FR2756683A1 - Touch two=way switch and current control of single phase ac lighting - Google Patents

Abstract

The control has two-way switches in series with the a.c. source and the equipment (2) and the means (C) to adjust the fraction of the half-cycle of the supply (V) applied to the equipment. The detector (FR) responds when the impedance (Zf) associated with the touch control is very high or when it is very small. The processing (FC) of the supply is prior to the phase control (100) so that the latter is immune to all interference from the supply. The voltage regulation (17) of the phase control is a zener diode whose current is greater than the recommended current to allow for a sensitive control operation.The touch control itself has an extended conducting region (27), separated from the lamp supply cable (29) by an insulated layer (28).

Description

', TOUCH CONTROL METHOD AND DEVICE, AND
APPLICATION TO LIGHTING EQUIPMENT "
The present invention relates to a touch control method. It also relates to a touch control device implementing this method, as well as applications of this method to lighting equipment.

 The adjustment of the light intensity of lighting equipment by touch control devices is now widely known, as illustrated for example by document GB-A-2 249 378. In most of the equipment proposed, the area of touch control is limited in area, for example a conductive patch, the base of a bedside lamp or the metal structure of a lampshade. Also known from document FR-A-2 701 792 are luminaires in which the tactile contact zone consists of all or part of the external surface of the support of these luminaires, this support being previously subjected to an impregnation treatment in order to make it conductive.

 Most touch-sensitive light equipment also have in common the use of a triac, a widely used electronic component of power, for applying a form d to a resistive and / or inductive load, in particular a bulb or a tube. voltage wave corresponding to an adjustable fraction of the half-arcs of the sinusoidal waveform of the mains voltage. This triac is controlled by an electronic circuit directly connected to the mains and designed around a specialized integrated triac control circuit, such as the SLB 0587 circuit from SIEMENS.

 This specialized circuit provides a triac control particularly suitable for the adjustment of lighting equipment. It is widely used in an electronic circuit structure recommended by the manufacturer. This circuit is in fact typically suitable for applications in which the sensitive or contact zone is only located a few centimeters from the circuit itself, for example for a sensitive wall switch. These are applications which can be referred to as direct sensory contact.

 However, it has been noted by the present applicant that the application of the circuit recommended by the manufacturer of the SLB 0587 circuit to luminaires provided with tactile zones distant from the phase control circuit could lead in certain situations and configurations to reliability problems. and lack of performance due to the fact that the sensitive zone can be more than one meter from the circuit and that the contact is transmitted by the structure of the device and not by an electric wire. In addition, for luminaires having a large contact surface, it has been found experimentally to be highly sensitive to radiated or conducted electromagnetic disturbances which can lead to nuisance tripping. In addition, the current electronic touch control circuits are sometimes sensitive to disturbances carried out on the sector.

 The object of the present invention is to remedy these drawbacks by proposing a tactile control method which is suitable for the use of large or remote tactile zones by presenting better immunity to electromagnetic disturbances.

 This is obtained with a tactile control method, for controlling the supply of electrical equipment, in particular lighting equipment, from a single-phase alternating voltage source, comprising a phase control for applying an adjustable fraction of each half-cycle of the AC voltage source on said electrical equipment, this phase control depending on a detection of leakage current between a tactile zone located near an electrically conductive zone or itself electrically conductive and a reference neutral associated with said voltage source when a user puts a part of his body, in particular one or more fingers, in contact with said electrically conductive touch zone.

 According to the invention, the leakage current detection comprises a processing upstream of a leakage current signal sampled at a point of said electrically conductive area, to discriminate any non-tactile signal, in particular any signal induced on said electrically conductive area. by external disturbances.

 As will be seen below, this discrimination function supposes not only filtering of the parasitic signals not resulting from a tactile action but also a high level of sensitivity in order to be able to detect leakage currents coming from distant or large tactile zones. dimension.

 The merit of this invention resides in particular in the fact that it makes it possible to take into account much larger contact surfaces than those currently admissible with current touch control methods.

The touch zone can take many forms and be made from various types of material of variable conductivity, which can range from electrical insulation to metallic conductor. By way of nonlimiting examples, there may be mentioned:
- one or more layers of paint or varnish up to a thickness of the order of mm,
- special coatings or treatments, or
- wooden cladding.

 It suffices to provide insulation between the tactile zone and the seat of the electrical equipment which has a very high impedance in front of the leakage impedance of the tactile zone. The conductive zone located near the tactile zone is preferably made from a material which is a good electrical conductor, for example a metallic material, a porous material charged with metallic particles or else an insulating material such as terracotta or the ceramic on which has been deposited, by brush or by spraying, a layer of an electrical conductive product, for example based on carbon or any other conductive product. It is also conceivable that the touch zone is constituted by enamels produced on terracotta and is at the same time considered as a conductive zone.

 In a preferred version of the invention, the touch control method further comprises upstream processing of the single-phase alternating source voltage to limit any overvoltage liable to induce untimely phase controls.

 The touch control method according to the invention preferably further comprises an increase in the leakage current flowing through the touch zone and the conductive zone, compared to the level of follow-on current which would be obtained with a current touch control method. Furthermore, the processing of the leakage current signal is adapted to provide touch control detection over a wide range of leakage impedance.

According to another aspect of the invention, a device is proposed for controlling in touch mode the supply of electrical equipment, in particular lighting equipment, from a single-phase alternating voltage source, comprising:
- bidirectional switch means controlled to generate adjustable fractions of half-cycles of supply voltage from the single-phase alternating voltage source,
means for phase-controlling said two-way switch means, in particular on the basis of a leakage current signal between an electric touch zone near an electrically conductive zone or itself electrically conductive and a neutral reference associated with said single-phase alternating voltage source, this leakage current being generated when a user puts part of his body in contact with said tactile zone, this device implementing the method according to the invention.

 According to the invention, the device is characterized in that it further comprises means for processing the leakage current signal sampled at a point in the conductive area so as to discriminate any signal induced on said tactile area by external disturbances .

 In a preferred embodiment of the invention, the means for processing the leakage current signal are arranged to provide leakage current detection when the leakage impedance associated with the control contact is of very high module.

 It is also advantageously possible to provide that the means for processing the leakage current signal are further arranged to provide leakage current detection when the leakage impedance associated with the control contact is of very low modulus.

 It is also preferable to provide that the means for processing the leakage current signal are arranged to obtain an increase in the intensity of the leakage current.

 In a preferred embodiment of a touch control device according to the invention, this further comprises means for processing the single-phase alternating voltage upstream of the phase control means so that the phase control means are substantially immune to any disturbance conducted from the single-phase alternating voltage source.

Other features and advantages of the invention will appear in the description below. In the appended drawings given by way of nonlimiting examples:
- Figure 1 illustrates in the form of block diagrams
the essential functions of a
touch control according to the invention; and
- Figure 2 illustrates a practical example of a circuit
electronic implemented in a device
touch control according to the invention designed around the
Siemens SLB 0587 circuit.

 We will now describe the essential functions and modules of a touch control device according to the invention, together with the associated control method, with reference to the aforementioned figures. In the following, we will designate by the same reference elements or components common to the two figures.

 We consider lighting equipment 1 comprising a luminaire 2 comprising for example a base 21, a tubular structure 24 at least partially metallic, a module 26 for receiving an incandescent or halogen light bulb 22, and an electronic dimmer integrating a device for touch control 10 according to the invention. The tubular structure 24 has on at least part of its external surface a tactile zone 20 made from a material 28, for example paint or varnish in one or more layers, and covering an electrically conductive zone 27 produced by example in the form of a metal tube in which an electrical cable 29 for supplying the bulb 22 is passed in particular, or in the form of a layer of an electrically conductive material deposited on a structure made of insulating material ( for example terracotta) or poorly conductive.

 The touch zone 20 is necessarily isolated, for example by an insulating part 25, from the base 21 if the latter is conductive and from the surface 40 on which the luminaire 2 is placed. The level of electrical insulation which the part must have insulator 25 depends directly on the electrical conductivity of the material constituting the tactile zone and on the dimensions of the latter.

 The touch control device 100 comprises a control part C and a power part P comprising a triac 15 acting as a controlled bidirectional switch and controlling the electrical supply of the bulb 22 from a single-phase alternating voltage source V which is generally the sector, via a transformer 14. A circuit FC of the alternating input voltage is arranged upstream of the triac 15 to protect the touch control device 100 from any untimely control due to a disturbance in the sector.

 The control part C is built around a phase control circuit 100, in practice a specialized integrated circuit such as the SLB 0587 circuit from SIEMENS or an equivalent circuit, receiving a leakage current signal coming from the touch zone 20 through a discrimination circuit FR connected to the conductive area 27 and emitting a signal T for triac tripping 15.

The leakage current signal previously processed by the discrimination circuit FR is applied to input 5 and subjected to an input control IC, then to an evaluation and recognition of signal SE and applied to the input of a phase locked loop. PLL (Phase Loop
Lock). This phase locked loop is coupled to a synchronization module SC connected via an input 4 to the power part P to take an image of the voltage across the terminals of the triac 15, and is connected to an external integrator circuit RC via the pins 3 and 7 of the integrated circuit 100. The phase locked loop ensures the synchronization of the triac trigger pulses 15 on the AC voltage signal, and supplies clock signals CK to a safety blocking module ST, to a timer control logic CL, to the evaluation and recognition module SE, to a counter SC for storing the lighting setpoint and to a comparator module CO. The phase control circuit 100 furthermore comprises a logic for triggering pulse output TP and an output stage OS delivering at output 8 the trigger pulses T, and is provided with a circuit VS for supplying from the mains voltage a rectified supply voltage at input 7 with respect to a ground reference 1.

A practical embodiment of a touch control device 10 according to the invention is illustrated in FIG. 2. The discrimination circuit FR is here produced in the form of two capacitors Csl, Cs2 (1 nF, 2 kV) in series with paralleling a resistance
Rp (4.7 MS) and a capacitor Cp (10 nF). The resistor 12 disposed between the phase line Ph and the detection input 5 is preferably determined as a function of each type of luminaire controlled. As a practical example, the resistance 12 is chosen from a range of 100 kQ to 800 kQ, therefore at values significantly lower than the values recommended by the manufacturer, namely from 1 MQ to 4.7 Mn. The use of a resistor 12 of lower value made it possible to obtain a satisfactory detection sensitivity in control situations where the tactile zone is of large dimension, the values recommended by the manufacturer being in fact adapted to uses of control by sensitive button.

 The presence of the capacitor Cp in parallel on the resistor Rp has the effect of increasing the intensity of the leakage current while not affecting its active component. This classic effect due to the capacitive phase shift provided by the capacitor is used here to obtain greater sensitivity of the touch control device according to the invention. Furthermore, the capacitors Csl, Cs2 connected in series contribute to reinforcing the safety of the user.

The supply circuit VS adopted in the touch control device according to the invention differs from that recommended by the manufacturer in that one of the filtering capacitors 16 is chosen at a value (68 pF) significantly lower than those recommended by the manufacturer, namely between 10 and 100 nF. This choice made it possible to considerably strengthen the immunity of the phase control circuit to HF disturbances carried out on the sector by eliminating numerous untimely control situations. It should also be noted that it is necessary to provide a Zener diode 17 for regulating the supply voltage of the phase control circuit which is oversized in current compared to the manufacturer's recommendations for operation in sensitive control, in order to guarantee satisfactory operation of the touch control device 10 according to the invention. As a practical example, a reference Zener diode has been used here.
BZX85C.

 Furthermore, in certain specific applications of the touch control device according to the invention, it may be advantageous to place a resistor 18 between the phase line and the anode of the Zener diode 17, in order to further increase the detection sensitivity. without deteriorating the reliability of the device. This resistor 18, which can for example be chosen to be equal to 680 kQ, has in particular the effect of discharging the capacitor 19 from the supply circuit VS and therefore of avoiding a voltage drift across the terminals of this capacitor.

 In addition to the HF 13 filtering circuit recommended by the manufacturer, there is provided upstream of the phase control circuit 100 an FC circuit for processing the input voltage which can be embodied in its simplest embodiment by a varistor which has a very high resistance as long as the voltage across its terminals remains below a threshold voltage, this resistance collapsing beyond this threshold voltage.

 We will now describe the operation of the touch control device according to the invention.

 When a user 30 puts one or more of his fingers 32, or another part of his body, in contact at any point in the tactile zone 20 of the luminaire 2, a leakage current then flows between the phase of the sector and the neutral N through the discrimination circuit FR, the conductive area 27, the material 28 constituting the tactile area 20, the finger (s) 32, the user's hand and body 30, and the ground. The various conductive components external to the tactile control device 10 can be modeled by a leakage impedance Zf, the module of which varies considerably depending on the location where the luminaire 2 is placed, in particular the wet or dry nature of the ground, the type of shoes. worn by the user and other environmental factors.

 The leakage current If is then detected and processed by the phase control circuit, for example the circuit SLB 0587, which generates triac tripping pulses T 15 by adjusting the angle or the tripping phase as a function of the duration of the contact 32 exerted on the tactile zone 20.

The phase control circuits, for example, the SLB 0587 circuit, are generally designed to memorize the extinction level and restore it on ignition if a pin (2) is left free. When this pin is brought to a high level, the lighting is then carried out at the maximum level, corresponding to a phase angle on ignition of 1520. The touch zone is connected to the input pin 5 of the SLB 0587 circuit. through the discrimination circuit FR and one or more resistors of several MQs which have the function of protecting the user. Furthermore, other protection components are provided within the touch control device according to the invention, such as a diode
Clipping zener and a diode limiting the applied direct voltage.

 The passage from ignition to extinction and from extinction to ignition is effected by a short touch, of duration between 50 and 400 milliseconds.

The light intensity is adjusted by touching it for more than 400 milliseconds. The variation of the phase angle, and therefore of the illumination, is quasi-linear as a function of time until maximum illumination. The return to a minimum illumination is obtained by respecting a contactless period of time and then by exercising sufficient level contact.

 The implementation of the tactile control device according to the invention has made it possible in practice to operate reliably in a voltage range of 150 to 270 Volts, for conditions of use ranging from a state of high insulation (user on a base in plastic material at least ten centimeters thick) in a state of high conduction (wet ground).

 The present invention can advantageously be applied for the tactile control of at least partially metallic luminaires such as floor lamps, table lamps, wall lights, etc.

 Of course, the invention is not limited to the examples which have just been described and numerous modifications can be made to these examples without departing from the scope of the invention. Thus, the shape and the size of the tactile zones can be arbitrary. It is the same for the materials constituting respectively the tactile zone and the conductive zone for which the choice will be conditioned inter alia by considerations of electrical conductivity, esthetics and feasibility.

 Furthermore, it is possible to envisage other triac control circuit structures than the SLB 0587 circuit described above. In addition, the present invention can also be implemented for controlling the supply of electrical equipment other than lighting equipment, for example for controlling small electric motors.

Claims (14)

 1. A tactile control method for controlling the supply of electrical equipment (2), in particular lighting equipment, from a single-phase alternating voltage source (V), comprising a phase control for applying a adjustable fraction of each half-cycle of the alternating voltage source (V) on said electrical equipment (2), this phase control depending on a detection of leakage current (If) between a tactile zone (20) located nearby of an electrically conductive area (27) or itself electrically conductive and a neutral reference (N) associated with said voltage source (V) when a user brings a part (32, 30) of his body into contact with said electrically conductive touch zone (20), characterized in that the leakage current detection (If) comprises processing upstream of a leakage current signal taken from a point of said electrically conductive zone (27), to discriminate er any non-tactile signal, in particular any signal induced on said electrically conductive area (27) by external disturbances.  2. A touch control method according to claim 1, characterized in that it further comprises an upstream treatment of the single-phase alternating source voltage (V) to limit any overvoltage liable to induce untimely phase commands.  3. Tactile control method according to one of claims 1 or 2, characterized in that it further comprises an increase in the intensity of the leakage current passing through the touch area (20) and the electrically conductive area (27 ).  4. A touch control method according to any one of the preceding claims, characterized in that the processing of the leakage current signal is adapted to provide detection of touch control in a wide range of leakage impedance (31).  5. Device (10) for controlling in touch mode the supply of electrical equipment (2), in particular lighting equipment, from a single-phase alternating voltage source (V), comprising:  - controlled bidirectional switch means (15) for generating adjustable fractions of half-cycles of supply voltage from the single-phase alternating voltage source (V),  - Means (100) for phase control of said bidirectional switch means (15), in particular on the basis of a leakage current signal (If) between a tactile zone (20) located near an electrically conductive zone (27 ) and a neutral reference (N) associated with said single-phase alternating voltage source (V), this leakage current (If) being generated when a user brings a part (32, 30) of his body into contact with said zone touch (20), this device implementing the method according to any one of the preceding claims, characterized in that it further comprises means (FR) for processing said current current signal taken from the electrically conductive area ( 27) so as to discriminate any signal induced on said conductive area (20) by external disturbances.  6. Device (10) for touch control according to claim 5, characterized in that the processing means (FR) of the leakage current signal are arranged to provide leakage current detection when the leakage impedance (Zf) associated with the control contact is of very high module.  7. Tactile control device (10) according to one of claims 5 or 6, characterized in that the means (FR) for processing the leakage current signal are further arranged to provide leakage current detection when the leakage impedance (Zf) associated with the control contact has a very low module.  8. Touch control device (10) according to claim 7, characterized in that the means (FR) for processing the leakage current signal are further arranged to increase the intensity of the leakage current (If)  9. Tactile control device according to any one of claims 5 to 8, characterized in that it further comprises means (FC; 162) for processing the single-phase alternating voltage (V) upstream of the phase control means (100) so that said phase control means (100) are substantially immune to any disturbance conducted from the single-phase alternating voltage source (V).  10. Tactile control device (10) according to any one of claims 5 to 9, further comprising means (VS) for supplying the phase control means (100) from the single-phase alternating voltage (V) and means (17) for regulating the supply voltage generated by said supply means (VS), characterized in that these regulation means are oversized in current with respect to the nominal dimensioning recommended for said phase control means for a sensitive control operation.  11. Tactile control device (10) according to claim 10, in which the supply means (VS) comprise at least one rectifier component and a capacitive component (19), characterized in that it also comprises a resistive component (18 ) arranged upstream of the phase control means between the phase line (Ph) and the supply means (VS) for discharging said capacitive component (19).  12. Application of the touch control device according to any one of claims 5 to 11, to the control of a lamppost comprising a tubular structure (24), characterized in that the touch zone (20) covers in whole or in part the outer face of said tubular structure (24).  13. Application of the touch control device according to any one of claims 5 to 11, characterized in that the touch zone (20) is made of wood.  14. Application of the touch control device according to any one of claims 5 to 11, to the control of a single-phase electric motor.