WO2007106043A1

WO2007106043A1 - Integrated hid ballast system

Info

Publication number: WO2007106043A1
Application number: PCT/SG2006/000128
Authority: WO
Inventors: Hang Siang Heah; Nazem Alireza
Original assignee: Wana Lights Sdn Bhd (Co. No. 716214-V); Pintas Pte Ltd
Priority date: 2006-03-14
Filing date: 2006-05-19
Publication date: 2007-09-20

Abstract

An integrated ballast module (200) for activating a High Intensity Discharge (HID) light bulb (30), which comprises an activation signal receiving means (60), an activation signal adapting means (212) comprising a multi-polarity circuit which accept the polarity of the incoming activation signal current, a process controller (204), a receiving means (40) for input power, a delayed switching means (206), a switch-mode power supply (SMPS) section (208), a converting and filtering section (210) and a transmitting means (50) for output power wherein a light activation command signal received through the activation signal receiving means (60) is adapted and sent to the process controller (204) which starts the delayed switching means (206) and the generating of AC current by the SMPS (208) to be transmitted to one or more HID light bulbs (30). Additionally the module contains a circuitry design to diagnose problems encountered in the ballast module (200) installation and operation such as faulty input connections, low battery, faulty bulb and faulty output connections.

Description

INTEGRATED HID BALLAST SYSTEM

FIELD OF THE INVENTION

The present invention relates to an electronic ballast system used in High Intensity Discharge (HID) lights. More particularly, the present invention relates to an electronic ballast system used for the HID headlights in the vehicle industry.

BACKGROUND ART

High Intensity Discharge (HID) refers to lighting technology that relies on an electrical discharge to arc the compound of substances in a sealed bulb. HID lamps produce light by striking an electrical arc across two electrodes housed inside a specially designed inner fused quartz or fused alumina tube filled with Xenon gas. The gas aids in the starting of the lamps.

HID lighting in vehicles improves durability compared to Halogen bulb as road vibrations and chemical reactions between substances can cause damage to the halogen filament. These light sources produce a wide domain of colour temperature lighting that is safer because it is akin to natural daylight. The domain of colour temperature varies from 4000K to 20,000K. The HID system will also consume much less power thus generating less heat resulting in more brightness and better efficiency.

Like fluorescent lamps, HID lamps require a ballast to start and maintain their operation. FIGl illustrates the currently used method of operation for a vehicle HID headlight. Once the driver activates the HID switch (10) from his position, a small electrical signal is sent to an external relay switch (100).

The operation of the external relay switch (100) is shown more clearly in FIG 2. Its function is to utilise the small electrical signal current from the driver switch (10) to activate another switch which will enable the flow of a much larger current, 30-40A, from the vehicle battery to the adaptor section (102). The polarity of the common pin is set differently in different car models. Even among the H4 connection standard vehicles, the common pins differ according to the model and manufacturer. The function of the adaptor (102) is to send the electrical current with correct polarity to the HID ballast. As shown in FIG 3, the adaptor comes in two types, depending on the common polarity of the specific car model. Due to the large current received from the external relay switch, a couple of power diodes are employed to adapt the switching signal into the correct polarity before being sent to the conventional ballasts (104). The power diodes are heavy duty and comparatively large which increases the cost and causes voltage loss and heat dissipation across the power diodes.

The ballast (104) is a type of transformer that serves to start a fluorescent or HID bulb by causing an arc to form inside the bulb. Once the bulb is ignited, the current flowing through the bulb must be regulated to keep the arc operating at peak efficiency. The ballast can be of a magnetic type or an electronic type, the latter able to change the frequency of the electrical current.

The electrical current from the ballast (104) will then ignite the HID bulb. A separate electronic ignitor circuit might also be employed between the ballast section (104) and the HID bulb.

As such, HID lights are more complex than normal bulbs. They come with ballasts, gas bulbs, and custom wiring. The ballast and ignition systems currently available in the market for the HID lighting, particularly for usage in vehicles, are bulky and generally costlier due to the expensive diodes and relays contained within them. The custom wirings required to install them also adds significantly to the cost.

Therefore there exists a need for a ballast system that is much less bulky, cheaper and also easy to install and maintain in vehicles. SUMMARY OF THE INVENTION

Accordingly the present invention provides an integrated ballast module for activating a High Intensity Discharge (HID) light bulb, which comprises an activation signal receiving means, an activation signal adapting means comprising a multi-polarity circuit which accept the polarity of the incoming activation signal current, a process controller, a receiving means for input power, a delayed switching means, a switch-mode power supply (SMPS) section, a converting and filtering section and a transmitting means for output power wherein a light activation command signal received through the activation signal receiving means is adapted and sent to the process controller which starts the delayed switching means and the generating of AC current by the SMPS to be transmitted to one or more HID light bulbs.

Additionally the module contains a circuitry design to diagnose problems encountered in the ballast module installation and operation such as faulty input connections, low battery, faulty bulb and faulty output connections.

The present invention consists of certain novel features and a combination of parts hereinafter fully described and illustrated in the accompanying drawings and particularly pointed out in the appended claims; it being understood that various changes in the details may be without departing from the scope of the invention or sacrificing any of the advantages of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of facilitating an understanding of the invention, there is illustrated in the accompanying drawings the preferred embodiments from an inspection of which when considered in connection with the following description, the invention, its construction and operation and many of its advantages would be readily understood and acknowledged.

FIG. 1 is a schematic of the HID systems of the prior art.

FIG. 2 is a circuit diagram of the relay and ballast control in the prior art.

FIG. 3 shows the polarity adaptor in the prior art.

FIG. 4 is a schematic of the Integrated HID Ballast.

FIG. 5 is a circuit diagram of the relay and ballast control in the present invention.

FIG. 6 shows the polarity adaptor in the present invention.

FIG.7 is a top view of the present invention.

FIG.8 is the 3-dimensional view of the preferred embodiment of the present invention.

FIG.9 lists the functions of the Condition Indicator as programmed in the MCU.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to an electronic ballast system used in High Intensity

Discharge (HID) lights. More particularly, the present invention relates to an electronic ballast system used for the HID headlights in the vehicle industry. Hereinafter, the

Integrated HID Ballast System shall be described according to the preferred embodiments of the present invention and by referring to the accompanying description and drawings.

However, it is to be understood that limiting the description to the preferred embodiments of the invention and to the drawings is merely to facilitate discussion of the present invention and it is envisioned that those skilled in the art may devise various modifications without departing from the scope of the appended claim.

The existing HID ballast systems, as shown in FIG 1 and described in the background art, consists of a large external relay switch, an adaptor for the light switching control and finally a ballast. All three are separate and bulky components. Furthermore voltage loss and heat dissipation occurs across the power diodes in the adaptor.

The present invention takes a novel and inventive approach to the problems faced by the existing ballast systems. FIG. 4 shows the present invention, wherein the separate modules between DC power source (20) and the HID Xenon bulb (30) are simplified into an integrated ballast system (200). It does away with the need for an external relay kit and also the different adaptors needed in different models of cars.

System Operation In the present invention, when the driver activates the headlight switch (20), the small current from the said switch does not go to the external relay switch directly as in the prior art. Instead, the signal current is passed through a Smart Input Control (SIC). The SIC (202) adapts the small signal current to the correct polarity and sends it to the Controller (204).

The Controller (204) is a microcomputer unit (MCU), although an Integrated Circuit (IC) can be substituted if diagnostic functions are not required. The controller (204) activates the soft-start relay switch and also provides pulse-width modulated signal (PWM) to the switch- mode power-supply (SMPS).

With the soft start circuitry (206), the armature in the relay kit solenoid does not move to permit the flow of the main current until the right voltage is reached within the input capacitor therefore igniting the HID light sufficiently; usually within 50-200ms. The soft- start relay drastically reduces the surge current from the 30-40A in the conventional HID ballast systems to just 6- 1OA. Not only does this reduce the size of the relay kit but it also enables the relay-kit, along with the soft-start circuit to be built into the ballast compartment (200). The soft-start relay switch (206) can be either an electromechanical relay switch or a semiconductor with a similar function; namely to act as a relay switch for the main current.

After the soft-start relay switch activates, the current flows to the SMPS (208), which is operated by the PWM signals emitted by the Controller (204). The SMPS converts the DC current from the battery (20) to a square wave current of high-frequency. This modified power current is sent to the converting and filtering section (210).

The converting and filtering section (210) converts and smooths the incoming square- wave current to a sinusoidal high-voltage AC current. Thereafter this high-voltage AC current with high frequency is transmitted to operate the HID bulb (30).

Smart Input Control (SIO

As mentioned, the common polarity of the switching mechanism in H4 connection standard differs according to vehicle models and has conventionally required different adaptors. The present invention overcomes the need for the different adaptors with heavy-duty power diodes by the use of a smart input controller (SIC). The SIC (202) comprises six bridged diodes and a transistor, as shown in FIG 6.

The trigger switch control pins carrying the current from the driver switch can be connected to either two of Pl, P2 or P3. For example, Pl can connect to low-beam signal, P2 to high- beam signal and P3 to the common/base polarity. Regardless of the polarity, the correct polarity of the current will reach the base/gate of the transistor in the SIC (202) and therein induce a flow of a polarity of current through the emitter/source of the transistor that is acceptable to the Controller (204). This circuitry eliminates the need for different adaptors and the power diodes contained within the said adaptors. The SIC (202) is much smaller and can be in-built within the ballast compartment (200), as shown in FIG 1 and FIG 7. Another function of the SIC (202) is as an OR-gate. Due to the wide preference in the usage of H4 lighting standard to have both low and high beam in one halogen bulb with two individual filaments, the driver is only able to have either high or low beam since the operation of both beams simultaneously will overheat and melt the bulb. However, HID lighting combinations will not generate such an amount of heat. As such, customers installing HID headlights prefer to have the low-beam HID lights active even when switched to high-beam. This requires an OR-gate.

Conventionally, such an OR-gate has to be installed and set-up externally using a set of heavy-duty diodes. The SIC (202) combines the OR-gate with the trigger port control pins thus eliminating such a costly set-up. As shown in FIG 6, regardless of whether a signal is received through the points PI or P2, and regardless of their polarity, the HID Ballast will be activated.

Microcomputer Unit (MCTJ)

One of the functions of the MCU is as an Integrated Circuit (IC) to control the soft-start relay switch and the SMPS (208) with inverter functoin. In fact, the MCU (204) can indeed be replaced by an IC with such functions without affecting the basic HID lighting operation.

However, with the important parts of the ballast system (200) - such as the input port and relay switch - built within the present embodiment, it becomes possible and also desirable to set up a differential diagnosis system using a programmed MCU. As shown in FIG 4, the MCU is able to gather feedbacks from the relay switching section (206), SMPS section (208) and also the converting and filtering section (210). Using the information in the feedback, the MCU is able to detect various problems found in the entire system within the vehicle that affects the operation of the HID lightings. A Condition Indicator (212) controlled by the MCU (204) indicates any problem diagnosed by the said MCU through an LED light. FIG. 9 lists the diagnostic functions of the MCU and also the resultant Indicator (212) activity to indicate the respective problems as detected by the MCU (204).

Integrated Ballast Module

With the introduction of the SIC (60) and the built-in soft-start relay switch (206), bulky components such as the external relay kit and adaptors with power diodes are eliminated and are instead built into the ballast module itself.

The resultant integrated ballast module (200) can be seen in FIG 7 and FIG 8. The module has three ports, namely a trigger port (60) to receive command signals from the driver switch (10), an input port (40) to receive DC power from the battery and and an output port (50) to send high-voltage AC current to the HID bulb (30). Additionally, the diagnostics provided by the MCU (204) through the LED (212) makes the system even more easier to set-up correctly with minimum training.

While in the foregoing specification this invention has been described in relation to certain preferred embodiments thereof and many details have been set forth for purpose of illustration, it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments and that certain of the details described herein can be varied considerably without departing from the basic principles of the invention.

Claims

1. An integrated ballast module (200) for activating a High Intensity Discharge (HID) light bulb (30), which comprises: ^' a. an activation signal receiving means (60); b. an activation signal adapting means (202) comprising a multi-polarity circuit which accept the polarity of the incoming activation signal current; c. a process controller (204); d. a receiving means (40) for input power; e. a delayed switching means (206); f. a switch-mode power supply (SMPS) section (208); g. a converting and filtering section (210); h. a transmitting means (50) for output power; wherein, a light activation command signal is received through the activation signal receiving means (60) and is processed by the activation signal adapting means (202) and sent to the process controller (204), said process controller starts the delayed switching means (206), the said delayed switching means permits the flow of current from a power source (20) through the receiving means (40) for input power into the SMPS section (208), wherein the SMPS section generates an electrical current, said electrical current converted and filtered by the converting and filtering section (210) and thereafter transmitted through the transmitting means (50) for output power to one or more HID light bulbs (30).

2. A ballast module (200) as in Claim 1, wherein: the receiving means for input power is an input port (40) in the module; the transmitting means for output power is an output port (50) in the module; and the activation signal receiving means is an activation port (60) in the module consisting of one or more trigger pin(s).

3. A ballast module (200) as in Claim 2, wherein the activation port (60) is combined with any one of the input (40) or output port (50).

4. A ballast module (200) as in Claim 1, wherein the delayed switching means (206) is either one of an electromechanical or semiconductor type.

5. A ballast module (200) as in Claim 1, wherein the activation port (60) uses one or more couples of bridged diodes and a transistor; wherein the signal current rectified through the diodes is used to induct the transistor to pass a current through the said transistor, the said passing current having the polarity required by the process controller (204).

6. A ballast module (200) as in Claim 5, wherein two or more couples of the bridged diodes act as an OR-gate to enable the use of both high beam filament bulb and low beam HID bulb (30) when the high-beam in a vehicle is switched on.

7. A ballast module (200) as in Claim 1, wherein the process controller (204) is an Integrated Circuit (IC) or HID controller providing pulses to the SMPS (208).

8. A ballast module (200) as in Claim 1, wherein the. process controller (204) is a programmed Microcomputer Unit (MCU) providing pulses to the SMPS (208).

9. A ballast module (200) as in Claim 8, wherein the module contains a circuitry design to diagnose problems encountered in the ballast module (200) installation and operation.

10. A ballast module (200) as in Claim 8, wherein the diagnosis results of the said circuitry design is displayed by an indicator (212) in the ballast module (200).

11. A ballast module (200) as in Claim 8, wherein the diagnostics of the said circuitry design comprises: a. faulty input connections; b. low battery; c. faulty bulb; d. faulty output connections; e. normal operation;