The dimming of fluorescent lamps was developed on the basis of high frequency electronic ballasts. Below is the circuit diagram of the high frequency electronic ballast: The working principle is as follows: the power frequency power supply is converted into a DC power supply after a radio frequency interference (RFI) filter, a full-wave rectification and a passive (or active) power factor corrector (PPFC or APFC). Through the DC/AC converter, the high-frequency AC power supply of 20K-100KHZ is output, and is applied to the LC series resonant circuit connected to the lamp to heat the filament, and a resonant high voltage is generated on the capacitor, which is applied to both ends of the lamp tube, but the lamp tube is made" The discharge "turns into" conduction state, and then enters the light-emitting state. At this time, the high-frequency inductor acts to limit the current increase, ensuring that the lamp tube obtains the lamp voltage and the lamp current required for normal operation, and often adds various protection circuits. Such as abnormal protection, surge voltage and current protection, temperature protection and so on. The secret of fluorescent dimming was discovered during the study of frequency. The principle can be easily understood as follows: The new line incorporates a control circuit for the frequency. The higher the frequency, the greater the impedance of the inductive ballast in series with the lamp (XL = 2πFL), the lamp current decreases, the output power of the lamp decreases, and the lamp dims. Otherwise the light is brightened. At the same time, the higher the frequency, the smaller the capacitor impedance, which acts as a stable current. So just like Gree masters the core technology, frequency conversion is also the core technology of fluorescent dimming. Of course, a coin has two sides, the frequency conversion solves the dimming problem, and it also brings EMC interference. The spectrum resources of the space are so limited. Everyone wants to insert one foot, and the three major operators compete for the 4G band. Ballasts are mainly to avoid interference with the infrared. The general home appliance infrared remote control is an infrared signal modulated by 38Khz. Our ballasts generally operate at frequencies between 10kHZ and 100Khz. If the working frequency of the ballast is not well defined, it is estimated that your TV will not be able to open, and the projector will not open when you make a PPT. With the core technology of fluorescent dimming, it is logical to equip it with mature technology in the field of control. 1-10V dimming The mature 1-10V of the 50th generation was quickly grafted to the regulating input used to change the frequency. This is one of the fluorescent lamp ballast dimming techniques we are now familiar with: 1-10V. Of course, the frequency cannot be infinitely high, so the 1-10V dimming cannot make the lamp output 0. The workaround to turn off is to add a relay switch in the control circuit. When the control voltage is lower than 1V, turn off the switch. . This is the general use of 0-10V dimming in North America, with the 0V control switch open to achieve the purpose of turning off the fluorescent lamp. Europeans are more popular with 1-10V dimming. The switch is handed over to others. The control signal of the 1-10V interface is a DC analog quantity, which is continuous, so it is also called analog dimming. The polarity of the signal has positive and negative points. The brightness of the fluorescent lamp is adjusted according to the linear rule. Once the control signal is triggered during dimming, the ballast activates the fluorescent lamp, firstly ignited to full brightness, and then adjusted to the corresponding brightness according to the control quantity requirement. According to the IEC929 standard, the maximum operating current of each ballast is 1 mA. The 1-10V dimming curve is as follows: It is necessary to mention the concepts of Sinking and Sourcing that are often mentioned in control. Use the two pictures inside the digital control to speak: Sourcing is the one that supplies power. The power supply at the input is Sourcing Input / Sinkingoutput, and the power supply at the output is Sourcing Output / Sinking input. Our 1-10V lighting control is commonly used to provide power to the ballast and the controller draws current. Corresponding to Figure 1 on the left above. Typically each ballast provides a current of approximately 0.15-0.2 mA. So how many sets of ballasts a controller can take depends on the current that the controller can sink. If it is 50mA, it corresponds to 200-300 sets of ballasts. Of course, there are so many manufacturers of ballasts to control the manufacturers, as shown in Figure 2 on the right. If the input and output are all of the same nature, you need to add a conversion circuit to match the use. Although the 1-10V control is cheap, there are some restrictions: an additional control line must be added. The group control completely depends on the hardware wiring, and the group change needs to be rewired. If a large indoor space group is fine, the cost on the line is very large. Because it is a voltage analog signal, there will be interference, which will affect the control accuracy. In 1991, Austria's Trido nic developed a digital control interface (DSI) ballast with Manchester Code, including a 1-bit start bit, 8 data bits (dimming value), 4 bits. Stop bit. The signal has no polarity requirement. The signal is transmitted and synchronized on the control line. The dimming is dimmed according to the exponential function. After the ballast is triggered, the brightness of the fluorescent lamp can be adjusted from 0 to the specified by the control signal. brightness. In addition, the DSI can also perform switching control of the 220V main power entering the ballast inside the electronic ballast by signal command. When the fluorescent lamp is turned off and extinguished, the ballast can automatically cut off the 220V main power to save energy consumption. It can also save the main power line connection of the dimmer through the switch control, and directly connect with the 220V main power line, which can also save the system. DSI uses a single-byte light intensity control (0-255 or 000-0FF) to make the control of fluorescent lights easier to connect with digital dimming controllers, thus expanding the range of applications. Tridonic applied for a patent for DSI and became an exclusive agreement. The debate between Google and Apple's open source and closed source has not been concluded, but for lighting, DSI only improves the illumination accuracy compared to 1-10V. The packet routing has not changed, and the human eye is relatively less sensitive to light. So the lighting experience is not a world of difference, DSI can not be as popular as Apple's closed source system IOS, but become lonely. Due to the demand for energy saving, since DSI, Europe has begun to develop and research digital fluorescent lighting control systems. Some major lighting manufacturers have proposed the use of standard communication protocols to accelerate the promotion and use of group-controlled lighting energy-saving products. Major European electronic ballast manufacturers (such as Halvar, Hüco, Philips, Osram, Tridonic, Trilux and Vosslohs2chwabe) have joined the development of the Digital Addressable Lighting Interface (DALI) standard. . At the same time, the Electronic Control Working Group (ECG), (IEC929ΠEN60929) was established, began to draft relevant standards, and formed a draft EU standard. The resulting DALI draft later became part of the EU Electronic Ballast Standard EN60929 Appendix E. The 1-10V analog interface control ballast was also incorporated into the industry standard IEC929 in 1994. In 2001, the World DALI Association was established. Through the launch and application of DALI technology, DALI has become the mainstream standard for digital dimming in Europe. Since the DALI standard is a standard advocated by ballast manufacturers, it is more of an interface standard to facilitate system connectivity. Dimming ballasts are generally divided into communication modules and dimming modules. DALI defines the communication aspect, and the dimming module is also the above variable frequency technology. By replacing the Regulating Input of our previous ballast with our DALI communication module, we got the DALI ballast. For detailed standards on DALI, you can check the relevant standards. I will only list some basic features of DALI applications: 1) Full name Digital Addressable Lighting Interface digital addressable lighting interface, low voltage 0V (-6.5~6.5V), high voltage 16V (9.5V~22.5V), maximum allowable 2V fluctuation; 2) efficient transmission rate (1,200 bits/second); 3) Two-way communication, which can display light source information (such as on/off, true brightness of light source, light source status, etc.); 4) Simple wiring, free wiring, (control signal line has no polarity, no group requirements), control signal line length can reach 300m; 5) A system can allow up to 64 independent address components, and can store up to 16 scenes (16 group addresses). The maximum current of the system is 250mA, and the maximum current of the ballast is 2mA. 6) The dimming range is 0.1%-100%, the minimum limit depends on the supplier, the dimming curve is standardized and adapts to the sensitivity of the human eye (below: logarithmic dimming curve); 7) The lamp can be turned on/off with an electronic ballast (with a certain standby power consumption). The addressing of the DALI ballast is done during system commissioning. Because there are only 0-63 addresses on a DALI line, if only 63 ballasts are produced at the factory, the storage, transportation and use of the ballast are inconvenient. Obviously the ballast manufacturers put the ball. Kicked to the system integrator. The alternative method is to use the random number method to generate the address. Each ballast actually uses a 24-bit storage address (long address), which is uniformly set to FFFFFF at the factory, and the system adjusts the time trial to first generate a random number address for each ballast. (DALI command), the probability of 24 bits generating 2 bits of the same address is extremely small. The DALI ballast on all of the DALI lines is then traversed by sequentially searching for the smallest random number address and assigned to the 0-63 address (short address). The address of any ballast on the control line after each commissioning is uncertain, so when a ballast in the system needs to be replaced, it is not a simple new one, but a new replacement. The address of the ballast must be the same as the address you replaced. You must also re-address the ballast address with a dedicated debug device, otherwise an address conflict will occur. Ok, so far, you have learned three common methods in fluorescent lamp ballast dimming technology, 1-10V analog dimming, DSI digital serial dimming, DALI digital addressable dimming. These three ballast technologies have been developed in fluorescent lamps, but they are not limited to fluorescent lamps, and they have been applied to other fields very quickly. This is a follow-up.
Gang Insulator Isolator Switch isolate swith is an important part of the process of erecting transmission lines. It effectively separates the live conductor from the ground and holds the wire in its own position. The Isolator Switch can operate continuously in the tropics at an altitude of 1000 meters, humidity of up to 90%, Suitable Temperature is minimum of 30℃ to maximum 40℃. (3 Phase Isolator Switch,13 Amp Isolator Switch)
Gang Insulator Isolator Switch Isolator Switch,3 Phase Isolator Switch,13 Amp Isolator Switch,Gang Insulator Isolator Switch FUZHOU SINGREE IMP.& EXP.CO.,LTD. , https://www.cninsulators.com
Figure: Principle of fluorescent light
SCR dimming
Fluorescent dimming (DSI & DALI)
Advantage:
1. Strong aging resistance
2. Long service life
3. Reasonable price
4. Nice Appearance
5. No conductivity dust
6. No insulation object with devastating metal and corrosive gas
7. No violent vibration and striking.
8. No explosive danger and fire
MAIN DIMENSIONS AND STANDARD PARTICULARS
Type
RH-B-11KV-400A
RH-B-33KV-600A
Rated Voltage,KV
11
33
Rated Current,A
400
600
4S Heat Steady e.c.A
12500
12500
Shock Voltage,A
31500
31500
Impulse Withstand Voltage to Earth,KV
75
170
Impulse Withstand Voltage Across the Isolating distance,KV
95
195
Power Frequency Withstand Voltage to Earth,KV
38
70
Power Frequency Withstand Voltage Across the Isolating distance,KV
42
80
We warmly welcome friends both domestic and abroad to visit our company, if you have any questions, please contact with us directly.
The past and present of the development of lighting control
The night gave me black eyes, but I used it to find the light. Human beings are black animals, so humans make light sources and lighting equipment is used to drive away darkness. At night, the earliest human exposure to illumination is lightning and fire. Thunder and lightning cannot be controlled. Humans turn to control and retain fire. Controlling fire to provide light and heat is one of the great achievements of mankind. The first bonfire used by humans was the first source of illumination discovered by the ancestors. It’s dawn, and it’s the most original lighting control. Beeswax appeared around the 3rd century BC, which became the cone of the candle. Later, I experienced the era of animal oil lamps, vegetable oil lamps, and kerosene lamps. Picking up the wick with a needle is the most original dimming control. This way of providing illumination with fire lasted for thousands of years until the emergence of electric lights, a history of thousands of years of technological civilization that ended in the 20th century.
The night gave me black eyes, but I used it to find the light. Human beings are black animals, so humans make light sources and lighting equipment is used to drive away darkness. At night, the earliest human exposure to illumination is lightning and fire. Thunder and lightning cannot be controlled. Humans turn to control and retain fire. Controlling fire to provide light and heat is one of the great achievements of mankind. The first bonfire used by humans was the first source of illumination discovered by the ancestors. It’s dawn, and it’s the most original lighting control. Beeswax appeared around the 3rd century BC, which became the cone of the candle. Later, I experienced the era of animal oil lamps, vegetable oil lamps, and kerosene lamps. Picking up the wick with a needle is the most original dimming control. This way of providing illumination with fire lasted for thousands of years until the emergence of electric lights, a history of thousands of years of technological civilization that ended in the 20th century.
Traditional light source control history
On October 21, 1879, American scientist Edison invented the electric light, the incandescent lamp.
In 1881, the Savoy Theatre in London installed the world's first electric lighting system, using more than 1,150 lights to illuminate the stage and auditorium.
One of the earliest recording dimmers was published in 1890 by Weiwitz's "Safe Dimmers". Prior to this, the dimmer may cause a fire.
In 1903, the Kliegl brothers installed an electric lighting system with 96 resistance dimmers for stage lighting at the Metropolitan Opera in New York City.
Variable resistor dimming is the earliest dimming method. By connecting a high-power variable resistor in the incandescent lighting circuit, adjusting the variable resistor can change the current value flowing through the incandescent lamp, thus changing Light brightness. This dimming method can be used in both the AC and DC power supply loops, and does not cause radio interference. However, due to the high power consumption and large heat generation of the variable resistor, the efficiency of the system is low.
"The incandescent lamp is heated by electric current, which converts thermal energy into light energy. This form of utilization of electric energy is too wasteful. Can it open up a new way of utilizing electric energy?"
In 1902, Hewitt invented a mercury lamp, also known as a mercury lamp. This mercury lamp is filled with mercury and a small amount of argon in a vacuum tube. After being energized, the mercury evaporates and is excited by the electrons to emit light. Mercury lamps are much brighter than incandescent lamps, and the light is similar to sunlight, and the energy utilization rate is also high. However, mercury lamps emit a large amount of ultraviolet light, which is harmful to the human body; and the mercury light line is too bright and too glaring, so it cannot be widely used.
In 1910, France's A. Claude invented a xenon discharge lamp. He filled the lamp into a lamp to make a blue-emitting lamp, and later applied phosphor on the inner wall of the tube to make a white-light tube.
In 1938, Iman, a researcher at General Electric Company of the United States, like other scientists, saw the bright future from the bright light of neon lights and developed a hot cathode fluorescent discharge lamp.
In 1942, a calcium halophosphate fluorescent lamp was successfully developed.
Fluorescent lamps after the 1950s mostly use calcium halophosphate, commonly known as halogen powder. The halogen powder is cheap, but the luminous efficiency is not high enough, the thermal stability is poor, the light decay is large, and the luminous flux maintenance rate is low. Therefore, it is not suitable for a compact fluorescent tube with a small diameter.
Also during this time, the foundation of modern control: the introduction of thyristor technology. China is still undergoing a vigorous Great Leap Forward during this time.
In 1956, the Bell Lab invented the thyristor and controlled the silicon. In 1957, the United States General Electric Company (GE) developed the first thyristor product; in 1958 it commercialized it; opened up power electronics. A new era of rapid technological development and widespread application.
Just two years later, Mr. Joel Spira invented the world's first twisted electronic dimmer in 1960, which has changed the development of the entire lighting control industry.
Mr. Spira founded Lutron Electronics in the United States in 1961 and introduced its invention to the market. Since electronic dimmers are as large as wall switches and save power, they are so popular that they quickly replace old dimmers. The home can install such a power-saving and slim dimmer on the wall, and the appearance of the home lighting changes accordingly. Today, such knob-type electronic dimmers are still visible in some homes.
Traditional light source control history
In 1959, it was discovered that the tungsten halogen cycle can greatly slow the evaporation of tungsten. Further, a halogen lamp was invented. Improves luminous efficiency and extends lamp life.
Figure: Principle of tungsten halogen cycle
In 1961, high pressure sodium lamps appeared.
Figure: Typical spectrum of sodium lamps
In 1962, metal halide lamps were introduced.
Figure: In the early 1960s, metal halide lamps came out
In the 1970s, with the invention of large-scale and very large-scale integrated circuits, fourth-generation digital computers were widely used, resulting in a "centralized control" central control computer system. This central centralized control system is also used for lighting control.
In 1971, the representative manufacturer of Crestron was established. Later developed into a famous manufacturer of home control. Of course, lighting control has also become an important part of the control.
A worldwide energy crisis emerged in the 1970s (the fourth Middle East war broke out in October 1973, in order to crack down on Israel and its supporters, the Arab member states of the Organization of Petroleum Exporting Countries announced in December that they would withdraw oil pricing rights and The price of crude oil increased from $3.011 to $10.651 per barrel, causing oil prices to more than triple, triggering the worst global economic crisis since the Second World War. Many companies are committed to new energy-saving electric light sources and fluorescent lamps. Research using Electronic Ballast for Fluorescent Lamps.
In 1974, Jverstegen JM of Philips, the Netherlands, synthesized rare earth green powder (Ce, Tb) MgAl11O19, blue powder (Ba, Mg, Eu) 3Al16O27 and red powder Y2O3: Eu3+. They were mixed in a certain ratio to prepare a tribasic toner. Its luminous efficiency is high (average 80lm/w or more, color temperature 2500K-6500K, color rendering index 85 or so).
Figure: Three primary color spectrum
With the rapid development of semiconductor technology, various high-reverse power switching devices have emerged, providing a prerequisite for the development of electronic ballasts.
In the late 1970s, companies such as Philips in the Netherlands took the lead in launching the first generation of electronic ballasts, a major innovation in the history of lighting appliances. Because of its many advantages such as high efficiency and energy saving, it has attracted great attention and interest from all over the world. It is considered to be an ideal product to replace the magnetic ballast. Some world-famous companies have invested considerable human and material resources to conduct higher-level research and development.
In the early 1980s, Philips developed the BHF132H12 (single tube 32W) and BHF232H12 (double tube 32W) fluorescent electronic ballasts. It uses 120 discrete components and is the most complete representative product. Due to the rapid development of microelectronics technology, electronic ballasts have been promoted to high performance and high reliability. Many famous semiconductor companies in the world are scrambling to introduce dedicated power switching devices and control integrated circuit (IC) products.
In 1984, Siemens developed an active power factor effector (APFC) IC such as TDA4812 with a power factor of 0.99 or higher. Companies such as Thorne in the United States, GE in the United States, and Osram in Germany have successively introduced integrated electronic ballasts.
In the late 1980s, technologies such as computers, communications, microelectronics, and automation were rapidly developing, and the field of control was developed to fieldbus technology. It fundamentally breaks through the limitations of traditional "point-to-point" analog signals or digital-to-analog signal control, and constitutes a fully distributed, fully digital, intelligent, bidirectional, interconnected, multivariable, multi-contact communication and control system. .
During this period, Australia Dynalite was established in 1989, and its Dynet bus system is a fieldbus system dedicated to the specific practice of lighting.
Dynet is a closed fieldbus, and KNX, EIB, etc., which we are familiar with, are open buses. All of these fieldbus-based lighting control systems are skipped. Because bus technology is ahead of many mainstream lighting source dimming control technology, many of our lighting interfaces have not yet been born. Therefore, Dynalite's early control of lighting was limited to the lighting switch and the phase-cut dimming of incandescent halogen lamps. Fortunately, this situation did not last long.
In 1989, the Hilvali company in Finland successfully launched a dimmable monolithic integrated circuit electronic ballast. Fluorescent lamps, the dimming of the dominant light source in this market has finally become possible.
Leading edge phase dimmer
They are generally very simple to wire, as long as the dimming panel is connected in series to the fire line of the lamp (some are also connected to the zero line), turn the knob to see the bulb can adjust the brightness.
So how does the thyristor achieve chopping?
The leading edge phase-cut dimmer circuit is relatively simple, generally including a DIAC (bidirectional trigger diode), a TRIAC (thyristor, hence the name thyristor dimmer).
As shown in the figure, the front parts L1 and C1 are RF suppression circuits, and VR1, R1, C2, and C3 form an RC circuit. When the RC charging voltage is greater than the DB1 (DIAC) conduction voltage, DB1 is turned on, triggering TR1 (TRIAC) conduction. Pass, at this time 220V voltage is applied to the bulb, when the current crosses zero, TR1 is turned off. Repeat this way. The time constant RC can be changed by changing the size of the VR1 potentiometer, thereby changing the conduction angle. That is the width of our chopping.
Therefore, the characteristics of the front-end phase-cut dimming are combined: in each half cycle, the zero-crossing is turned off, and the delay is turned on to the end of the half cycle.
The corresponding voltage waveform is as follows:
This type of dimmer has an absolute dominant position in the market because of its simple line and low price.
Of course, this type of dimmer has limitations: it is only suitable for resistive and inductive loads, not for capacitive loads (voltage abrupt, producing very large inrush currents). Reduce line power factor and EMI interference. The thyristor works well above the holding current and is therefore not suitable for deep dimming.
Trailing edge phase dimmer
The thyristor dimmer has a very steep leading edge when it is turned on, and the voltage waveform suddenly jumps from zero voltage, which has little effect on the incandescent lamp-like resistive load, but is not suitable for dimming of the gas discharge source.
Because most gas discharge sources require a drive circuit to work together, and the drive circuit is a capacitive load, the voltage jump generated by the thyristor dimmer can generate a large inrush current on the capacitive load, making the circuit The work is unstable and even causes the drive circuit to burn out. Therefore, a trailing edge phase dimmer was later appeared.
Here is also a brief introduction:
The trailing edge phase-cut dimmer generally includes a zero-crossing detection circuit, a timer, and a MOSEFT switch.
Also, as shown, L1 and C1 act as RF inhibitors. There is a zero-crossing detection and timer in the circuit. When the zero-crossing detects zero-crossing, the timer is reset, and the timer outputs a high voltage. The MOSFET is turned on, the circuit is turned on, and the timer starts to count. After the set time (ms, less than After half cycle, the timer outputs a low level and the MOSFET turns off. The voltage output is interrupted.
The corresponding voltage waveform is as follows:
We can see that the circuit of the trailing edge phase dimmer is much more complicated than the front edge phase cut, and the price is much higher than that of the front edge phase dimmer, so in the incandescent era, the leading edge dimmer (thyristor Optoelectronics) monopolizes most markets. When the advantage of then phase-cutting is that it is suitable for capacitive loads, the voltage rises slowly and does not cause extreme surges.
Some manufacturers also produce universal dimmers (ie for resistive, inductive, capacitive loads), the principle is to actively identify the type of load, automatically select the front cut or the back cut.
Also during this time (1950s), the field of process control was also in full swing. A simulation process control system based on a current analog signal of 0-10V or 4-20 mA is widely used. After the birth of the thyristor, 0-10V was also used for lighting simulation control.
So we can now see some old 1-10V systems with incandescent and halogen 1-10V dimming controllers, but using 1-10V to convert to thyristor dimming is a bit of a superfluous feeling, so based on incandescence The 1-10V controller of the lamp is dead.
Dimming of fluorescent lamps (1-10V)