DE102009022070A1 - Circuit and lamp comprising the circuit - Google Patents

Abstract

The invention relates to a circuit, in particular for controlling at least one semiconductor light-emitting element, comprising a series circuit having at least one first semiconductor light-emitting element and at least one second semiconductor light-emitting element, wherein a control component is provided for the at least one second semiconductor light-emitting element. Furthermore, a lamp comprising such a circuit is proposed.

Description

The The invention relates to a circuit, in particular for operation or for driving a lamp and a lamp with such Circuit.

It There are lamps with semiconductor light elements that have a high color rendering index should have. Accordingly, it is desirable that such Lamp over time or at changing temperatures the given Color location and the color rendering index not changed if possible. It Phosphorus mixtures are known which have a high color rendering index but their efficiency is comparatively low.

The The object of the invention is the disadvantages mentioned above and in particular an efficient and cost effective option to create an at least largely constant color locus and color rendering index to allow a lamp.

These Task is performed according to the characteristics of independent claims solved. Further developments of the invention will become apparent from the dependent claims.

• – umfassend eine Reihenschaltung mit mindestens einem ersten Halbleiterleuchtelement und mit mindestens einem zweiten Halbleiterleuchtelement,
• – wobei eine Steuerkomponente für das mindestens eine zweite Halbleiterleuchtelement vorgesehen ist.

To achieve the object, a circuit, in particular for controlling at least one semiconductor element, is specified

• Comprising a series connection with at least one first semiconductor light-emitting element and with at least one second semiconductor light-emitting element,
• - Wherein a control component is provided for the at least one second semiconductor element.

Based the engine for the at least one second semiconductor light-emitting element can in particular a current through the at least one second semiconductor element (largely) independent from a current through the at least one first semiconductor light-emitting element changed become. This makes it possible that the color location and the color reproduction of the semiconductor light elements can be kept largely constant or according to a Default is adjustable. A lamp with such a circuit thus has a largely constant color locus and color rendering index on.

The At least one first semiconductor element has, for example a wavelength converting Phosphor, for example, based on grenades such as YAG: Ce, on. Such a semiconductor element can, for example, be yellowish, greenish, blue-greenish or reddish Emit light.

A Further development is that the first semiconductor element white light emitted.

A Another development is that the second semiconductor element white Emitted light.

Especially It is a development that the first semiconductor element and the second semiconductor light emitting element emit different white light.

Consequently can Semiconductor lighting elements may be provided, the z. B. cold white light and / or warm white Emit light.

Also It is a development that the second semiconductor element emitted red light.

Especially At least one such second semiconductor light-emitting element can be provided. By mixing red light with white light can be a desired Color locus can be set at a high color rendering index.

Further It is a development that a variety of first semiconductor light elements and a second semiconductor light-emitting element are provided.

Consequently can a z. B. be provided red semiconductor element, the with several white semiconductor elements is connected in series.

in this connection It should be noted that the semiconductor light-emitting element is a light-emitting diode (LED) can be.

in the Framework of an additional Continuing, the control component is at least one changeable Resistor, which is to the at least one second semiconductor element is connected in parallel.

A next Further development is that the variable resistor is a PTC thermistor or a thermistor or a potentiometer or at least one of these components includes.

A Embodiment is that the control component a current control for modifying a current through the at least one second semiconductor element.

A alternative embodiment is that the control component to a current control for Modification of a current through the at least one first semiconductor element having.

Accordingly, based on the control component of the current through the at least one second semiconductor element and / or by the mindes at least one first semiconductor element is influenced, in particular adjusted or regulated.

A next Embodiment is that the current of the current control based on a Color sensor and / or a brightness sensor and / or a temperature sensor is adjustable.

Also It is an embodiment that uses the current of the current regulation a temperature sensor is adjustable.

A Training is that the current of the current control based a microcontroller is adjustable.

Especially can the microcontroller for controlling an electrical switch, z. B. a transistor, a MOSFET, an IGBT o. Ä. Are used, so that z. B. dependent from a signal from a color, brightness or temperature sensor the current at least through the at least one second semiconductor element can be influenced or regulated.

Also Is it possible, that the signal of the color, brightness or temperature sensor for Actuation of the electrical switch (as described above) is being used.

A Another embodiment is that the control component a Unit for pulse width modulation has.

The The above object is also achieved by a lamp comprising a circuit as described herein.

The In particular, the lamp can have a plurality of (first and second) semiconductor light-emitting elements and in the form of a lamp, a lighting system or a be realized other lighting unit.

embodiments The invention are illustrated below with reference to the drawings and explained.

It demonstrate:

1 a circuit comprising a group of white semiconductor luminescent elements connected in series with each other and with a red semiconductor luminescent element, a control component being provided in parallel with the red semiconductor luminescent element for adjusting a current through the red semiconductor luminescent element;

2 a circuit for mixing white and red light, unlike the circuit of 1 an electronic switch is provided for adjusting the current through the red semiconductor light-emitting element;

3 an alternative circuit too 1 wherein the control component comprises a potentiometer;

4 a circuit for mixing white and red light, wherein a control component is provided in the form of a voltage divider;

5 an alternative circuit in which a voltage divider serves to drive a Mosfets;

6 another circuit with a PWM generator for driving an electronic switch, z. B. in the form of a transistor.

It a mixing concept is proposed by semiconductor elements, wherein first semiconductor light elements preferably as white LEDs accomplished and at least one second semiconductor element as at least a different color, z. B. red, LED is executed. The following is an example assumed that the at least one second semiconductor element a red LED is. Naturally can also several red LEDs or several differently colored LEDs as second Semiconductor lighting elements may be provided.

For the least a red LED is a control component provided, at least affects a current through the at least one red LED. optional the control component can also control the flow through the at least one influence first semiconductor element. In particular, the streams through the first semiconductor element and / or through the second Semiconductor lighting element independent or dependent be adjustable from each other.

For example, the control component may include a resistor, wherein the resistor may be implemented as a temperature-dependent resistor. For example, in this case at least one thermistor or at least one PTC thermistor can be used. It is also possible, the control component as an electrical switch, for. B. a transistor or MOSFET, which receives a signal via a color sensor and / or a brightness sensor and / or a temperature sensor and controls the current through the at least one red LED depending on this signal. Alternatively, it is possible that the electronic switch is controlled by a microcontroller. Optionally, a resistor may be provided, which is designed as a potentiometer. Also, a voltage divider (comprising ohmic and / or variable resistors) can be connected in parallel to the semiconductor light elements be ordered and the current through the semiconductor light elements can be influenced via the voltage divider.

The several white ones Light-emitting diodes and the at least one red light-emitting diode are preferably connected to one another connected in series. In particular, different numbers of white Light emitting diodes and / or different numbers of red LEDs be provided. For example, at least one white light-emitting diode provided with at least one further white light emitting diode be, both white LEDs have different shades (eg "warm white", "cool white").

Instead of the at least one red LED can also at least one different colored light emitting diode or in addition to the red light emitting diode can also be provided a different colored light emitting diode. Basically it is possible a first group of LEDs of one color with a second group of LEDs with a different color in series.

A Another alternative is that the engine has a Voltage divider includes, by means of which voltages above the first group of light emitting diodes as well as over the second group of LEDs are adjustable. Such a voltage divider can also combined with the above-mentioned electrical switch in particular, can the resistances temperature-dependent or as a potentiometer be.

The Number of red and white LEDs to be connected in series may vary Requirement changed become.

Of the presented approach has the advantage that different Aging of diverse semiconductor light elements efficiently can be corrected. In this respect, a lamp with several semiconductor light elements appears for the User extremely color-stable.

One Another advantage is that due to the proposed Engine a highly efficient Regulation possible is, d. h., That the light output compared to other solutions significantly is higher. It is advantageous that only a single power source needed (otherwise two sources of power will be used to create two colors required).

1 shows a group of semiconductor light elements 104 comprising three white light-emitting diodes 101 . 102 and 103 which are connected in series with each other. The group of the first semiconductor light elements 104 is still with a red LED 105 connected in series. Parallel to the LED 105 is a control component 106 provided, which exemplifies a resistor 107 having. At the series connection of the group of semiconductor light elements 104 and the red LED 105 in parallel with the control component 106 is a DC voltage, indicated by connections 108 and 109 , at.

The resistance 107 may be one or more ohmic resistors, PTC (PTC thermistor) or NTC (thermistor) or combinations thereof. By means of the control component 106 can about the resistance 107 the red LED 105 another current is impressed than the group of first semiconductor light elements 104 , Particularly advantageous is the control component 106 changeable (eg as PTC, NTC), allowing an efficient adjustment of the red LED 105 depending on the variable controlled variable (eg from the temperature) can take place.

2 shows a group of semiconductor light elements 204 , the example of two white LEDs 201 and 202 having. The two LEDs 201 and 202 are connected in series and arranged in series with a parallel connection of a red LED 205 and a control component 206 , The engine 206 has an electronic switch 207 (here embodied as an n-channel MOSFET) whose gate terminal is via a signal 203 can be controlled. The series connection of the group of semiconductor light elements 204 and the parallel connection of the red LED 205 and the control component 206 is to a DC voltage source or a DC power source, indicated by connections 208 and 209 , connected.

The drive signal 203 may for example come from a brightness sensor or a color sensor, from a temperature sensor or from a microcontroller or combinations thereof and a current flow through the red light emitting diode 205 influence or control. Accordingly, a brightness component of the red light emitting diode 205 in relation to a brightness component of the white LEDs 201 . 202 by means of the control component 206 be kept almost constant and thus high color stability of the entire arrangement comprising the LEDs 201 . 202 and 205 be achieved.

3 shows a similar arrangement 1 that is, a group of semiconductor light elements 304 comprising three white light-emitting diodes 301 . 302 and 303 which are connected in series with each other. The group of the first semiconductor light elements 304 is still with a red LED 305 connected in series. Parallel to the LED 305 is a control component 306 intended. At the Series connection of the group of semiconductor light elements 304 and the red LED 305 in parallel with the control component 306 is a DC voltage, indicated by connections 308 and 309 , at.

The engine 306 includes instead of in 1 shown resistance 107 a potentiometer 307 , In this respect, via the potentiometer, the current through the red LED 305 in proportion to the current through the white LEDs 301 to 303 to be changed.

4 shows a circuit comprising a group of semiconductor light elements 404 as white light emitting diodes connected in series 401 to 403 , wherein parallel to the group of semiconductor light elements 404 a resistance 410 is arranged. Furthermore, a red LED is provided 405 , to the parallel a resistance 407 is arranged, this parallel circuit of red light emitting diode 405 and resistance 407 in series with the group of semiconductor light elements 404 in parallel with the resistor 410 is arranged. Furthermore, a DC voltage indicated by connections 408 and 409 intended for operation of the arrangement.

The proportion of the circuit comprising the resistors 410 and 407 are as a tax component 406 summarized. Thus, the control component includes 406 a voltage divider for adjusting a voltage ratio across the group of semiconductor light elements 404 in relation to the red LED 405 , The resistors 407 and 410 can be made both or partially variable. For example, it is possible that at least one resistor as a temperature-dependent resistor, for. B. designed as a thermistor or as a PTC thermistor is. In particular, both resistors can be designed as a thermistor and / or a thermistor.

5 shows a group of semiconductor light elements 504 comprising a series connection of two white LEDs 501 and 502 where the group of semiconductor light elements 504 connected in series with a red LED 505 , The series connection of the group of semiconductor light elements and the red light emitting diode 505 is with a voltage, indicated by connections 508 and 509 , provided.

Furthermore, a control component 506 provided, on the one hand via a series circuit of a resistor 510 and a resistance 503 with the connections 508 and 509 the power supply is connected, wherein the center tap of this series circuit of the resistors 510 and 503 to the gate terminal of a transistor, such as an n-channel MOSFET 507 connected is. The source terminal of the MOSFET 507 is with the connection 509 connected to the power supply and the drain terminal of the MOSFET 507 is with the center tap between the group of semiconductor light elements 504 and the red LED 505 connected.

Again, the resistors 503 and 510 be executed at least partially as a variable resistors.

6 shows a circuit with an alternative embodiment for driving a white LED 601 and a red LED 602 , Instead of the white LED 601 several white LEDs can be provided. Also, instead of the red LED 602 several red LEDs may be provided.

A power source 607 is over their connections 608 and 609 with a series circuit comprising the white LED 601 and the red LED 602 connected. The center tap of the series connection is connected to the collector of a transistor 603 , z. B. an n-channel MOSFET, its emitter connected to the terminal 609 the power source 607 connected is. Furthermore, a PWM generator 606 provided for driving the base of the transistor 603 , The PWM generator is connected to the connector 609 connected to the power source and is over a temperature-dependent resistor 604 , which is designed, for example, as an NTC resistor, driven. For this purpose, a voltage divider of a series circuit comprising a resistor 605 and the resistance 604 provided with the connections 608 and 609 the power source is connected. The center tap of this series connection of the resistors 605 . 604 is with the PWM generator 606 connected. As a PWM generator 606 For example, an integrated circuit of type NE556 can be used.

101

led (eg white)

102

led (eg white)

103

led (eg white)

104

group from (white) LEDs

105

led (eg red)

106

control component

107

resistance

108

connection the power supply

109

connection the power supply

201

led (eg white)

202

led (eg white)

203

control signal

204

group from (white) LEDs

205

led (eg red)

206

control component

207

n-channel MOSFET

208

connection the power supply

209

connection the power supply

301

led (eg white)

302

led (eg white)

303

led (eg white)

304

group from (white) LEDs

305

led (eg red)

306

control component

307

variable Resistance (potentiometer)

308

connection the power supply

309

connection the power supply

401

led (eg white)

402

led (eg white)

403

led (eg white)

404

group from (white) LEDs

405

led (eg red)

406

control component

407

resistance

408

connection the power supply

409

connection the power supply

410

resistance

501

led (eg white)

502

led (eg white)

503

resistance

504

group from (white) LEDs

505

led (eg red)

506

control component

507

n-channel MOSFET

508

connection the power supply

509

connection the power supply

601

led (eg white)

602

led (eg red)

603

npn transistor

604

NTC resistor

605

resistance

606

PWM generator

607

power source

608

Connection of the power source 607

609

Connection of the power source 607

Claims (15)

Circuit, comprising a series connection with at least one first semiconductor light-emitting element ( 101 . 102 . 103 ) and with at least one second semiconductor element ( 105 ), - where a control component ( 106 ) for the at least one second semiconductor element ( 105 ) is provided. A circuit according to claim 1, wherein the first semiconductor element ( 101 . 102 . 103 ) emits white light. Circuit according to one of the preceding claims, in the second semiconductor element emits white light. Circuit according to one of the preceding claims, in the first semiconductor light-emitting element and the second semiconductor light-emitting element different white Emit light. Circuit according to one of the preceding claims, in which the second semiconductor element ( 105 ) emits red light. Circuit according to one of the preceding claims, in which a plurality ( 104 ) of first semiconductor light elements and a second semiconductor light element ( 105 ) are provided. Circuit according to one of the preceding claims, in which the control component has at least one variable resistor ( 107 . 307 ) which is connected to the at least one second semiconductor element ( 105 . 305 ) is connected in parallel. The circuit of claim 7, wherein the variable Resistor a PTC thermistor or a thermistor or a potentiometer or comprises at least one of these components. Circuit according to one of the preceding claims, in the control component has a current control for modification a current through the at least one second semiconductor element. A circuit according to claim 9, wherein the control component a current control for modifying a current through the at least comprises a first semiconductor element. A circuit according to any one of claims 9 or 10, wherein the Current control current using a color sensor and / or a Brightness sensor is adjustable. Circuit according to one of the preceding claims, in the current of the current regulation can be set by means of a temperature sensor is. Circuit according to one of the preceding claims, in the current of the current control using a microcontroller adjustable is. Circuit according to one of the preceding claims, in which the control component is a pulse width modulation unit ( 606 ) having. A lamp comprising the circuit according to a of the preceding claims.