the form of an individual half-wave is divided into three time periods T1, T2, T3, in the third time period T3 there being contained a fourth time period T4 of conduction of the signal along the conductor CP, and proportional to the angular position of the knob D. Alternatively, the knob D can be pressed to power the load lamps L, after which the adjustment is made by rotating the knob D, while simultaneously pressing. If the form of an individual component half-wave of the command train is divided into three time periods T1, T2, T3 (as stated heretofore), in which during the first time period T1 there is signal conduction along the conductor CP, during the second time period T2 there is no conduction, and the third time period T3 contains a conduction period T4, the electrical power W fed to the load is proportional to the ratio of the time periods T4 and T3 respectively. The desired brightness value of the load lamps L is therefore proportional to the angle of rotation of the knob D about its axis. Different angles of the knob D result in a like variation in the duration of conduction of an individual half-wave (component of the command wave train), which corresponds to the time period T4 of the signal of Figure 8. The interface U, which is connected to a digital communication bus BU, can feed the actuator A, via the control conductor CP, with all the aforedescribed signals, following commands originating from the digital bus BU. It can also set the actuator A to desired brightness values for the load L by simulating an adjustment procedure, ie maintaining for a time exceeding the prefixed limiting value T5 that half-wave of the signal of Figure 5 corresponding to the time period T3 in a manner proportional to the brightness value required for the load lamp L. The sensor device S can be of. various types, for example it can be a presence or darkness sensor. The command fed along the control conductor CP by the sensor S can be a switch-on command for the load lamp L, followed by a switch-off command on reaching a given condition (a predetermined time, a required brightness level, for example, for self-adjustment, etc.). Finally the remote command devices D, E, S, U can be represented by a regulated output of a first actuator A which, via a control conductor CP, is returned to the input of a second actuator A2 of the system SC, in accordance with the connection diagram of Figure 9. In this case, the electrical actuator A2 enters into self-adjustment, by positioning itself at the brightness level present along the conductor ALR leaving the actuator A, consequent on switching-off and switching-on the load lamps L. The application of a voltage signal dependent on the electrical output power WS of each actuator A to the control conductor CP causes an electrical power value W to be fed to the load L connected to the actuator A2 which is proportional to the level sensed along the electrical conductor ALR leaving the actuator A. From the aforegoing description, the characteristics of the communication and coding system for controlling electrical actuators according to the present invention are evident, as are its advantages. In particular, these are represented by: considerable versatility of controllable functions, because of the multiplicity of signals applicable to the control conductor and the variety of types of devices within the actuators, able to reconstruct the desired behaviour from the input signals; maintenance of the traditional configuration in parallel with the remote command devices, resulting in the possibility of connecting command devices of different type to the same control conductor, provided these are of the scheduled types (it is hence possible to use both a pushbutton connected to the phase of the electrical mains supply and a knob command device, a sensor or an interface for connection to digital communication buses for activating the same actuator); possibility of positioning several actuators in parallel, while at the same time ensuring functional balance (all switched on or off simultaneously, or all under adjustment at the same percentage); extremely low cost of the remote command devices, such as the phase-connected pushbutton; possibility of easily connecting several actuators in a master/slave configuration, in which only the master actuator is connected to the control conductor; possibility of using the communication and coding system of the present invention in traditional-method electrical installations and systems (for example comprising dimmers and adjustment pushbuttons). It is apparent that numerous modifications can be made by an expert of the art to the communication and coding system of the present invention, but without leaving the scope of protection of the inventive idea, that in the practical implementation of the invention the forms of the illustrated details can be different, and that these can be replaced by technically equivalent elements.

Claims: Communication and coding system (SC) for controlling electrical actuators (A), which is connected to an electrical mains supply (AL) of sinusoidal voltage feeding at least one remote command device (D, E, S, U), said system (SC) comprising at least one electrical load element (L), in which electrical power (W) is dissipated and to which at least one neutral conductor (N) of the mains supply (AL) and at least one means (ALR) for electrical connection to each of said actuators (A) are connected, said command device (D, E, S, U) and said actuator (A) each being provided with a specific command input (P) and a specific command output and further being connected to the phase of said mains supply (AL) and being connected together by an electrical control conductor (CP), which collects electrical signals from said command device (D, E, S, U) and controls said load element (L), via said actuator (A), in accordance with an electronic coding for feeding, interrupting and adjusting electrical power (W), which is transmitted through said load element (L), and for interpreting and communicating electrical signals collected from said command device (D, E, S, U), whereby said electronic coding consists of feeding along said control conductor (CP) a train of sinusoidal half-waves, each half-waves varying with time and said variation being divisible into three portions, of which a first portion corresponds to a first time period (T1) during which said command device (D, E, S, U) is actuated so that the control conductor (CP) is held at the voltage of the electrical mains supply (AL), a second portion corresponds to a second time period (T2) during which said command device (D, E, S, U) is actuated so that the control conductor (CP) is held at zero voltage, and a third portion corresponds to a third time period (T3), which contains a fourth time period (T4), whereby the control conductor (CP) is held at the voltage of the electrical mains supply (AL) during the fourth time period (T4) and held at zero voltage during the rest of the third time period (T3), characterised in that said remote command devices (D, E, S, U) consist of at least one pushbutton (E), at least one control and adjustment knob (D), at least one interface (U) for connection to a digital communication bus (BU) and at least one sensor device (S), said control and adjustment knob (D) having a rotary movement and an axial movement, so that, on pressing said knob (D) in an axial direction, a periodic voltage signal, obtained from the voltage signal of said mains supply (AL), is fed along said control conductor (CP), said periodic voltage signal comprising a train of sinusoidal half-waves, each half-waves varying with time and said variation being divisible into three portions, of which a first portion corresponds to said first time period (T1) during which said control conductor (CP) is held at the voltage of the electrical mains supply (AL), a second portion corresponds to said second time period (T2) during which said control conductor (CP) is held at zero voltage, and a third portion corresponds to said third time period (T3), which contains said fourth time period (T4), whereby the control conductor (CP) is held at the voltage of the electrical mains supply (AL) during said fourth time period (T4) and held at zero voltage during the rest of said third time period (T3), said fourth time period (T4) and the ratio of said fourth time period (T4) to said third time period (T3) being proportional to the angular position of said knob (D) about its axis of rotation, said electrical power (W), which is transmitted through said load element (L), also being proportional to said ratio of the fourth time period (T4) to the third time period (T3). Communication and coding system (SC) as claimed in claim 1, characterised in that said sensor device (S) is a brightness/darkness sensor or a presence sensor. Communication and coding system (SC) as claimed in claim 1, characterised in that said periodic voltage signal is fed along said control conductor (CP) for a period of time less than a prefixed time period (T5), so that said electrical load elements (L) are not operating if they are previously operating and, vice-versa, said electrical load elements (L) are operating if they are previously not operating, said electronic coding further being such that the application of a train of whole waves or half-waves continuing for a time exceeding said prefixed time period (T5) activates a cycle of adjustment of the electrical power (W) fed to the load (L), so that said power (W) is proportional to the time for which said wave train is maintained, to reach an extreme value and remain defined thereat until a next wave train application or. the direction of adjustment is reversed by persisting with said wave train. Communication and coding system (SC) as claimed in claim 1, characterised in that said electronic coding is managed so as to fed into said control conductor (CP) a voltage signal, which drops at the output of a first actuator (A) of said electrical actuators, causing an electrical power value, which is proportional to the output power (W) of said first actuator (A), to be fed to one of said load elements (L), connected to a second actuator (A2) of said electrical actuators, thus obtaining automatic self-adjustment of said second actuator (A2), which becomes positioned at corresponding levels of electrical power (W) deliverable with respect to said first actuator (A), relative to the maximum deliverable by each of said actuators. Communication and coding system (SC) as claimed in claim 1, characterised in that each of said load elements (L) is constituted by an incandescent lamp, which is operating when electrical power (W) is fed, and is not operating when electrical power (W) transmission is interrupted.

Inventors: SANTINI ERNESTO, SANTINI, ERNESTO
Applicants: BTICINO SPA, BTICINO S.P.A.
Application year: 1997
Main classification: H05B37
IPC codes: H02J13, H05B37