EP2027756A1

EP2027756A1 - Electrical power supply circuit device for at least one electrical and/or electronic component

Info

Publication number: EP2027756A1
Application number: EP07765388A
Authority: EP
Inventors: Andrés Gabriel MORESCO; Washington Adhemar PÉREZ IGIEL; Juan Martín TONELLI BANFI
Original assignee: Osram GmbH
Current assignee: Osram GmbH
Priority date: 2006-06-15
Filing date: 2007-06-13
Publication date: 2009-02-25
Also published as: KR20090023697A; AR054478A1; CN101467492A; WO2007144365A1; ZA200809313B; AU2007260021A1

Abstract

A device with an electrical supply circuit with at least one electric and/or electronic component (1) connected in series and that are supplied with a direct current, wherein the components in turn are connected in series with a current rectifying module (3) and current regulating module (5), whereby said device permits connecting directly to an alternating current supply source (2) without the need for transformers nor capacitors.

Description

ELECTRICAL POWER SUPPLY CIRCUIT DEVICE FOR AT LEAST ONE ELECTRICAL AND/OR ELECTRONIC COMPONENT

INVENTION ABSTRACT

Field of the Invention

This invention is related with the field of supplying electrical power to an assembly of electrical or electronic components, more specifically with the combination of a plurality of components to be powered by electrical energy related to a minimum number of electronic components that will allow for their direct connection to the electrical power source available in the home without the need for transformers and to ensure the preservation of the useful life span of said components through the regulation of the maximum current permitted.

Even when this present description makes particular reference to the use of LED's, it should remain clear that the electrical design of the invention is applicable to any other type of electrical or electronic component that needs to be powered by direct electrical current.

Description of the Device

The Light Emitting Diodes commonly called LED' s have evolved up to today to providing advantages with respect to the traditional illuminating devices with incandescent filament lamps, fluorescent tubes and other types of conventional lamps.

The advantages presented by these types of devices are inherent in the principles of their functioning and their form of construction by being able to provide a useful life span of up to 100,000 hours of functioning and they are physically robust thereby allowing them to function well even when submitted to knocks and variations in temperature and humidity.

LED' s are currently available in a wide variety of colors, both the primary light colors as well as its variations and combinations due to the low integration of the same component or encapsulation.

One of the distinct characteristics of this type of illuminating device resides in the fact that it is made up by a semiconductor commonly called a diode that has the property to allow the passage of current in only one direction, that is to say that the LED only functions if voltage is applied between its two terminals in a manner concordant with the directional flow of current of the light emitting device.

Together with this requirement, there is also the need to provide a controlled electric current within certain safety margins to prevent overheating and the consequent non-utilization or premature aging of the semiconductor .

For informative purposes we would like to state that the voltage that is necessary for the functioning of an LED is on an average of three (3) volts of direct current (3VDC) with a consumption that averages around 2OmA.

The need to employ assemblies or arrays of LED' s and supply energy to those same through a home electrical connection of an alternating power source, has brought about the use of complementary electrical devices such as the voltage transformers currently in use.

As a reminder, the electrical energy available through the electrical power network in the home depends on the country where it is generally established at 110 or 220 volts of alternating electrical power (110 VAC or 220 VAC) . For this reason it is necessary to use voltage transformers for supplying the terminal connections of the LED' s with a lower and constant voltage of approximately 3 V.

We would like to point out that the use of transformers that make up part of the connecting circuits of the LED' s from an electrical point of view, introduces the dissipation of power, and from a physical point of view, the need to contemplate its weight and physical space necessary for the correction location and ventilation of said transformer.

Certain designs also incorporate capacitors, which are components used for storing electrical energy between two internal metallic plates separated and insulated from each other with a dielectric so that later they can release this stored energy as direct current to the consumption circuit .

Said capacitors have the characteristic to allow for a diminishing in the fluctuation of the continuous current but have disadvantages. In the first place, such as a dangerous degree of the storage of high voltages with no load when the circuit is disconnected, and in the second place, the introduction of capacitive reactance impedances in the circuit; generating a post need to correct this perturbation with the addition of a system for the correction factor of the power on the consumption line, and in the third place, the need to have a non-reducible physical volume of space available due to its construction characteristics that add to the device under study instead of the need to generate a simple device with reduced physical characteristics.

In those circumstances where it is necessary to have a considerable reduction in the weight, volume and connection simplicity, the use of transformers and capacitors generate a significant difficulty for both the installer as well as the user.

Some alternatives have been developed and as a way of reference, we can mention the U. S. Patent Application Request No. US 20020149938 that makes reference to diverse types of LED arrays connected in series and in parallel with the purpose of allowing a direct connection of an array of LED' s to the voltage and alternating current supplied by an electrical power network.

In the referenced publication it is possible to observe a broad description but with the purpose to justify the unnecessary need of current regulating elements in a plurality of LED' s interconnected in series. A large part of this fundament is based in that it admits short periods of excess current at the expense of compensating for this prejudicial state with a medium term period of cooling due to the fact that said circuits function during one half of the voltage full-wave supplied in an alternating manner. Said affirmation recognizes a period of undesired heating in the semiconductor that is later depreciated in function of the cooling periods available between the cycles of the alternating current's power source.

Besides this, said device only uses one half of the sinusoidal full-wave of the power source's current and for that, the advantage of the total full-wave is compensated for by adding a second string of LED' s in series with a polarity that is opposite from that of the first string. This means that this determines a non-utilization of one half of the LED' s during each half cycle of the alternating current's full-wave.

A factor that is also important in the utilization of the complete full-wave in its two cycles is due to the frequent flickers that are presented, in particular in a string of LED' s as the quantity of components in series are increased and the lowering of the frequency of the wave. In the first case this is due to the inertia of the string of LED' s and in the second case this is due to the increase of time between the periods of turn on and turn off.

The hypothesis mentioned in said patent finally ends up by putting together a string of LED' s connected in series and that are deprived of any intermediate current regulating device. As a conclusion, it is possible to deduce that said configuration is carried out at the expense of a premature deterioration of the light emitting diodes .

Experimental studies such as "Solid State Lighting: Failure Analysis of White LED' s" by the Authors N. Narendran, & Gu. J. P. Freyssinier, H. Yu, and Deng, affirm that even though the LED' s rarely present a catastrophic failure, nevertheless, their degradation over time is due to factors of aging, not only in the semiconductor but also in the aging of the epoxy encapsulation.

Said premature aging is manifested in a transparent period and whitening of the LED' s in function of the low circumstances of resistive heating (ohms) .

Said study also demonstrates that said degrading phenomenons are directly associated with the degree of heating suffered by the junctions of the semiconductor.

Currently the useful life span of LED' s used for purpose of efficient white lighting is where the luminescent flow does not go below 80% of the initial luminescent flow and to this end, we could cite the Article "What is useful life for white light LED's?" Journal of the Illuminating Engineering Society 30 (1) : 57-67. Narendran, N., J. Bullough, N. Maliyagoda, and A. Bierman. 2001.

Since one of the technical advantages and the key commercial aspect of these light emitting diodes consists of their long useful life, and at the same time the understanding that the main reason for the aging of the device or lighting array is the degradation caused by resistive heating; it is considered important and necessary to provide said device with an integrated regulating element just as simple as the rest of the assembly and with a minimum number of components that have the clear function of regulating the phenomenon of the undesired resistive heating of the referred device or array.

In the same manner, we could make an extensive analysis of a variety of commonly used electrical and electronic components with similar consumption characteristics as those mentioned for the light emitting diodes of the preferred example. We could cite as a way of an example, the use of direct current motors with functioning voltages lower than that of the commercial electrical power network that could be operating at 24 Volts, 12 V, 6 V, 3 V and 1.5 V amongst others, and in whose case the stabilized supply of voltage and current contribute to the proper functioning and preservation of those same. It is important to note, that one of the main causes for the deteriation of the insulation of the windings in said motors occurs due to the excessive heating of those same because of over currents being applied to them.

We could also cite as an example, the need for the recharging in rechargeable batteries where it is necessary to provide them with a regulated voltage and current in such a way as to accompany the speed of the recharging of the internal chemical charge. In this case, the over currents that could be produced provoke a shortening of the useful life and a loss of the total charge capacity throughout the period of the successive cycles.

There are a large variety of components that require being supplied in the same manner, and only as a way of reference we could cite some such as the OLED (Organic Light Emitting Diode) , PLED (Polymer Light Emitting Diode) , TOLED (Transparent OLED) , FOLED (Flexible OLED) and similar others.

In virtue of the current technical state available for the attention to these deficiencies, it would seem to be convenient to be able to count on a circuit that is homogenous in its simplicity and that is capable of supplying a group of electrical or electronic components connected in series, directly from the public electrical power network without the need of using transformers and capacitors, by contemplating the regulation of the current so that it does not exceed the maximum allowable current for the proper functioning of the component or components utilized.

BRIEF DESCRIPTION OF THE INVENTION

Therefore the purpose of this present invention provides for an array of electrical or electronic components, in particular made up by LED's, to be electrically supplied directly and together from a voltage source providing alternating current and whereby it could consist of an array that is extensive and made up by commonly used electrical and electronic components with similar consumption characteristics as those cited for light emitting diodes.

Another purpose of this invention is to provide a modular illumination array consisting of a plurality of LED' s connected between each other.

Another purpose of this invention is to provide an array that is directly connectable to an alternating electrical power source without the need of external elements such as transformers and capacitors.

Another purpose of this invention is to provide an array that will allow for the direct connection to the alternating power source of the public electrical power network and, that this is not achieved at the expense of a premature degradation of the useful life of the electrical or electronic components utilized, and in the particular case of example, of the useful life of the light emitting diodes .

Another purpose of this invention is to provide an electrical power supply circuit device with a least one electrical and/or electronic component, whereby said device allows for being directly connected to an alternating current power source without the need of voltage transformers, where at least one component is connected in series with a circuit that includes a rectifying module for the electrical voltage full-wave that in turn is connected in series with a regulating module for electrical current, where said rectifying module has an input directly connectable to said alternating power source .

Other additional purposes as a way of example of this present invention will be mentioned in the section corresponding to the Detailed Description of the invention and in the re-vindication annexes.

BRIEF DESCRIPTION OF THE DRAWINGS

For better clarity and understanding of the purpose of this invention, this same has been illustrated in various Figures, where the invention has been represented in one of the preferred forms of being made, all as a way of example, in where:

Figure 1 depicts an electronic circuit schematic with all of the components corresponding to the invention device with an electrical power source of 220 VAC; Figure 2 depicts an electronic circuit schematic with all of the components corresponding to the invention device with an electrical power source of 110 VAC; and

Figure 3 depicts a graphic in function of the time of the voltage and current curves obtained at the terminals o fan electrical or electronic component in accordance with the circuit of this invention where the values of time are given in milliseconds.

DETAILED DESCRIPTION OF THE INVENTION

The device consists of an electronic circuit composed at least by a plurality of light emitting diodes connected in series, in that each terminal of the cathode of one of the LED' s is connected with the terminal of the anode of the adjacent LED and so on successively to form the string of LED's. Once again, we would like to point out that even though the illustrated components are LED's 1, these components could be batteries, motors and other components such as had been previously mentioned.

The quantity of light emitting diodes available in the circuit depends on the supply voltage of the alternating electrical power network 2, that generally is found to be standardized in two different voltages in accordance with the region and country that is being referenced to, and in the following we will define and nominate them with the acronym VAC to make reference to an alternating current voltage.

Said string or strings of LED' s are then found to be connected in series to a current regulating module 5 that is then supplied by a current rectifying module 3 that has a direct connection to the alternating power source.

For better clarity and explanation, we are including the description of the two preferred models whereby the first one corresponds to a supply voltage of 220 VAC and the second one to a supply voltage of 110 VAC.

Example 1 - Power Source with 220 VAC

In the case of Figure 1, a string can be observed that is made up by 72 luminescent semiconductors or LED' s 1 where this number is calculated according to the supply voltage of the 220 VAC. In particular, the procedure for calculating the election of this number of components n_c arises from dividing the total voltage available V_ac by the individual voltage to be supplied to each component V_ind to make the necessary average current circulate between each one of the terminals.

As a reminder, we need to discount the additional voltage drop produced by the transistor and the first resistor Rl in series with the current regulating circuit adopted for the 72 LED' s mentioned.

In order to take advantage of the positive and negative half cycles of the power source full-wave and according to the invention, a current rectifying module 3 has been provided that is composed of 4 diodes connected between each other according to Figure 1, ensuring the complete rectification of the full-wave.

Even though a current rectifying bridge has been described in the configuration based on diodes, it is also possible to adopt a current rectifying integrated component or adaptations of the same that will allow obtaining a complete rectification of the full-wave.

As described previously, when we encounter an alternating current supply source, this same results in being variable in time and at certain moments of the cycle, it could surpass the normal value of the maximum allowable electrical current of the light emitting diodes or other electrical or electronic components that are utilized.

This phenomenon can be accented by including the involuntary presence of parasite currents and over voltages coming from other equipment, and for this reason, a current regulating module 5 is included to ensure the provision of an allowable current that will permit an effective illumination of the light emitting semiconductors without exceeding the maximum allowable current for those same.

The current regulating module 5 has an input terminal and an output terminal. Its input terminal is connected to the current rectifying module 3 and its output terminal is connected to the electric and/or electronic components 1.

Said current regulating module 5 is composed of a transistor 6 whose collector is connected to the positive voltage output of the current rectifying module 3 and whose emitter is connected by means of a resistor "Rl" indicated in reference 7 of 100 Ω to the free anode of the group of light emitting semiconductors connected in series.

Besides this, said module has a second resistor "R2" indicated in reference 8 of 3.3 KΩ that is for supplying the current to the base of the transistor that allows the passage of current from the emitter to the collector .

Even though a transistor that is configured as NPN has been used, it is possible to use a transistor with a configuration of PNP by carrying out the necessary adaptations of the locations of components in the circuit. Also a Field-Effect-Transistors can be used in stead of the shown Bipolar-Transistors.

In order to complete the makeup of the current regulating module 5, there is a zener diode indicated in reference 9 that counteracts the current supplied by the second resistor 8 when the current circulating from the first resistor 7 generates a voltage drop that surpasses the breakdown voltage of said zener diode.

Therefore, it is possible to achieve a regulation of the current by establishing diverse combinations of resistors and zener diodes responding to the sum of the voltages in general with the following formula:

Where V₀₂ is the voltage rating of the zener diode, V_BE is the voltage characteristic of the functioning of the transistor selected under the functioning conditions of the circuit, I_E is the current circulating in the circuit and through the first resistor "Rl", whereby said resistor is connected in this case to the emitter of the transistor.

Since the end purpose of this present circuit is to generally ensure a current of 2OmA to the LED' s and having selected as a way of example, a value of breakdown voltage of the zener of 2.7 Volts coming from the value of the first resistor for the circuit of Figure 1 of the equation, we obtain:

Y -Y 2 IV -0 IV ¹ I_E 0.02Λ

Therefore this would be the value in Ohms adopted for the first resistor Ri of the current regulating module identified in particular in Figure 1 with the reference 7 when the supply power source of the circuit is 220 VAC.

It should be noted that all values for eletrical magnitudes or components have a tolerance that is usually 20%

Example 2 - Power Source with 110 VAC

Figure 2 shows a configuration that is generally similar to that of Figure 1, where there is a supply voltage 2 that in this case results in being 110 VAC. This same is rectified through the rectifying module 3 generally composed of 4 diodes that are supplying the current regulating module 5 that is in turn connected in series this time to two parallel strings made up by LED' s 1 that are in turn, connected in series.

This configuration of parallel strings allows for the use of the same quantity of LED' s as in the configuration of Figure 1, but since the power source supply has only one half of the voltage in this second example, the distribution of the voltages is done with half of the components that are connected in series.

As a consequence of the division of the current into two branches, and whereby each branch should also be provided with an approximate average current of 2OmA, the current circulating to be regulated in the current regulating module in this case would be the one corresponding to the sum of the currents in both branches, that is to say an average of 4OmA.

Therefore it is possible to achieve the regulation of the current by establishing diverse combinations of resistors and zener diodes responding to the sum of the voltages in general by using the following formula as in the prior example:

V_D2=V_BE+ I_E-R₁

Where V₀₂ is the voltage rating of the zener diode, V_BE is the voltage characteristic of the functioning of the transistor selected under the functioning conditions of the circuit, I_E is the current circulating in the circuit and through the first resistor "Rl", whereby said resistor Ri finally is connected to the emitter of the transistor

Since the end purpose of this present circuit is to generally ensure a current of 2OmA to the LED' s and having selected as a way of example, a value of breakdown voltage of the zener of 2.7 Volts, coming from the value of the first resistor for the circuit of Figure 2 of the equation, we obtain:

V_D2 -V_{BE =} 2.7V - 0.7V

*i = = 50Ω /_r ^~ 0.04Λ

Due to the fact that the electrical and electronic components function within a current range and a range of voltages, it is logical to adopt values of the functioning for the current and voltages that fall within this range. Based on this characteristic, that is to say that the value of the resistors selected, as well as the rest of the components could vary within the determined range; this is in particularly due because there are pre-established values of resistors, voltage breakdown values of zeners as well as other characteristics of the rest of the components of this present invention that are commercially available.

Likewise, said variations continue following the identical calculation logic and selection developed herein.

As a clear example of this result is the adoption of the first resistor having a value of 47 Ohms for the circuit in Figure 2 since this is the commercial resistance value closest to the theoretical value of the calculation of 50 Ohms. In reference to the behavior obtained from the voltage and current that circulate through the LED's, there are measurements available that were made with an oscilloscope as shown in Figure 3 where the following may be observed: the curves of voltage 11 are seen to be rectified, that is to say that both are seen as consecutive cycles in the same direction and polarity with respect to the axis of voltage zero (0) . The voltage curve is seen to exceed the minimum value of the turn on voltage 12 of the components during the major part of the cycle and besides this, it never exceeds the maximum allowable voltage in 13. On the other hand, the current curve 14 circulates through the LED' s during a period when the voltages get close to the minimum theoretical turn on voltage 12, being able to exceed the minimum turn on current value 16, but never reaching the point of exceeding the maximum allowable current 15 for said LED's.

Continuing with the reasoning of the prior two circuits, it is evident that with an understanding of the material, it is possible to adopt intermediate solutions where the supply source voltages are different than the ones in the examples and it is possible to come up with different devices of LED' s in series and in parallel to obtain the circulation of the desired current. Since this invention is best illustrated according to the examples described previously, these same should not be interpreted as a limitation imposed of the scope of this invention. On the other hand, it should be clearly understood that it is possible to recur to other work, modifications and equivalents of the same after having read this present description. This could occur to those who are knowledgeable in the subject without departing from the spirit of this present invention and/or scope of the Claims Annexes .

Claims

CLAIMSHaving especially described and determined the nature of the present invention and the way that it can be put into practice herein, what is claimed as exclusive property and right is:

1. A device with an electrical supply circuit configured to supply at least one electric and/or electronic component (1), where said device will allow for being connected directly to an alternating current power source (2) without the need of voltage transformers since the device is characterized in that at least one of said electric and/or electronic components (1) is connected in series with the supply circuit that includes an electrical voltage full-wave rectifying module (3) that in turn is connected in series to an electrical current regulating module (5) where said rectifying module (5) has a connection that is directly connected to said alternating current power source (2).

2. The device in Claim 1, wherein said electrical voltage full-wave rectifying module (3) is comprised of at least one voltage rectifying diode (4) connectable to the alternating current power source (2).

3. The device in Claim 1, wherein said electrical current regulating module (5) comprises an input-terminal that is coupled to the electrical voltage full-wave rectifying module (3) , an output-terminal that is coupled to at least one of the electric and/or electronic components (1), and at least one transistor (6) with a collector, a base and an emitter terminal, wherein the collector terminal is coupled to the input terminal, the emitter terminal is coupled to the output terminal via a first resistor (7), and the base terminal is coupled to the input terminal via a second resistor (8) and to the output terminal via a zener diode (9) .

4. The device in accordance with Claim 3, wherein the at least one transistor (6) is of the type PNP.

5. The device in accordance with Claim 3, wherein the at least one transistor (6) is of the type NPN.

6. The device in accordance with anyone of the prior claims, wherein it is said that at least one electric and/or electronic component (1) makes up a plurality of LED' s that make up at least an illumination array or assembly, being that said plurality of LED' s are connected in series with said supply circuit.

7. The device in accordance with anyone of the prior claims, wherein it is said that the alternating current power source (2) provides a voltage with a value of 220 VAC.

8. The device in accordance with Claim 7, wherein it is said that the LED' s connected in series consist of a total of 72 LED' s.

9. The device in accordance with Claims 7 or 8, wherein it is said that the first resistor (7) has a value of 100 Ohms.

10. A device in accordance with Claims 7 or 8, wherein the second resistor (8) has a value of 3.3 Kilohms.

11. The device in accordance with Claims 7 or 8, wherein the zener diode (9) has a breakdown voltage of 2.7 Volts.

12. The device in accordance with anyone of Claims 1 to 6, wherein said alternating current power source (2) provides a voltage with a value of 110 VAC

13. The device in accordance with Claim 12, wherein said LED' s connected in series consist of a total of 72 LED' s in two branches of 36 LED' s where each branch is connected in parallel at their ends.

14. The device in accordance with Claim 12 or 13, wherein said first resistor (7) has a value of 47 Ohms.

15. The device in accordance with Claim 12 or 13, wherein said second resistor (8) has a value of 3.3 KΩ.

16. The device in accordance with Claim 12 or 13, wherein it is said that at least one zener diode (9) has a breakdown voltage of 2.7 Volts.

17. The device in accordance with Claims 1 to 5, wherein it is said that at least one electric and/or electronic component composes a plurality of direct current motors that make up at least a group of motors, being said plurality of motors connected in series with said supply circuit .

18. The device in accordance with Claims 1 to 5, wherein it is said that at least one electric and/or electronic component makes up a plurality of rechargeable batteries that make up at least a group of batteries, being said plurality of batteries connected in series with said supply circuit.

19. The device in accordance with Claims 1 to 5, wherein it is said that at least one electric and/or electronic component makes up a plurality of PLED' s that make up at least a group of PLED's, being said plurality of PLED' s connected in series with said supply circuit.

20. The device in accordance with Claims 1 to 5, wherein it is said that at least one electric and/or electronic component makes up a plurality of OLED' s that make up at least a group of OLED' s, being said plurality of OLED' s connected in series with said supply circuit.