DE102019110644B4 - Interface module for an energy supply for an LED vehicle headlight with two operating modes - Google Patents

Abstract

Energy supply of an LED vehicle headlight- with a supply voltage connection (Vsup) and- with a reference potential (GND) and- with a voltage converter (BOOST) and- with an output signal (out) of the voltage converter (BOOST) and- with a control signal (1) of voltage converter (BOOST) and- with LED lamps (LED1to LEDn) a lamp wiring and- with an interface module (CTR),- whereby the voltage converter (BOOST) supplies the LED lamps (LED1to LEDn) with electrical energy via its output signal (out). and- wherein the output signal (out) of the voltage converter (BOOST) depends on the state of the control signal (1) and- wherein the interface module (CTR) has a data bus interface (BUS) and- wherein the interface module (CTR) has a controller (CTRL). and- wherein the interface module (CTR) has a first connection (A) and- wherein the interface module (CTR) has a second connection (B) and- wherein the interface module (CTR) has current measuring means (RCTRL) and- wherein the current measuring means (RCTRL) can detect the electric current (ILOAD) flowing through the interface module (CTR) between the first connection (A) and the second connection (B) and- wherein the controller (CTRL) is connected to the first connection (A) and- wherein the interface module (CTR) has a switching means (S), and- wherein the controller (CRTL) has a first operating mode and- wherein the controller (CRTL) has a second operating mode and- the controller (CRTL) has a reference connection (B') and- the lighting means (LED1to LEDn) of the lighting circuit are connected between the second connection (B) and the reference potential (GND) and- the switching means (S) connects the reference connection (B') to a reference potential (GND) when the controller (CRTL) is in the first operating mode and- the switching means (S) connecting the reference connection (B') to a z wide terminal (B) connects when the regulator (CRTL) is in the second operating mode and- wherein the regulator (CRTL) determines the voltage between the first terminal (A) and the reference terminal (B') in the form of a measured value in the first operating mode and- the controller (CRTL) in the second operating mode determining the electrical current between the first connection (A) and the second connection (B) in the form of the measured value using the current measuring device (RCTRL) and- the controller (CRTL) determining the output signal (out) of the voltage converter (BOOST) using the control signal (1) as a function of the measured value determined in this way and- the operating mode being adjustable via the data bus interface (BUS).

Description

generic term

The invention relates to an interface module for supplying energy to an LED vehicle headlight.

General introduction

Automotive customers require system base circuits that include a microcontroller and a booster to power the LED headlights.

1. 1. zum Ersten die Kunden für High-End-Anwendungen komplexe Regelschaltungen zur Steuerung eines Aufwärtswandlers für mehrere separate Geleichspannungswandler vorhalten müssen und
2. 2. zum Zweiten diese Kunden für Low-End-Anwendungen Regelschaltungen vorhalten müssen, die selbst die wesentlichen Funktionen eines solchen Gleichspannungswandlers übernehmen.

Here the problem arises that

1. 1. On the one hand, customers for high-end applications have to provide complex control circuits for controlling a step-up converter for several separate DC-DC converters and
2. 2. Secondly, these customers have to provide control circuits for low-end applications that themselves take on the essential functions of such a DC/DC converter.

From the DE 10 2014 104 548 A1 a circuit for driving one or more LEDs with a controlled compensation element is known. the DE 10 2014 104 548 A1 shows in her 4 a power supply of an LED headlight with a step-up voltage converter (reference number 10 of DE 10 2014 104 548 A1 ) and a controller (reference number 40 of DE 10 2014 104 548 A1 ), a current measuring device (reference number 30 of DE 10 2014 104 548 A1 ), a switching means (reference number 60 of DE 10 2014 104 548 A1 ), which has a reference terminal (reference number 70 of the DE 10 2014 104 548 A1 ) with a reference potential (reference sign GND of DE 10 2014 104 548 A1 ) connects.

From the US 2018 / 0 063 907 A1 is a power supply (reference number 1 of the US 2018 / 0 063 907 A1 ) of a vehicle headlight (reference numeral 100 of US 2018 / 0 063 907 A1 ) with step-up switching converters (reference number 10 of US 2018 / 0 063 907 A1 ), a controller (reference number 30 of US 2018 / 0 063 907 A1 ) and a current measuring device (reference number 40 of US 2018 / 0 063 907 A1 ) and a switching means (reference Q2 of US 2018 / 0 063 907 A1 ) known.

task

The proposal is therefore based on the object of creating a solution that allows the use of the same micro-integrated circuit for both applications and has other advantages.

This object is solved by a device according to claim 1.

solution of the task

A solution with an integrated LED current booster is not flexible enough for the different front light architectures mentioned. It can be used as not in the high-end (high-price segment) as in the low-end (low-price segment) of the market.

The invention therefore provides an interface module that provides a boost converter controller that can be configured to be used to control a constant current in the low-cost headlight segment.

According to the invention, the same interface module can be used to provide a constant voltage in the case of a multi-channel LED headlight, which then interacts with other constant current regulators to supply the LED lamps of the LED headlight with electrical energy.

The invention is explained with the help of the exemplary figures.

The invention thus relates to the energy supply of an LED vehicle headlight. It includes, among other things, a supply voltage connection (V _sup ), a reference potential (GND), a voltage converter (BOOST), an output signal (out) of the voltage converter (BOOST), a control signal (1) of the voltage converter (BOOST), LED lamps (LED ₁ to LED _n ) of a lamp circuit and an interface module (CTR). The voltage converter (BOOST) supplies the LED lamps (LED ₁ to LED _n ) with electrical energy via its output signal (out). The output signal (out) of the voltage converter (BOOST) depends on the status of the control signal (1). The interface module (CTR) has a data bus interface (BUS). The interface module (CTR) has a controller (CTRL), a first connection (A) and a second connection (B) and a current measuring device (R _CTRL ). The current measuring device (R _CTRL ) can measure the current between the first connection (A) and the second connection (B) detect the electric current (IL _OAD ) flowing through the interface module (CTR). The controller (CTRL) is connected to the first connector (A). The interface module (CTR) has a switching means (S). The controller (CTRL) has a first operating mode and a second operating mode. In addition, the controller (CRTL) has a reference connection (B'). The lamps (LED ₁ to LED _n ) of the lamp wiring are switched between the second connection (B) and the reference potential (GND). The switching means (S) electrically connects the reference terminal (B') to a reference potential (GND) when the controller (CRTL) is in the first operating mode and to a reference potential (GND) when the controller (CRTL) is in the first operating mode . The switching means (S) connects the reference terminal (B') to a second terminal (B) when the controller (CRTL) is in the second operating mode. In the first operating mode, the controller (CRTL) determines the voltage between the first connection (A) and the reference connection (B') in the form of a measured value and in the second operating mode the electric current between the first connection (A) and the second connection (B) using the current measuring device (R _CTRL ) in the form of the measured value. The controller (CRTL) regulates the output signal (out) of the voltage converter (BOOST) using the control signal (1) depending on the measured value determined in this way. The operating mode can preferably be set via the data bus interface (BUS), for example by means of an SPI data bus (SPI).

advantage

Such an interface module for the energy supply of an LED vehicle headlight allows, at least in some implementations, a simplification of storage and the use of the same, only differently equipped printed circuits for the electronics of such LED headlights. In particular, such an interface module can be used to supply electrical energy to a number of channels, each with an LED light source interconnection. However, the advantages are not limited to this.

Such an interface module also makes scalable solutions very easy.

character list

• 1 shows a configuration for the low-price segment.
• 2 shows a configuration for the high-price segment.

Description of the figures

figure 1

1 shows a configuration for the low-price segment. The interface module (CTR) has a data bus interface (BUS) that is coupled to the exemplary data bus (SPI). Via this interface (BUS) and the data bus (SPI), the headlight, more precisely the interface module (CTR), receives commands and data from a higher-level computer unit (not shown) or from a user terminal. An internal computer unit (DSP) and an internal logic (logic) process the commands received and, if necessary, change the lighting parameters of the LED lamps (LED ₁ to LED _n ) of the lamp wiring of the headlight. They may also perform various self-tests and/or determine other internal operating parameters. These are either used to readjust the operating parameters of the LED lamps (LED ₁ to LED _n ) of the lamp wiring and/or to transmit them as data to a higher-level computer system (not shown) via the data bus (SPI). In the example of 1 the interface module (CTR) has a controller (CTRL). In the example, this captures the 1 an operating parameter of an exemplary step-up converter as a voltage converter (BOOST). The exemplary step-up converter, the voltage converter (BOOST), consists of an inductance (L _BOOST ), which serves as energy storage, a transistor (T _BOOST ) for preferably periodically connecting the node (K) facing away from the supply side to the reference potential (GND) via a shunt -Resistance (R _BOOST ). A voltage drops across the shunt resistor (R _BOOST ), which is proportional to the current flowing. This voltage can be recorded by the controller (CTR) and used for control purposes. In the example of 1 the controller (CTR) detects this voltage across the shunt resistor (R _BOOST ) by means of a second line (2) and a third line (3). A diode (D _BOOST ) prevents unintentional discharge of the backup capacity (C ₁ ). The LED lamps (LED ₁ to LED _n ) of the lamp wiring draw the load current (I _LOAD ) from the support capacity (C ₁ ). This flows at a first connection (A) in the example 1 into the interface module (CTR). In the example, the load current (I _LOAD ) flows through the 1 the current measuring device (R _CTRL ). In the example of 1 is a shunt resistor that converts the load current (IL _OAD ) into a voltage signal. The load current (IL _OAD ) leaves the interface module (CTR) via the second connection (B) and flows through the LED lamps (LED ₁ to LED _n ) of the lamp wiring. The controller records the signal of the current measuring device (R _CTRL ), here as an example the voltage across the shunt resistance of the current measuring device (R _CTRL ) and thus generates a measured value. Depending on this measured value, the controller (CTRL) then regulates the switching behavior of the transistor (T _BOOST ). As a result, the load current (I _LOAD ) is adjusted to a predefinable constant value. In this second operating mode, the switch (S) connects the reference connection (B'), which preferably provides the reference potential for the voltage measurement by the controller (CTRL), to the second node (B).

Figure2

2 shows an example of the use of the proposed interface module in the high-price segment. The circuit is largely the same as the circuit in FIG 1 . LED lamps (LED ₁ to LED _n ) dder lamp wiring have now been replaced by a plurality of m LED lamp wirings, the m headlight modules (SM ₁ to SM _m ), each of these m headlight modules (SM ₁ to SM _m ) each has its own LED lighting circuitry (LED ₁ to LED _n ) and its own DC voltage converter and/or direct current regulator (external DC/DC). The structure of the m headlight modules (SM ₁ to SM _m ) need not be the same as one another. They can have a different number and connection of LEDs. They can have different voltage and current transformers.

The headlight modules (SM ₁ to SM _m ) are connected to the first connector (A) and not to the second connector (B).

In this first operating mode, the switch (S) connects the reference connection (B'), which preferably provides the reference potential for the voltage measurement by the controller (CTRL), with a reference potential (GND), since the second connection (B) has the current measuring means ( R _CRTL ) is connected to the first terminal (A) essentially without current. The second connection (B) is not connected in this operating mode.

glossary

LED lamp circuitry

An LED lamp circuit can be connected in series and/or in parallel, as well as combinations of such circuits. Those skilled in the art will prefer several LEDs to be connected in series.

Reference List

1

Control signal (1) of the voltage converter (BOOST). The switching state of the transistor (T _BOOST ) of the voltage converter (BOOST) is controlled by the controller (CRT) with the control signal.

A

first connection of the interface module (CRT) and the controller (CTRL);

B

second connection of the interface module (CRT);

B'

Regulator reference pin (CRTL);

BOOST

voltage converter;

BUS

data bus interface;

C1

Support capacity in the voltage converter (BOOST);

crt

interface module. For better understanding, the interface module is shown only schematically and in an extremely simplified manner in the figures.;

CRTL

interface module controller (CRT);

DBOOST

diode in the voltage converter (BOOST);

DSP

computing unit;

ExternalDC/DC

related to the interface module (CTR) of external DC voltage converters or voltage or current regulators;

GND

reference potential;

ILOAD

electrical load current;

LBOOST

voltage converter inductance (BOOST);

LED1

first LED light source of the light source circuit composed of n LED light sources with n as a positive integer;

LEDs

nth LED light source of the light source interconnection from n LED light sources with n as a positive integer;

logic

interface module (CTR) logic circuits;

out

Voltage converter output signal (BOOST);

RBOOST

shunt resistance in the voltage converter (BOOST);

RCTRL

current measuring devices;

S

switching means;

SM1

first headlamp module of m headlamp modules where m is a positive integer;

SMm

mth headlight module of m headlight modules with m as a positive integer;

SPI

data bus, e.g., an SPI data bus;

TBOOST

Transistor of the voltage converter (BOOST);

vs

supply voltage connection;

Claims (1)

Energy supply of an LED vehicle headlight - with a supply voltage connection (V _sup ) and - with a reference potential (GND) and - with a voltage converter (BOOST) and - with an output signal (out) of the voltage converter (BOOST) and - with a control signal (1) of the voltage converter (BOOST) and - with LED lamps (LED ₁ to LED _n ) a lamp circuit and - with an interface module (CTR), - whereby the voltage converter (BOOST) uses its output signal (out) to control the LED lamps (LED ₁ to LED _n ) is supplied with electrical energy and - the output signal (out) of the voltage converter (BOOST) depends on the state of the control signal (1) and - the interface module (CTR) has a data bus interface (BUS) and - the interface module (CTR ) has a controller (CTRL) and - wherein the interface module (CTR) has a first connection (A) and - wherein the interface module (CTR) has a second connection (B) and - wherein the interface module (CTR) has a current measuring device (R _CTRL ) and - wherein the current measuring device (R _CTRL ) has the between the first connection (A) and the second connection (B) through the interface module (CTR) flowing electrical current (IL _OAD ) can detect and - wherein the controller (CTRL) is connected to the first connection (A) and - wherein the interface module (CTR) has a switching means (S), and - wherein the controller (CRTL) has a first Has operating mode and - wherein the regulator (CRTL) has a second operating mode and - wherein the regulator (CRTL) has a reference connection (B') and - wherein the lamps (LED ₁ to LED _n ) of the lamp connection between the second connection (B) and the reference potential (GND) and - the switching means (S) connecting the reference terminal (B') to a reference potential (GND) when the controller (CRTL) is in the first operating mode and - the switching means (S) connects the reference terminal (B') to a second terminal (B) when the regulator (CRTL) is in the second mode of operation and - the regulator (CRTL) in the first mode of operation the voltage between the first terminal (A) and the reference connection (B') in the form of a measured value and - the controller (CRTL) in the second operating mode measuring the electrical current between the first connection (A) and the second connection (B) in the form of the measured value using the current measuring device (R _CTRL ) is determined and - the controller (CRTL) controls the output signal (out) of the voltage converter (BOOST) using the control signal (1) depending on the measured value determined in this way and - the operating mode can be set via the data bus interface (BUS).

Images