What Is an Electronic Ballast?

Electronic ballast (Electronic ballast) is a kind of ballast. It refers to the electronic equipment that uses electronic technology to drive the electric light source to produce the required lighting. Corresponding to it is an inductive ballast (or ballast). More and more modern fluorescent lamps use electronic ballasts, which are light and compact, and can even integrate electronic ballasts with lamp tubes. At the same time, electronic ballasts can often have the function of a starter, so it can save Go to the separate starter. Electronic ballasts can also have more functions, such as improving or eliminating the flickering of fluorescent lamps by increasing the current frequency or current waveform (such as turning into a square wave); it can also use a DC power supply for fluorescent lamps through the power inversion process. Some disadvantages of traditional inductive rectifiers are causing them to be replaced by increasingly mature electronic ballasts.

The global energy crisis appeared in the 1970s, and the urgency of saving energy has led many companies to focus on energy-saving light sources and

(1) Energy saving.

Working principle of inductive ballast:

When 220V 50HZ AC power is applied in the switch closing circuit, current flows through the ballast and the lamp filament

The electronic ballast can be divided into 4 series and 15 varieties:

1. One for one, ordinary type and

PF (PowerFactor) power factor

The combination of ballast and lamp for the effective use of power input power is also expressed in some places as Watt / VA or COS. Generally inductive ballast

1. High power factor, power factor> 0.9

2.Lumen coefficient> 95%

3. Working temperature -15 -+ 50

4. The highest temperature rises by 15

5.Working voltage range 160VAC-240VAC

6, product design and processing procedures strictly in accordance with ISO9002

The electronic ballast is directly rectified by the mains power, and then performs half-bridge inverter to light up.

1. One-to-one, one-to-two light box electronic ballast is specially designed for outdoor light boxes and billboards The advantages are as follows:

1) Use high safety insulation performance, good waterproof and moistureproof performance, ballast

Electronic ballast

Duty cycle dimming

This dimming control method uses high frequency

1. The most common failure of fluorescent lamps is that the lamp is not on, and there is no response when the lamp is turned on. First, measure whether R0 is blown. RO itself is a safety feature, once it is overcurrent, it will burn out, so as not to damage more components. Some ballasts connect 0.5A fuses at the RO. If RO blows, there must be overcurrent

The electronic ballast also has the following problems in practical use:

1. Reliability is difficult to guarantee. The circuit structure of electronic ballasts for HID lamps is far more complicated than that of fluorescent ballasts. The number of selected electronic components is several times that of electronic ballasts for fluorescent lamps, and the probability of failure of electronic components is also high. At the same time, China's HID bulb manufacturers are uneven, and the actual implementation standards are different. It is difficult to achieve a true match between the bulb and the electronic ballast, and the effect can be imagined.

2. The working environment is difficult to achieve. The requirements of the electronic ballast for the use environment make new requirements for the design of lamps. such as

1. Maintain a constant output power:

Keep the lamp's instantaneous output power constant. If a square wave current drive is used, the output characteristics of the lamp's instantaneous output power will be constant, thereby ensuring that "acoustic resonance" does not occur.

2. Abnormal protection function:

Electronic ballasts may have abnormal conditions such as lamp leakage, inactivation, non-startup and excessive current in the main circuit during the use with the lamp. In order to avoid damage to the ballast, the lamp will automatically Close the ballast to ensure the safety, performance and reliability of the ballast. 3. Over current and voltage control:

When the power supply quality is not high, various harmonics and noise pollution in the power grid (such as instantaneous high voltage, high energy

Three steps in the development of electronic ballasts: analog-hybrid-digital

Digital electronic ballasts are for analog electronic ballasts. After the electronic ballasts appeared, the ballasts started from the analog type, and the initial circuits were generally analog circuits. Electronic ballasts have a simpler structure and simpler functions. To meet the requirements of standards such as 3C, the construction of the circuit is more complicated, and it is not easy to achieve warm-up start, Cut-off and other protection functions; if these can be achieved Functional analog electronics face greater difficulties in product consistency and reliability and are not easily solved. However, ordinary analog electronics have the advantage of cost. They have played a very important role in the marketization process of electronic ballasts replacing inductive ballasts, and they are still the most widely used product in the market.

With the development of the market, the user's requirements are getting higher and higher, and the ordinary analog electronic ballast ballasts are gradually changing to digital, so electronic ballasts with mixed digital and analog circuits appear on the market. Front-end analog, rear-end digital, or front-end digital, rear-end analog. These hybrid circuits greatly improve the quality requirements of ordinary analog circuits, and can easily achieve standard performance requirements and reliability requirements, which is also a good transition choice. , Can meet some of the requirements of a relatively higher market demand, but the cost is higher than analog electronics.

To truly meet the safety requirements, performance requirements, EMI and EMC requirements, and at the same time achieve high product reliability requirements, you must take the road of digital electronic ballasts. Digital circuits with unique high stability, high reliability, and high logic can easily implement the various requirements specified in the standard, such as: wide voltage or even full voltage start (120-277V), program-type warm-up start, abnormal conditions For diagnosis and protection, digital electronic ballasts can truly meet the requirements of national standards and be conveniently applied to various occasions.

Although digital is higher than analog and hybrid electronic ballasts in terms of single cost, from a TOC (total customer cost) perspective, that is, total cost = purchase cost + use cost + maintenance cost, digital electronics The purchase cost of the ballast is high, but its use cost and maintenance cost are greatly reduced. In the end, the total cost (TOC) is still much lower than analog electronic and hybrid electronic ballasts; digital electronic ballasts The device has a quality guarantee of up to 5 years (or more than 20,000 hours), and at the same time greatly exerts the efficiency and service life of the lamp. It is a real value creation for customers and is in line with the country.

HID lamp requirements for ballast and selection of working circuit

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HID lamp is a high pressure discharge

Product definition of electronic ballast

An electronic control device that uses semiconductor electronic components to convert a DC or low-frequency AC voltage into a high-frequency AC voltage to drive a light source such as a low-pressure gas discharge lamp.

Classification of electronic ballasts

Electronic ballasts for fluorescent lamps, electronic ballasts for high-pressure sodium lamps, electronic ballasts for metal halide lamps.

Product characteristics of electronic ballast

1) Energy saving: The power loss of the electronic ballast is only about 40% of the inductive ballast, and the fluorescent lamp will increase the light efficiency by 20% at a high frequency of about 30KHz, and the working current is only about 40% of the inductor. And can start and work under low temperature and low pressure.

2) No flicker: When the lamp is working at about 30KHZ, the light is stable, and the human eye does not feel "strobe", which is good for protecting eyesight.

3) No noise: It is good for working and studying in a quiet environment.

4) Extended lamp life: no starter, no repeated impact, flicker, no premature blackening of the tube, one start, reducing the workload of repairing and replacing the starter and tube

5) High power factor reduces reactive power loss, improves the effective utilization of power supply equipment capacity, and reduces line losses.

Compared with traditional ballast

Compared with traditional inductive ballasts, electronic ballasts

Has the following advantages: 1. Energy saving 2. Improve the performance of ceramic metal halide lamps, so that the lamp (light) is more stable. 3. Perfect protection function The voltage change of the grid has very little effect on the operation of the lamp The impact on the grid is small at startup The potential harm of current harmonics is small

Expansion of electronic ballast content

Comprehensive tester for electronic ballast based on MSP430F133