WO2001091519A1

WO2001091519A1 - Led lamp

Info

Publication number: WO2001091519A1
Application number: PCT/DE2001/001862
Authority: WO
Inventors: Josef RÖDIGER
Original assignee: Roediger Josef
Priority date: 2000-05-20
Filing date: 2001-05-17
Publication date: 2001-11-29
Also published as: AU6579301A; AU6579401A; WO2001091276A1; AU6579501A; WO2001091200A1; DE10025028C2; DE10025028A1

Abstract

With the development of high-capacity and incandescent light LEDs, high intensity LED lamps that can be operated directly on the power supply system are becoming increasingly important. The novel solid state voltage transformer, which is based on modern high-intensity materials, allows a very compact construction in a standard base. The structural shape and the size of the LED lamp are proportionate to the light output. The voltage transformer acts as a capacitive load in the power supply system, which means that only a small proportion is transformed into non-electrical energy therein. As a result, essentially only reactive power is produced, which represents cost advantages. The LED lamps can be used as signal lamps throughout the entire spectrum from red to blue in industry, traffic guidance devices and advertising. LED incandescent lamps can be used for spot lighting in the construction of machines and optical devices and for edge and emergency lighting. LED infrared lamps can be used in the field of safety and in inspection systems.

Description

Led lamp

The invention relates to an LED lamp of low to medium light intensity, which can be operated directly on the power supply network.

The LED lamp is used wherever no extra low voltage is available, the properties of LED lighting bring advantages and a medium light intensity is sufficient.

Special areas of application are where low heat development is required, high vibration and shock loads occur, where certain light colors are required and high maintenance costs are incurred. The LED lamps can be used as signal lamps across the entire spectrum from red to blue in industry, in traffic management systems and in advertising.

LED white light lamps can be used as spot lighting in machine and optical apparatus construction as well as for edge and emergency lighting. LED infrared lamps are used in the security area and in inspection systems.

A large number of LED lamps and LED modules with low to relatively high light intensity are already available for operation with low voltage. Smaller LED lamps on the market for direct mains operation have only a very low light intensity and destroy about 30 to 100 times the energy required via a series resistor. Luminous LED lamps with an integrated power supply are currently bulky and bulky. LED lighting for image processing and for optical inspection systems are supplied by separate power supplies.

In the LED lamp according to the invention, an operating principle is suitably implemented that is also used in the prior application DE 100 25 028 A1 / 1 /. In the design example presented in 121, a supply voltage of a few 100 V is generated from a battery voltage for the backlighting of liquid crystal displays. Use of the active principle for downward conversion is assigned to the sensor area in 121. With the further development of the active principle and the use of a piezo multi-layer actuator, a step-down converter can be realized, which can be integrated in the lamp base with the required power conversion.

The object of the invention is to provide a new type of LED lamp which can be operated directly on the power supply network and which generates only little heat loss even at higher light intensity.

Another important task is the integration of the power supply in a standard base to ensure compatibility with common incandescent lamps. It is an object of the invention to provide an LED lamp which is designed for high vibration loads and a wide temperature range. Another object of the invention is to provide LED lamps in all common signal colors, including IR light and white light. Another object of the invention is to provide LED lamps for operation with 230V / 50Hz and 115V / 60Hz

It is a further object of the invention to provide an LED lamp which allows miniaturization in accordance with the energy conversion and the light intensity.

The object of the invention is achieved in that in a closed housing a voltage converter, consisting of a mechanical holder in the form of a hollow cylinder construction, in which an electromechanical converter and a magnetomechanical converter are arranged one behind the other and firmly connected to one another, a control IC for the network operation of the multi-layer actuator and an LED multichip module are accommodated. The electromechanical transducer consists of a monolithic multilayer actuator and the magnetomechanical transducer consists of a magnetoelastic core which is surrounded by a coil with a magnetic circuit. A permanent magnet must be used in the magnetic circuit of the magnetomechanical transducer to generate a magnetic bias. The mechanical pretension generated by the clamping should only slightly exceed the necessary minimum.

Ceramic insulators are used for safe electrical isolation. The principle of operation of the voltage converter is based on the simultaneous use of the reciprocal piezo effect and the magnetoelastic effect. The practical implementation of the interaction of the two physical solid-state effects takes place after the Principle of the motor generator, the electromechanical converter working in motor operation and the magnetomechanical converter in generator operation. This is done by means of purely translatory movements in the μm range, with the actuating forces that build up at the same time. Electrical energy is converted into mechanical energy and mechanical energy into electrical energy with little loss. With this operating principle, you can easily convert a mains voltage into a low voltage of 2V to 16V. Another major advantage of this voltage converter is the implementation of an LED lamp with an extremely compact design and an absolutely safe electrical isolation between the mains voltage and the low voltage generated.

The relatively simple and modular structure of the LED lamp creates optimal conditions for automated mass production, which significantly reduces the manufacturing costs. The use of complex LED chip modules and powerful converters suggests a high purchase price, which, however, is often justified at second glance due to the reduced downtimes and maintenance costs. Another very interesting aspect is the fact that the multilayer actuator acts like a capacitor. By means of a two-pulse voltage rectification, the multi-layer actuator is charged each time when the mains voltage increases and discharged again during the decrease, as a result of which mostly only reactive power is generated. However, the energy consumer only has to pay for the active power, which means that the higher purchase costs are refinanced after about half the life. For a safe and efficient energy conversion, some important features of the invention have to be considered when designing the novel LED lamp. When using a hollow cylinder (sleeve) for mechanical clamping of the functional elements, a slot must be provided in the longitudinal direction in the area of the magnetomechanical transducer, since the sleeve forms a massive short-circuit ring, which leads to high electrical losses. When screwing and tightening the voltage converter, it is also important to ensure that the torque is not transferred to the functional elements, which is why a positional fixation must be provided for assembly.

Due to the very different coefficients of thermal expansion of the individual components of the voltage converter, thermomechanical temperature compensation must be provided in order to maintain function and efficiency. Since supermagnetostrictive materials have a low relative magnetic permeability, special care must be taken to ensure that the magnetic resistance is kept as low as possible by means of a large air gap area.

A hermetically sealed housing should be provided in order to protect the functional elements from the direct influence of environmental influences on the one hand and on the other hand to increase the insulation capacity and service life by introducing extremely dry air. In order to ensure good dissipation of the resulting heat loss in continuous operation, a heat-conducting medium should ensure good heat transfer between the functional elements and the housing.

To operate the LED lamp, insert it into a corresponding lamp holder and switch on the mains voltage.

The mains voltage is fed to the two-pulse voltage rectifier IC via the base contacts and is passed on to the multilayer actuator as rectified half-waves with the resulting frequency doubling.

Due to the sinusoidal rise and fall of the applied voltage, the multilayer actuator expands and then contracts again, as a result of which the magnetoelastic core of the magnetomechanical transducer is compressed and relieved again. The magnetomechanical transducer is premagnetized with a permanent magnet. Due to the increasing and decreasing mechanical tension, which acts on the magnetoelastic core, it generates a variable magnetic field. This variable magnetic field creates a voltage in the coil that surrounds the magnetoelastic core. The generated voltage is led to the LED multichip module via the coil connections. The applied voltage generates a current in the direction of flow in the LED chips, which causes them to emit light. The light color is determined by the LED chips used.

An exemplary embodiment of the LED lamp and the operating principle of the voltage converter are explained below with reference to drawings.

The associated drawings show:

Fig. 1 representation of the principle of action of the integrated voltage converter

2 sectional view of the LED lamp (axial section)

3 current-voltage curve at the multilayer actuator (ideal capacitor) Fig. 4 basic circuit of a network-controlled two-pulse voltage rectifier IC on a thyristor basis

FIG. 1 shows in simplified form the basic functional elements of the LED lamp according to the invention as well as their basic arrangement and their interaction.

A pulsating DC voltage is generated from the AC voltage provided by the supply network via a two-pulse voltage rectifier IC 5, which drives a charging current into the monolithic multilayer actuator 1 with increasing voltage. When the voltage drops, the two-pulse voltage rectifier IC 5 allows the monolithic multilayer actuator 1 to feed its unconverted energy, which is still present in the form of charge, back into the supply network as a discharge current. Due to the increase and decrease in the applied voltage, the monolithic multilayer actuator 1 expands and then contracts again, as a result of which the magneto-elastic core 2 of the magnetomechanical transducer, consisting of the magneto-elastic core 2 and the coil 4 surrounding it with permanent magnet 13 and Flußleitplatte 12, compressed and relieved again. The permanent magnet 13 introduced into the magnetic circuit generates a magnetic bias of the magnetoelastic core 2. The static magnetic field of the permanent magnet 13 causes the magnetoelastic core 2 to expand in length, thereby doubling its deformability. If the magnetically prestressed magnetoelastic core 2 is pressed together by the monolithic multilayer actuator 1 and then relieved again, it generates a variable magnetic field. This variable magnetic field generates a voltage in the coil 4, which surrounds the magnetoelastic core 2, with which the LED multichip module 11 is supplied. A current in the direction of flow stimulates the LEDs to light up.

Figure 2 shows a possible design example of the LED lamp according to this invention. The axial section of the LED lamp illustrates how a reliable voltage conversion with low heating and a safe electrical isolation between mains voltage and low voltage can be achieved in a confined space. The LED lamp according to this invention has a housing 18 which is provided with cooling fins 17 in the upper region and is formed into a lamp base with integrated base contacts 8.1 and 8.2 in the lower region. In this housing 18 there is an LED Multichip module 11, a heat conductor 16, a two-pulse voltage rectifier IC 5 and a voltage converter housed.

The voltage converter is composed of an electromechanical converter, the insulator 3, a magnetomechanical converter and the mechanical clamping, consisting of the piezo holder 14 with insulator plate 7 and the magnet holder 15 with slot 21. Via the fine thread 22, the piezo holder 14 is screwed to the magnet holder 15, so that the electromechanical transducer, which is arranged one behind the other and consists of the multilayer actuator 1, and the magnetomechanical transducer which consists of the magnetoelastic core 2 and the coil surrounding it 4 with flux guide plate 12 and permanent magnet 13, mechanically directly coupled via the insulator 3. The mains voltage fed in at the base contacts 8.1 and 8.2 passes via the chip connections 9 to the two-pulse voltage rectifier IC 5, which supplies the monolithic multilayer actuator 1 via the contact 6. The LED multichip module 11 is supplied with the generated voltage from the coil connections 10. Since most of the heat loss is generated by the LED multichip module 11, a heat conductor 16 is provided for better heat dissipation and distribution. The housing 18 is metallized on the inside, in the radiation region of the LED multichip module 11, and is designed as a reflector 19. A transparent cap 20, which can be made of both synthetic and mineral glass, ensures the hermetic closure of the LED lamp.

The functional sequences during the conversion of the voltage have already been explained in detail in the description of FIG. 1 - representation of the principle of action.

Figure 3 shows again in an idealized form the current-voltage sequence at the multilayer actuator 1 and makes it clear why the product of current and voltage results in zero. In real terms, a monolithic multilayer actuator 1 has a loss factor of tan δ = 0.05 ... 0.08, which corresponds to the ratio of power loss to reactive power.

FIG. 4 shows the basic circuit structure of the integrated two-pulse voltage rectifier IC 5. The rectification of the voltage takes place via the diodes D of the control bridge, and during the voltage rise the charging current flows into the monolithic multilayer actuator 1 via the diodes D. ten thyristors Th, which are network-controlled, the discharge current of the monolithic multilayer actuator 1 is fed back into the supply network during the drop in voltage. A control bridge based on MOSFETs is also possible.

The LED lamp according to this invention can also be brought into a compact housing with a standard base which is compatible in terms of its construction, even with greater light intensity. Miniaturization according to the desired light output is also possible. The simple and modular design of the LED lamp creates favorable conditions for automated mass production. Since the piezo multi-layer actuator only has a capacitive load on the power supply network, the active power consumed is correspondingly small, which is a cost advantage for the user.

Reference:

IM solid state voltage converter DE 10025 028 A1 121 converter JP 08162689 A

Literature:

CeramTec: Piezoelectric components

(Company lettering with list of literature - piezoceramic, basics, applications), CeramTec

AG, run

Physik Instrumente (Pl) GmbH & Co., Waldbronn: Fundamentals of piezoelectric positioning technology (company lettering)

Göran Engdahl: Handbook of Giant Magnetostrictive Materials Academic Press, ISBN 0-12-238640-X

Legend

1 monolithic multilayer actuator

2 magnetoelastic core

3 isolator

4 spool

5 two-pulse voltage rectifier IC

6 contacting

7 insulator plate

8.1 Base contact 1

8.2 Base contact 2

9 chip connection

10 coil connection

11 LED multichip module

12 flow guide plate

13 permanent magnet

14 Piezo holder

15 Magnet holder

16 heat conductors

17 cooling fins

18 housing

19 reflector

20 transparent cap

21 slot

22 fine threads

Claims

claims

1. LED lamp, consisting of an electromechanical transducer, an insulator and a magnetomechanical transducer, which is composed of a magnetically restrictive core and the coil surrounding it, including a magnetic circuit, the transducer elements being arranged one behind the other in the axial direction and in a mechanical holder are firmly connected, characterized in that

- That the electromechanical converter consists of a monolithic multilayer actuator (1),

- That the insulator (3) and the insulator plate (7) consist of ceramic or a glass-like material,

- That the magnetoelastic core (2) consists of a positive supermagnetostrictive material,

- that there is thermomechanical temperature compensation,

- That a two-pulse voltage rectifier circuit (5) is integrated in the form of a chip and

- That an LED multichip module (11) is used in chip-on-board technology.

2. LED lamp according to claim 1, characterized in

that the monolithic multi-layer actuator (1) is operated with a rectified mains voltage, whereby it expands and contracts again in accordance with the sinusoidal profile of the mains voltage,

- That the magnetoelastic core is thereby compressed and relieved and

- That the coil (4) which surrounds the magnetoelastic core (2) generates a voltage by compressing and relieving the magnetoelastic core (2).

3. LED lamp according to claim 1 and 2, characterized in that the two-pulse voltage rectifier IC (5) allows a charging current and an oppositely flowing discharge current to the monolithic multilayer actuator (1), so that the unconverted and still in the form of charge Energy flows back into the supply network.

4. LED lamp according to claim 1 and 2, characterized in that the monolithic multilayer actuator (1) is designed for a rectified sinusoidal voltage with an effective value of 115V or 230V or a peak voltage of + 180V or + 360V.

5. LED lamp according to claim 1, characterized in that the monolithic multilayer actuator (1) is designed for a sinusoidal AC voltage with an effective value of 115V or 230V or a peak voltage of ± 180V or + 360V.

6. LED lamp according to claim 1, characterized in that the mechanical holder of the functional elements is designed as a hollow cylinder construction, that the mechanical bias via the screw connection with fine thread (22) of the piezo holder (14) and the magnet holder ( 15) is generated and - that in the area of the magnetomechanical transducer a slot (21) is made in the longitudinal direction in the cylindrical magnet holder (15).

7. LED lamp according to claim 1, 4, 5 and 6, characterized in that a permanent magnet (13) is introduced into the magnetic circuit of the electromechanical transducer in order to premagnetize the magnetoelastic core (2).

8. LED lamp according to claim 1 and 6, characterized in that the mechanical holder for thermomechanical temperature compensation consists of an alloy or a composite material with adapted thermal elongation.

9. LED lamp according to claim 1 and 6, characterized in that a bimetal is used for thermomechanical temperature compensation.

10. LED lamp according to claim 1, characterized in that the functional elements, including extremely dry air, are accommodated in a hermetically sealed housing.

1. LED lamp according to claim 1, characterized in that a heat conducting medium is introduced to dissipate the heat loss.