ITVI20130308A1 - MULTIFUNCTION LED LIGHTING CYLINDRICAL TUBE - Google Patents

Description

MULTIFUNCTIONAL CYLINDRICAL TUBE FOR LED LIGHTING

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The present invention generically refers to a multifunction cylindrical tube for LED lighting. More specifically, the invention relates to a new multifunctional LED lighting device that can be integrated into cylindrical lighting tubes, usually used to replace fluorescent lamps (for example, of the T8 type).

There are still LED lighting devices on the market integrated inside cylindrical tubes having the same dimensions as linear fluorescent tubes (the T8 type tubes, for example, have a diameter of 26 mm), designed for tube replacement. same fluorescent.

There are, for example, lighting devices suitable for replacing respective 36W or 58W fluorescent tubes of the T8 series, with a diameter of 26mm and lengths between 1 and 1.5m. These new devices house the LEDs on one of the two sides of the cylindrical tube, thus illuminating only the half-space facing downwards, once inserted into the lighting fixture; in this way, with the same light efficiency of the sources, an electrical energy saving of at least 50% is obtained compared to the traditional fluorescent solution (in the absence of optical devices for recovering the light dispersed upwards, in the case of the fluorescent lamp ).

These known devices integrate an electronic power supply, which, starting from the original power supply (alternating current, AC) of the pre-existing fluorescent lamps, provides the correct direct current (DC) for powering the LEDs.

The purpose of the present invention is to create a multifunction cylindrical tube of LED lighting, which, incorporated within the cylindrical lighting tubes of a known type, is highly efficient and which allows, at the same time, to perform various functions remotely.

Another purpose of the present invention is to create a multifunction cylindrical tube for LED lighting, which allows the use of traditional light sources without modifying existing supports and / or lighting systems.

A further purpose of the invention is to realize a multifunction cylindrical tube for LED lighting, which is able to self-regulate the light emitted according to the ambient light, so as to automatically reduce the light emitted in the presence of ambient light of natural origin, with the advantage of a significant saving of electricity consumed.

These and other purposes are achieved by a multifunction cylindrical tube for LED lighting, according to attached claim 1; other detailed technical characteristics, according to the present invention, are provided in the further dependent claims.

Advantageously, the invention describes a new LED device, which can be integrated into a cylindrical tube replacing fluorescent lamps, for example of the T8 type, with the following characteristics:

- integration of a wireless spread spectrum radio transceiver capable of remotely controlling the lighting fixture to control its functions and diagnose it remotely;

- integration of an electric power meter and the electricity consumed by the lighting fixture;

- integration of an ambient light sensor and an automatic regulation circuit of the light emitted by the LED lighting device, capable of self-regulating it according to the ambient light, keeping the light constant in the illuminated environment, in order to automatically reduce the light emitted in the presence of ambient light of natural origin, with the advantage of saving electricity consumed;

- integration of a special self-calibration system of the light sensor, based on a self-adaptive algorithm to the intensity of natural light present in the environment.

Further purposes and advantages of the present invention will become clear from the following description, which refers to an exemplary and preferred embodiment of the multifunction cylindrical tube for LED lighting, according to the present invention, and from the attached drawings, in which:

- Figure 1 shows an overall block diagram of the multifunction cylindrical tube for LED lighting, according to the invention;

- Figure 2 shows an overall perspective view of the multifunction cylindrical tube for LED lighting, according to the invention;

- Figure 3 shows a partially cut-away detail view of the multifunction cylindrical tube of Figure 2, according to the invention; Figure 4 shows a cross-sectional view of the multifunction cylindrical tube of Figure 2, according to the present invention; figure 5 shows an enlarged view of an element of the multifunction cylindrical tube of figure 2, according to the present invention;

Figure 6 shows a diagram of the direct and reflected light rays in a first operating position of the multifunction cylindrical tube, according to the present invention;

Figure 7 shows a diagram of the direct and reflected light rays in a second operating position of the multifunction cylindrical tube, according to the present invention;

Figure 8 shows an electrical diagram relating to the RR transceiver circuit and light and energy meter used in the multifunction cylindrical tube, according to the present invention;

Figure 9 shows an electrical diagram relating to the circuit A2 for supplying and regulating the LEDs used in the multifunction cylindrical tube, according to the present invention.

With reference to the aforementioned figures, the TL multifunction cylindrical tube for LED lighting, suitable for replacing traditional tubes, for example of the T8 type, according to the present invention, has an external cover in transparent translucent polycarbonate CC and an internal extruded aluminum EE and includes a radio transceiver RR, also suitable for energy metering, which governs an electronic power supply A2, capable of regulating the brightness of the environment and connected, on the one hand, to the power supply network R at 230V AC and, on the on the other hand, to a light source, such as a linear strip of S2 LEDs.

The TL electron tube also incorporates an SL brightness sensor, which measures the LR light reflected from the floor of the environment, and the A1 antenna of the RR radio transceiver.

In particular, the electronic power supply A2 drives a linear strip S2 of high efficiency white LEDs and is powered by the 230V AC network R, through the two metal contacts present on one of the two standard electrical terminals T1, T2 of the tube TL, while the other terminal has the metal contacts short-circuited to ensure electrical continuity in the ceiling light in which the multifunctional electronic tube TL is mounted, replacing the traditional fluorescent tube (for example, of the T8 type). The operation of the multifunction cylindrical tube for LED lighting, according to the present invention, is essentially the following.

When the electron tube TL is powered at an alternating voltage between the rated operating limits, an AC / DC converter supplies direct current to the linear LED strip S2 and supplies a service power supply to the auxiliary radio communication, measurement and control circuits. adjustment.

In the case of replacement of 58W fluorescent tubes, for example, the electrical operating parameters are as follows:

- original fluorescent tube power = 58W;

- total luminous flux = 5000 lumens;

- total power absorbed by ballast feCu power supply tube = 67W (CELMA class B2); - FeCu ballast power supply = 9W (67-58W); - AC current = 0.53A;

- AC voltage = 230V.

Using a linear strip of S2 LEDs with a luminous efficiency of 110 lumen / W, with an optical system efficiency of 85%, approximately 2500 ÷ 3000 lumens are needed to obtain the same flux of a fluorescent tube in the lower half space and, assuming 3000 lumens , the power of S2 led strip needed is about 3000/110 / 0.85 = 32W.

If the electronic power supply A2 of the S2 led strip has an efficiency of 90%, a necessary AC power of less than 36W is obtained.

Leaving the original FeCu ballast power supply of the fluorescent tube connected (to facilitate the replacement of the fluorescent tube), the additional loss in the original ballast power supply is in any case not greater than 1.5W, thanks to the reduced power supply current of the new TL multifunction cylindrical tube , which, to absorb 36W, requires only 0.19A at 188V AC, the minimum voltage that is established at the contacts of terminals T1, T2 of the new TL tube with the original ballast power supply in series. In this condition, the TL multifunction electronic tube according to the invention produces the same light as the original fluorescent tube, absorbing just over half of the electrical power, with a saving of 46%.

Since the new TL electron tube is able to self-regulate its brightness by decreasing it up to, for example, 15% of the maximum value, bringing it to a minimum brightness, this new TL electron tube will only be able to absorb 5W, with an AC current of about 22mA, a voltage across it of about 224V and an overall electrical power saving of over 93%; alternatively, by reducing the power to about half of the maximum power, absorbing 17W of electricity, the power saving of the new TL tube is 77%.

The great advantage of this solution is clear, in saving electricity used for lighting; in particular, the self-regulation of the brightness allows to obtain very high savings in electricity, simply by replacing the original fluorescent tubes with those of new type, in the existing lighting fixtures, maintaining the same minimum lighting conditions prior to replacement.

In particular, the multifunctional LED cylindrical tube TL, object of the invention, integrates the light or brightness sensor SL necessary for self-regulation.

The TL LED tube, in fact, immediately after the first installation, activates an automatic self-calibration procedure of the SL light sensor, which allows the TL tube itself to adapt to the light characteristics of the environment in which it is positioned.

In practice, the TL tube measures the LR light reflected from the floor and from the illuminated objects and, based on this measurement, the brightness adjustment takes place, the aim of which is to keep the quantity of reflected light LR constant over time.

The reflected light LR is the sum of the light projected on the floor by the luminaire in which the TL LED electronic tube is mounted and the natural light present in the environment, coming for example from windows and skylights, so it is evident that to keep constant this sum is equivalent to automatically decreasing the light emitted by the LED electronic tube TL when the ambient light increases.

The reflected light LR depends on many physical and geometric factors, such as the reflection coefficient of the illuminated surface, its geometric shape, the distance from the lighting fixture, the presence of various objects with non-homogeneous characteristics, etc.

The LED electronic tube TL integrates a continuous self-calibration function, which, therefore, is self-adapting to the changing environmental conditions in which the TL tube is inserted.

This new function therefore makes it possible to make the application of the new TL LED tube universal.

Thanks to the use of special adaptive calibration algorithms, the TL led tube has already measured the reflection conditions in the environment in which it is installed and is already able to estimate the correct mix of light emitted by the TL tube and natural light present in the environment, estimates that with the passing of the hours it becomes more and more accurate and automatically adapts to the geometric variations of the environment.

The RR radio transceiver, used for remote management of all functions, is for example of the "spread spectrum" type, operating in the 2.400 ÷ 2.483 GHz band and allows remote management of all the functions of the TL LED tube, such as particular:

- diagnostics of correct functioning;

- remote reading of power and energy consumption data;

- remote management of switching on, switching off and dimmer mode;

- the measurement of the various functional parameters.

Furthermore, the brightness control circuit CL is integrated into the RR radio transceiver circuit (shown in detail in the attached figure 8), and includes a single MPR microprocessor, with integrated digital radio transceiver, which implements the communication functions, as well as the functions measurement and control of the brightness and power supply A2 of the linear led strip S2.

The MPR microprocessor also supervises the measurement of the power and energy absorbed by the A2 power supply, through MIS circuits; in particular, the energy measurement is carried out by integrating the instantaneous power and accounting for the electricity consumed by the LED electronic tube TL and the energy consumed data is always available for consultation via radio.

The A2 power supply incorporates a high-frequency switching current regulator REG (shown in detail in the attached figure 9) for driving the S2 led strip at constant current.

The measurement of the electrical power absorbed by the TL electron tube can be carried out in two ways:

A) by direct measurement of the power (according to this technique, the measurement is carried out by reading the instantaneous values of rectified current and voltage at the input of the electronic power supply A2 of the LED tube TL, with a measurement accuracy of less than 2% );

B) by an indirect measurement of the power, by means of an estimator of the state of the tube TL. (In this case, the metering accuracy of the consumed power and energy is affected by a greater error, in any case less than 10%, but the advantage of this solution is given by the lower cost of the metering device, as the instantaneous power is estimated by the MPR microprocessor itself, which, acting on the REG control circuit of the LED tube TL and thus determining its brightness at all times, is aware of the set value; the set value is in univocal relation with the real power absorbed by means of a table stored in the MPR microprocessor and obtained in the factory by measuring various operating states at different brightness and temperature of the product. Then, the MPR microprocessor relates the set value with the real power absorbed by the table and records, instant by instant, storing it in its memory, an estimate based on the percentage of brightness set and on the temperature of the led tube TL). As shown in detail in figures 2, 3 and 4, the LED electronic tube TL is built with two extruded profiles, i.e. an internal extruded aluminum EE, which acts as a support for the electrical and / or electronic parts and as a heat sink of the heat produced by the linear strip of S2 LEDs, and an external CC cover, made of polycarbonate, which has the function of an aesthetic finish and diffusion of light.

The internal profile in extruded aluminum EE is also hollowed out in a central area along its length (references FR in figure 3) in order not to close the electronic circuits containing the antenna A1 of the RR radio transceiver, which in this way can overlook the exterior without shields.

The CC profile or external cover in polycarbonate provides for electrical insulation and diffusion of the light emitted by the linear led strip S2, through the glass of the VP ceiling light.

The tube is closed at both ends with two plastic terminals T1, T2, which integrate the metal contacts for the electrical connections, and one of the two terminals T1 is specially shaped to house the brightness sensor SL, as shown in detail in figures 5 , 6 and 7 attached.

The SL brightness sensor (preferably made up of a special photodiode or phototransistor FF with spectral response curve calibrated to the sensitivity of the human eye) is housed inside a telescope-shaped CH element and obtained at one end of the T1 terminal body. .

According to preferred embodiments, the telescope element CH, acting as a lampshade, is cut at a correct height, so as to minimize the quantity of light rays R1 emitted by the led strip S2 of the tube TL and reflected on the internal surface of the glass of the VP ceiling light in which the LED electronic tube TL is housed (figures 6 and 7).

In fact, these reflected rays constitute a disturbance for the correct measurement of the useful light, which corresponds to the rays of light R2 reflected from the floor of the area illuminated by the tube TL itself.

In a suitable version automatically adaptable to all types of ceiling lights, the telescope element CH is telescopic and equipped with an ML spring, so that its height automatically adapts to the height available between the TL tube and the glass of the VP ceiling light, completely eliminating the possibility of the formation of spurious reflected rays, such as that indicated with RS in the attached figure 6. The radio communication electronic circuit, shown in detail in the attached figure 8, consists of a transceiver with integrated MPR microcontroller, for example of the "spread spectrum" type, operating in the 2.400 ÷ 2.483 GHz band, and by the appropriate interfacing and Power supply.

The measurement of the light intercepted by the brightness sensor SL is carried out by means of the control circuit CL, which includes a double ramp converter consisting of IC108, Q1 and the relative passive components, while the measurement of the electrical power consumed by the LED tube TL is carried out from the MIS circuit by measuring the rectified mains voltage at 100Hz (MEAS_VIN signal), a signal that is reported to an A / D input of the microcontroller integrated in the RR radio transceiver, and of the rectified electric current at 100Hz, amplified by the amplifier IC109, whose output signal is returned to another A / D input of the microcontroller integrated in the RR radio transceiver.

The products of the instantaneous values of voltage and current subsequently integrated over time generate the measurement of the active power absorbed by the LED tube TL and the energy consumed is calculated as an integral of the active power values.

The RR radio transceiver also integrates a temperature sensor, which, by recording the internal temperature of the TL LED tube, allows you to make any corrections in the measurement of power, depending on the temperature, to improve its accuracy.

The power supply circuit A2 of the linear led strip S2, illustrated in detail in the attached figure 9, consists of a high frequency switching buck converter (about 100KHz) driven by a suitable integrated controller REG, which drives the switching MOSFET transistor Q1 according to a suitable PWM modulation; the controller has a regulation input, connected to terminal J8C, whose voltage determines the average value of the output current of the converter.

The RR transceiver in Figure 8 acts on the voltage of this input (DIM signal in Figure 8) to adjust the intensity of the current in the S2 LEDs and, therefore, to adjust the total light emitted.

The circuit in figure 9 incorporates the power measurement elements, in particular the shunt resistor R66 for measuring the current absorbed by the LED tube TL and the resistive divider R60, R62, R63 and R65 for measuring the rectified power supply voltage. .

The high frequency transformer TR2, together with the components D16, C23 and D7, provide, in a simple and efficient way, the small power supply necessary for the operation of the RR radio transceiver without significantly weighing on the energy balance of the TL led tube ( 50 ÷ 100mW consumed on the total of approximately 30 ÷ 35W, corresponding to approximately 0.1 ÷ 0.2%), while the resistive network R67, R68 and R69 supplies the RR radio transceiver with a small power supply current at reduced speed for operation minimal, able to support the basic diagnostic functions in the absence of switching on of the S2 LEDs due to a fault, in the presence of the main mains power supply R.

By exploiting the possibility of impulsive transmission of the RR radio transceiver, it is thus possible to start a radio communication with reduced performance capable of sending diagnostic information in case of failure of the main buck converter or of the S2 led light source.

The convenience of this solution for the implementation of complex functions with a simple and inexpensive circuit structure is therefore evident.

From the description made, the characteristics of the multifunction cylindrical tube for LED lighting, object of the present invention, are clear, as are the advantages. Finally, it is clear that numerous other variations can be made to the multifunction cylindrical tube in question, without thereby departing from the principles of novelty of the inventive idea, just as it is clear that, in the practical implementation of the invention, the materials, shapes and the dimensions of the illustrated details can be any according to requirements and they can be replaced with other technically equivalent ones.

Claims (9)

CLAIMS 1. Multifunction cylindrical tube (TL) for LED lighting, comprising an external cover (CC) for the diffusion of light and at least one internal extruded portion (EE), on which the electric / electronic operating circuits of the LED tube are positioned (TL), characterized by the fact that said LED tube (TL) includes a brightness or light sensor (SL), which measures the reflected light (LR) present in an environment, and a radio transceiver (RR), which governs an electronic power supply (A2), suitable for regulating the brightness in the environment and connected, on one side, to the power supply network (R), by means of two metal contacts present at one of the terminals (T1, T2) of the LED tube (TL ), and, on the other side, to a series of lighting LEDs (S2), the other two metal contacts present at the other terminal (T1, T2) of the LED tube (TL) being short-circuited. 2. Multifunction cylindrical tube (TL) as in claim 1, characterized in that said tube (TL) activates an automatic continuous self-calibration procedure of said light sensor (SL), which allows the tube (TL) to adapt to the luminous characteristics of the environment where it is installed, through a measurement of brightness or reflected light (LR) from the illuminated objects and a brightness adjustment, which is carried out, through a control circuit (CL), based on said measurement of reflected brightness ( LR), so as to keep the quantity of said reflected light (LR) constant over time, where said reflected light (LR) is the sum of the light projected on the floor by said tube (TL) and the brightness or natural light present in the environment. 3. Multifunction cylindrical tube (TL) as per at least one of the preceding claims, characterized by the fact that said radio transceiver (RR) is used for the remote management of the functions of the LED tube (TL), such as diagnostics, reading of power and energy consumption data, switching on, switching off and dimmer mode, measurement of the various parameters 4. Multifunction cylindrical tube (TL) as per at least one of the preceding claims, characterized in that said radio transceiver (RR) is an integral part of said brightness control circuit (CL) and integrates a single microprocessor, which implements the functions of communication, measurement and control of the brightness and control of said electronic power supply (A2) of the LEDs (S2). 5. Multifunction cylindrical tube (TL) as in at least one of the preceding claims, characterized in that said electronic power supply (A2) incorporates a power and energy meter. 6. Multifunction cylindrical tube (TL) as per at least one of the preceding claims, characterized in that said internal extruded portion (EE) is at least partially hollowed or milled (FR) along its length, in order to avoid electrical shielding. 7. Multifunction cylindrical tube (TL) as per at least one of the preceding claims, characterized in that one (T1) of said two terminals (T1, T2) of the tube (TL) is shaped to house said brightness sensor (SL), which is placed inside a telescope-shaped element (CH) and obtained at one end of said terminal (T1). 8. Multifunction cylindrical tube (TL) as per at least one of the preceding claims, characterized in that said telescope-shaped element (CH) is telescopic and equipped with a spring (ML), in such a way as to adapt its height to height available between said outer cover (CC) of the tube (TL) and a transparent element (VP) placed parallel to and at a distance from said outer cover (CC). 9. Multifunction cylindrical tube (TL) as per at least one of the preceding claims, characterized in that said radio transceiver (RR) integrates a temperature sensor inside said tube (TL), which allows corrections to be made in the measurement of power, in function of temperature.