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 Breaker utilization in various fields of factory! High voltage and low voltage are inseparable from the circuit breaker, it is a very basic low-voltage electrical, circuit breakers with overload, short circuit and under voltage protection function, the ability to protect the circuit and power supply.

Mold testing, mechanical testing, Motorcycle detect sophisticated detection, regular contact detection applications, some detection application, but we rarely come into contact with, however, only in the application of professional products, we can see. For precision measuring instruments in these areas, we know knowledge is little lithium batteries chip detection is one of them.

Lithium batteries chip detection applications for the sophisticated detection equipment, a lot of people do not know, even the the battery supplier personnel do not know, only the most professional fishes lithium batteries chip detection understand about the lithium battery knowledge of chip detection.

Lithium batteries chip detection applications, do not understand the reason why, is because it simply does not believe the application of precision measuring instruments secondary image measuring instrument and coordinate measuring machine in it. Really know the quadratic elements and three-dimensional applications, will naturally think lithium batteries chip detection is also very simple.

Detection of lithium batteries chip, from the concept, and we know mold detection gear detection as through 2D image measuring instrument and the application of the three-dimensional measuring machine, workpiece data parameters detected products production safety protection. Say they are different, then they detect the instrument used was different.

Detect mold detection gear, the main application of the detection instrument coordinate measuring instrument, lithium batteries chip detection based on the use of 2D image measuring instrument detection-based. In lithium battery microarray, mainly in order to get the two-dimensional coefficient of the chip, so use quadratic elements video measuring instrument can solve the problem. Sometimes need to detect 3D chip data, using the 2.5-dimensional measurement tasks can also be completed.

The reason why the introduction of lithium batteries chip detection, not for its detection principle, but let everyone know 2D image measuring instrument widely used, so our measurements has a lot of help on the use of 2D image analyzer.

This article will focus on the patte of Fujian, Jiangxi and other southe regions of the chip industry to do depth profiling.

Number of enterprises accounted for 24%
Fujian has been put into production LED epitaxial silicon vendors a total of three, Xiamen Sanan dry according to Xiamen and Xiamen Jingyu, in the construction of the project 5.

Xiamen Sanan Optoelectronics already have three production base in Xiamen, Tianjin and Wuhu, become the delay chip leading enterprises at home and abroad; Xiamen dry according to the main red, yellow, light LED chip suppliers, currently has two production bases in Xiamen and Yangzhou ; Xiamen Jingyu Taiwan Epistar chip processing base in the mainland, only chip back-end process processing, does not involve the epitaxial growth.

The LED epitaxial chip companies Jiangxi has been put into the crystal can, Jiangxi Nanchang Yan Lei. Jiangxi crystal energy is only a part of growing epitaxial silicon substrate manufacturers, with a production base in Changzhou; Nanchang Yan Lei is a domestic Established earlier one LED chip manufacturers currently engaged chip backend process processing .

Other southe epitaxial chip companies are mainly located in Anhui, Hunan and Hubei. A small number of enterprises, the least number of firms in the region for the five regions.

Anhui enterprises already in operation for four, Wuhu Sanan Optoelectronics, of Wuhu, BDO Runda, Hefei rainbow Blu-ray and Ma On Shan photoelectric harmony. Previously, Wuhu Sanan Optoelectronics planning the introduction of 200 sets of MOCVD Wuhu BDO Runda planning the introduction of the 100 sets of MOCVD So far, the two companies put in place the machine count was over 50%, and most machines have been realized and put into production. Hefei rainbow Blu-ray project planning the introduction of the 200 sets of MOCVD so far has been the introduction of dozens. Overall, Anhui Province, China currently has the largest number of MOCVD installation provinces.

Hunan has been put into the business is just a - Xiangneng Hualei. Xiang Hua Lei strong financial background as a state-owned holding company, currently has 32 MOCVD, most of which has been mass production.

The Hubei enterprises already in operation for the three, Wuhan Can, Wuhan Di source, Wuhan Yuanmao photoelectric. Wuhan Can domestic LED display chip manufacturers, Wuhan Di source is one of the few domestic focus on high power LED manufacturers, Wuhan Yuanmao photoelectric Taiwan Ding Yuan production base in mainland China.

Overall, Fujian, Jiangxi and other southe small number of firms, but larger than the scale of production and marketing.

The MOCVD install accounting for 43%
Fujian, Jiangxi MOCVD installed slightly higher than the number of other southe enterprises of the Pearl River Delta region although it is at least five regions, but capacity is the biggest. The data show that, The other southe MOCVD installed accounting for 36%, 2 percentage points higher than the Yangtze River Delta region, mainly due to number of MOCVD install in Anhui Province in the past two years, the rapid increase.

Fujian, Jiangxi, currently owns MOCVD enterprise Xiamen Sanan, Xiamen dry according to, and Jiangxi crystal can. There are also some have introduced a MOCVD but not yet put into the enterprise, such as Xiamen developed crystal. Prior to the above-mentioned regions enterprises the majority of the expansion plan arrangements in other regions, the future of the region chip output value accounted for will be gradually reduced.

Anhui domestic MOCVD installed the largest number of provinces, the MOCVD install more than 200, Sanan Optoelectronics has 107 Taiwan, the BDO Runda has 50 units; the Hubei's Hua Canguang electric and Di source photoelectric MOCVD installed a total of more than 40 units; the Hunan Hua Leiguang electrical MOCVD installed more than 30 units. Other southe LED chip capacity is the largest area, is expected to also the future capacity of the largest regional.

Output value accounting for about 38%
2011 in Fujian, Jiangxi LED chip output value accounted for 14% of the total output value of domestic chip, ranked fourth in the five regions, including Xiamen Sanan, Xiamen dry according to, and Jiangxi crystal can is a major contributor to the output value.

Because the other southe LED chip production capacity has yet to truly release in 2011, the region chip output value accounted for after the Yangtze River Delta region ranked second with 24%. Since the beginning of this year, Wuhu Sanan, Wuhu BDO Runda, of Hefei rainbow Blu-ray and Hua Leiguang electricity production capacity utilization increased gradually the, GLII expects LED chip output value of the region in 2012 will exceed the Yangtze River Delta region ranked first of the five regions.

Future development
As of June 2012, Fujian, epitaxial chip companies have not yet been put into operation in Jiangxi province seven, five already in operation, the total planned MOCVD number of 357 units, more than 50. Southe region has not yet been put into operation three enterprises, enterprises have been put into operation eight the future planned MOCVD number of 815 units, more than 200 units.

Point of view, the future of the northe region and the Yangtze River Delta region total planned MOCVD number of installations is much larger than in other regions, but considering that in 2011 more than 400 new MOCVD, existing capacity has been a serious surplus in the coming years from the planning figures , the number of new MOCVD will be drastically reduced, and a lot of planning will be difficult to come to fruition.
MOCVD number of other southe regions have the first of five regional point of view from the existing production capacity from the existing production MOCVD quantity point of view, to Sanan Wuhu, Wuhu BDO Runda, Hua Leiguang electricity as representatives of other the south epitaxial chip companies in the leading position.

Beginning in 2012, regardless of capacity or yield other southe regions in the future for a long period of time will be in the leading position in the country, three safety optoelectronics,, BDO Runda and other representative enterprises will become a major force in GLII expected.

Similar the ordinary infrared LED shape and visible LED, but it emits infrared light. Its pipe pressure generally drop to about 1.4v, generally less than 20mA operating current. In order to adapt to different operating voltages, the circuit often string current limiting resistor.

For a table lamp, energy-saving, environmental protection, multi-function is the key to an attractive. Have you ever thought about with a lamp to frame and give i the iPhone charging it? Satechi recently released smartphone powered light can borrow Satechi Smart LED desk Lamp smart table lamp. The overall volume of 7.1 x 17.6 x 32.6-inch, weighs just 1.9kg. Smart table lamp design simple and foldable, and has a variety of lighting features. Lamp with several flexible axis, the angle can be freely adjusted, suitable for any office space or spaces. 1 hour timer built-in one-touch control and intelligent auto-off feature, the use of low-power energy-saving convenience allows you to easily use.




Satechi, Smart LED Table Lamp intelligent LED table lamp at the bottom of the back USB interface, compatible iPhone5, iPad, or laptop computers and other digital devices. There are two colors, including black and white. Pricing is $ 99.99 each, equivalent to about 623 yuan. Although it is a very practical accessories suitable for office workers and students, it is a pity that the price is too high.

Xiaobian think, the highlights of this lamp only that can be timed to tu off the lights and low-power energy-saving, for charging iPhone, it is still a little tasteless, after all, since it can be affirmed this lamp also need outlet Since there is a plug-in, why can not direct the phone plugged into the outlet, rather than use the desk lamp to charge it?

What They Are:
When electric accepted is anesthetized beyond the alliance of two antithetical crystals ablaze and calefaction is accustomed off. This is the base of Ablaze Emitting Diodes (LED).
However if too abundant calefaction is created the crystals will breach down and in convenance this agency that the ability of an LED ablaze is bound and that they will accomplish abundantly alone beneath an ambient temperature of about 40 degrees C.

Power of LED Lights accessible end 2011
As the accepted is added added ablaze and calefaction is generated but the accepted technology cannot blow absolute calefaction and this banned the ability of LED chips.
For backup bulbs such as an MR16 the best ability is 6 or 7 watts unless automated cooling such as a fan is used.

To get added power, a ablaze applicable can be advised to use assorted LED's or with added busy calefaction sinks that are able to accumulate the LED chips cool. Our a lot of able downlight is 25 watts.

Life of an LED
There are alone a few companies authoritative LED chips such as Cree, Osram, Phillips, etc and a lot of LED ablaze accessories and bulbs use chips from these manufacturers.
The dent manufacturers apprehend up to 100,000 hours activity but this is bargain badly by the accepted activated to the chip.

350 milliAmps will accord maybe 50,000 hours but college wattage units may be applying 900 milliAmps and the activity will be bargain to 20,000 hours. This is the abstract time for the ablaze achievement to adulteration to an unacceptable level, but unless the dent is damaged it will abide to afford light.

Brightness
This is breadth the LED adventure becomes confusing. The bulk of ablaze accustomed off at a antecedent is abstinent in Lumens, but the bulk of ablaze hitting a apparent is depends on the ambit amid the ablaze antecedent and the apparent and is abstinent in Lux.

The LED chip currently acclimated can catechumen 1 watt into about 80 Lumen. Quite generally the ability absent in the disciplinarian is added to the lamp's appraisement so not all the watts traveling into the lamp are getting adapted to light. ie a "6 watt" lamp may alone accept 5 watts in fact extensive the crystal. This is not consistently accepted so a added reliable admeasurement of the accuracy of the lamp is the lumens claimed.
For archetype MR16 halogen backup lamps accord off amid 200 and 450 lumen. For allegory a 50 watt halogen lamp gives off 950 lumen. So about you amalgamation it a change anatomy 50 watt halogen to 6 watt LED bulbs will not accord the aforementioned bulk of ablaze in a room
However if the ablaze achievement is focused into a attenuated axle again the LED lamp can aftermath an breadth with aforementioned Lux as a halogen, so the claims that a 3 watt LED is according to a 50 watt halogen are array of accurate if you alone wish a one beat atom of light.

Use of LED's.
These are acutely advantageous in bartering applications breadth the top basic amount is account by alienated the amount of alteration lamps and top hours acceptance gives accomplished ability savings. The aftereffect time can be analytic short.

For the home LED's are accomplished for use in ambient lighting and garden lighting. They are ideal for amount wells, corridors, and to accommodate affection lighting in lounges and TV areas. The acknowledgment is that the ablaze above is above to halogen lamps Using LED bulbs in accepted garden accessories can abate the ability acclimated dramatically. A garden can be lit with beneath than 100 watts, so the garden or drive lights can be larboard on every night with the ability use of one old appearance bulb. 5 watt LED bulbs can be adapted anon into absolute accessories as the 12 volt wire anguish transformers will accumulation the actual voltage. Alone 5 watt is recommended as added ability will overheat the bulbs in the absolute accessories and could cause them to fail.

To benefit from the demand for large-size TV and direct type LED-backlit LCD TV Product warming, LED chip price decline this year less than in previous years, the reduction from 20%, Epistar, Formosa Epitaxy LED chip plant operating pressure slightly slowed.

Epistar general manager Zhou Ming Jun, backlight chip products offer fall further limited space, although the first quarter is traditionally the low season, entering the season with the second quarter in succession, however, demand is expected to rebound, prices should also have some supporting role.

Zhou Ming Chun pointed out that South Korean companies Attacking LED lighting action is positive, and the South Korean companies also often take the lead in price competition, so the decline in value of the pressure of the lighting chip but rather greater than the backlight chip.

Insiders pointed out that, although Taiwan LED chip factory competitive force is still leading Korea, but competition in the packaging factory, the South Korean companies leading in Taiwan, including Seoul Semiconductor (SeoulSemiconductor) and LG (LG) under the LGIT, even also take the lead in bargain .
South Korean companies recently Attacking Japan LED lamp market at a low price strategy, it also raised the Japanese manufacturers rushed to find Taiwanese manufacturers fight against South Korea to form another form associated the table Kanghan phenomenon. In addition, a research organization pointed out that, the Korean brand late last year also the United States and Europe and the United States push low-cost LED bulbs products, and almost the lowest in the market.

However, the next another may affect the quotation trend variable is LED manufacturers in mainland production carve out the situation. Packaging factory, LED chips prices, or signs of decline, especially in the low-power and medium-power part, because this is the the mainland manufacturers market competition, and therefore decline in value often than the high power products to the more obvious.

With the advent of high-power LED, general fluorescent or incandescent 5 to 7 times its luminous efficiency, energy-saving effect is very significant. Thus, the high-power LED has broad application prospects. Currently, a single high-power LED has 1W, 3W, 5W and 10W, has been heavily used 1W and 3W high power LEDs, multiple high-power LED series and parallel, the the combination output power reached 70W ~~ 100W.

High-power LED with high luminous efficiency and energy-saving advantages, but inconsistent pipe pressure drop is the need to overcome the shortcomings. Second, poor temperature characteristics of the high-power LED. Tube current and luminous efficiency varies greatly with the junction temperature and ambient temperature changes, which bring inconvenience to use.

High power LED above shortcomings, people use more than two drive options: 1. Constant voltage source driver. That is, using a plurality of LED in parallel with a constant voltage source driver. Thus, since the tube voltage drop of the LED is inconsistent, so that the diode current is inconsistent, so that the luminous efficiency is also quite different. This program is seldom used in high-power LED. 2 constant current source driver. Inconsistent pipe pressure drop of the high-power LED, LED by their junction temperature and ambient temperature influence, so the number of LED series and driven with a constant current source can effectively overcome these shortcomings.

The main features of the high-power LED

Operating wavelength
The operating wavelength of the high-power LED with its glowing colors. For example, cold white LED operating wavelength of 525 angstroms to 600 angstroms, while warm white LED operating wavelength between 525 angstroms to 675 angstroms.

Forward voltage drop
High power LED's forward voltage for each change of 0.1V, the current change of about 100mA.

The relationship of the working current and luminous intensity
The high power LED luminous intensity of its junction temperature and ambient temperature. This is mainly due to temperature increases, the operating current is also reduced correspondingly, Similarly, LED's luminous intensity and its current relationship is approximately linear, and its working current each reduction 100mA for 1W and 3W LED, the light emitting intensity is reduced about 15%.

High power LED series constant current

The principle of the source drive
Currently appearing on the market of high power LED series drive has its limitations, typically three to six LEDs in series, and the number to be sure, can not be any connection. In this paper, an arbitrary (1 to 20) LED constant current source driver program series, shown in Figure 1, the following works:

1W LED, for example, the rated current of 350mA. For some reason, the LED current is reduced, the constant current source circuit of the acquisition to the current value of the change (decrease) after having amplified by U1 transmission to the control circuit. Inversion processing in the control circuit of the sampling signal, the output pulse width is increased. Power tube D5 conversion stage of the driving power of the output pulse width increases, so that the secondary output voltage increases. In this way, the voltage across the LED in series also increases, therefore, the current flowing through the LED is also increased, which maintain a constant LED current. Similarly, if for some reason, so that the LED current is increased, contrary to the control process. Advantages that: The constant current source drives regardless of the LED voltage drop difference Junction ambient temperature changes cause changes in diode current much, can be accessed through the rapid adjustment of the high-speed constant-current source circuit to Maintain constant current LED.

High power LED constant current source
To pay attention to the design of the drive

The design of high-power LED constant current source drives should pay attention to the following points:
1. To select the control of the control chip of the circuit in accordance with the number of the LED series. Because of the number of LED chips required output power is different. Figure 1 ICE 2A165, also choose other similar switching power supply control chip.

2. Switching power supply transformer leakage induction is as small as possible, otherwise the drive will reduce the reliability. Because the leakage inductance of the transformer, switch off instantly produces very high reverse voltage spikes, severe cases may exceed the breakdown voltage of the control switch, leaving the LED chip breakdown, causing the reliability of the drive is greatly reduced. Switching power supply transformer T1 is the key parts of the product, it is necessary to the production of the professional manufacturers.

3. The operating speed of the constant-current source circuit to be fast, so that can make the LED safer. In this paper, series of LED drive any number (1 to 20) of the series, this would require the change of the output voltage of the switching power supply faster to adjust slowly, and may cause damage to the LED's.
Practice has proved that this paper, high-power LED constant current source drives the program is feasible, and compared with other drives, lower cost, which has broad application prospects.

Zhejiang Intel Optoelectronics Technology Co., Ltd. in the Changfeng Garden Hotel held a grand press conference grand release SMD3535 light source new products. Shanghai Sansi Electronic Engineering Co., Ltd., Shenzhen City the Xiang Hui Keguang electric Science and Technology Co., Ltd., Shenzhen, as Kaiwei Optoelectronics Co., Ltd., Shenzhen Ralink Technology Co., Ltd., Shenzhen the Corrente Science and Technology Co., Ltd., Shenzhen Lan Pu Technology Co., Ltd and other well-known brand manufacturers are invited to participate in the event.

Intel to photovoltaic research and development center director, Mr. Li Gesheng introduced to the guests the LED display market trends, and Intel to SMD3535 characteristics lnteled SMD3535 new “cook” Italy and lnteled of SMD3535 overall solution done a detailed explanation .

The face of growing demand of the market for high-definition display status of traditional plug-in oval LED clearly does not meet customer needs. Outdoor full color SMD LED has wide viewing angle, light distribution and light mixing good, high contrast and easily automated production advantage, becoming the next screen mainstream light emitting devices. As a professional LED packaging manufacturers, lnteled Optoelectronic this release SMD3535 products lnteled latest first outdoor LED HD display special products production has a domestic first episode. The product has two the lnteled patented moisture-proof, moisture level; possess super anti-UV, anti-sulfide capacity, long used outdoors; with a high-definition, high-resolution, very suitable outdoor high density screen; and brightness Up to 1600mcd.

For the SMD lamp beads used for outdoor display, the industry has been the existence of two doubts: only heightening the height of the lamp body will be able to crack the SMD moisture-proof problem? The SMD moisture resistant plug-in LED can transcend it? To this end, lnteled Optoelectronic released SMD lamp beads for outdoor display humidity the Thermal Shock destructive experimental standard, to test SMD lamp beads suitable for outdoor display. (SMD lamp beads First on the -40 ° C cold red box cold red 30 minutes, and then immediately placed into a 100 ° C boiling water and cook for 30 minutes, remove and lit test and record to do 100 times this reincaation. ) after the experiment, we leaed that no one lights died the 100 lnteled SMD3535 after 100 full humidity of hot and cold shock destructive testing, the dead lights rate of 0, a well-known foreign brands SMD3535 rate of 2 dead lights %, SMD5050 dead lights rate of 83%, the 546 dead average lamp was 40%; 100% rate of a well-known domestic brands SMD3535 dead lights, its the SMD5050 dead lights rate of 34%. So bad under the experimental conditions, lnteled SMD3535 dead lights, what the environment can not adapt to it! Lnteled SMD3535 outdoor high-definition display partners!

In today’s competitive market, as a professional LED packaging manufacturers in order to help clients improve their competitiveness, Intel , need to understand customer needs, close to good customer service, so that a SMD3535 the play to the best performance, and provide customers with one-stop solutions, enabling customers to do “to that war, the war will be won. On this basis, Ge Li Sheng, director for the optical, thermal, SMD3535 highest use of the relationship between temperature and the brightness of the screen, the SMD3528 the largest screen brightness LED dot pitch, LED display cabinet design several ways to do a comprehensive and detailed analysis. Cabinet design (PCB drawings, schematic drawings, structural drawings, BOM list of module test report can refer to physical PH10 sample box, reference suite PH10 3535 suite), free for partners available.

The switching regulated power supply volume is small, light weight, high efficiency, the Regulator a wide range of safe and reliable, to be used in many electronic devices. However, like other circuits also exist some problems, such as the control circuit complexity, higher operating frequency be TV, radio, electromagnetic radiation interference to radio noise appears, TV noise points, even feedback interfere with other electronic devices work properly.

1 super audio interference oscillation problems

The operating frequency switching regulated power supply is more than for 20-100kHz, is a super audio range. To a frequency corresponding to work as a switching regulator of the power supply device transistor or field effect transistor in the conduction and cutoff state, the oscillatory waveform approximates a square wave (overshoot), and can be decomposed according to the Fourier analysis method, i.e. to obtain the DC component, the fundamental and higher harmonics of the fundamental energy, followed by three, five, seven ...... and so on.

Radio and electromagnetic interference

As we all know, radio modulation method to disseminate information. The audio signal in the high frequency load uses amplitude modulation (AM) and frequency modulation (FM) method, and then modulated wave through the transmission antenna will be radiated out in the form of electromagnetic Phi radio receiving device via the receiving antenna receiver down s and then The frequency selection, frequency conversion, amplification, and demodulation, restore an audio signal, and finally through the low-frequency amplifier, the sound emitted by the loudspeaker. If only a modulation signal of the high frequency carrier without audio range, then its energy is again large, the radio receiving apparatus is also not be restored through a speaker any audio information. It can be thought, just super audio side Phi the presence of interference (the lower limit frequency of the audio oscillator 15k! Carpet, already outside of the audible range of the human ear), generating a higher harmonic does not become through Xin, the radio interference signal to the audio range, fact such interference sometimes very serious, may in the medium wave, short wave range are strongly noise, then the interference from where? there is audio switching regulated power supply scope of the interference signal, and modulation of each harmonic oscillation super audio, similar to the way radio interference with radios and other equipment, is an important source of interference.

3. Direct rectifier capacitor filter circuit characteristics

Directly to AC power rectifier filter high-frequency switching power supply, AC input voltage of 220V, 50Hz, generally use a bridge rectifier circuit, and then becomes 100Hz jagged pulsating DC voltage electrolytic capacitor filter, to the switching regulated power supply.

Can be seen from the figure, the role of the AC power supply is the energy of each Wms to the electrolytic capacitor charge time, to complement consumption by the switching circuit, a sawtooth-shaped voltage waveform from the point of view, but is pulsed current waveform from the point of view shaped, they are non-sinusoidal periodic volume contains rich harmonics, and the vast majority in the audio range (20-20000Hz) which l00Hz composition is likely to produce an important source of audio interference.

Similarly, according to the Fourier analysis, the non-sinusoidal periodic function can be decomposed into the fundamental wave and higher harmonics, its energy is concentrated in the vicinity of the fundamental and higher harmonics little energy. Because of its peak-to-peak value is small (only a few volts to a few card volts), if in the form of electromagnetic waves emitted by certain circuit elements (such as the LC network, etc.), the interference on the radio, etc. Element radio receiving apparatus is small. The the 1000kHz frequency in the medium wave band (531-1611kHz), for example, 1 ∞ Hz pulse-shaped current of 1 kHz harmonic before whom resonant frequency energy is almost zero, unless the radio is close to the place it , it is impossible for interference. But in fact many of the radio in the far distance of the switching regulator power position can still appear interference, because what is it? Can conclude the following analysis.

A low frequency signal to modulate the amplitude of the high frequency carrier so that a high-frequency carrier the same as the overall envelope and the variation of the low-frequency signal, which is an AM the corresponding modulated wave is amplitude modulated wave. If the low frequency signal is a single frequency sine wave, the high frequency carrier is a single frequency sine wave, both obtained by modulating role amplitude modulated wave, according to the principle of amplitude modulation, the amplitude of the amplitude of the low frequency signal with the high frequency carrier signal is less than 1: 3 cases, the carrier envelope is substantially similar to the low-frequency signal. If the low frequency signal is a plurality of frequencies, the amplitude modulation wave spectrum is the carrier and the two upper and lower sidebands. The switching regulator power supply of the low-frequency pulse amplitude is smaller the larger the amplitude of the high frequency of the switching pulses in the switching regulator power supply inteal AM role is bound to occur, and therefore the electromagnetic radiation generated by the power supply is amplitude modulated interference wave, since Both contain a wealth of fundamental and harmonic. The result of cross-modulation makes interference throughout the the super audio over a wide frequency range, Xin strong interference sound in the medium and short wave range, and this interference almost throughout the entire band.

To further verify the presence of the aforementioned problems, instead of AC power directly to the switching power supply with a DC power supply, test results, as anticipated, as that since there is no 100Hz charging pulse, tu the radio on which are Xin less than the noise emitted by the radio.

According to the above test can get the following conclusion: switching power supply for the yuan radio broadcast interference from 100Hz low frequency charging pulse harmonic modulation high frequency square wave form complex amplitude modulation wave. As the intensity of high-frequency switching square wave, not easily suppressed, it should not be reimbursing to strengthen the capacity of the high-frequency filter capacitor.

Thus think of the Electronic Ballast pollution problem of the electromagnetic environment, Electronic Ballast also do the test, fluorescent lamp can be lit, but the attendant problems in the fluorescent light is almost impossible to use The Radio received Xin broadcast, the radio signal is drowned in the noise, but also due to the load of the electronic ballast is exposed to the space and the size large fluorescent interference by its radiation intensity of electromagnetic waves, the noise is very serious.

Anti-jamming measures

In summary, the switching regulator power electromagnetic radiation interference from the low-frequency the 100Hz charge pulse and its harmonics amplitude modulation, super audio oscillator square wave and its harmonics weakened mainly by the following:

(1) using the appropriate filtering capacity electrolytic capacitor. Mainly from two aspects of anti-interference and cost performance should be considered.
(2) In the case of the possible, using appropriate methods to reduce overshoot and ringing super audio oscillation square waveform. The purpose of doing so is to reduce the super audio oscillation high harmonic energy, which can reduce the level of radio interference.
(3) the perfect calendar filter network, weaken the interference of switching regulated power supply to the AC mains reinfusion. The filter network in the form of a lot, according to the specific power supply manufacturer and the load to comprehensively consider the selection circuit forms.
(4) reasonable design of printed circuit board, a large area of ​​ground measures, while strengthening the shield. This can effectively reduce the intensity of electromagnetic radiation caused by the distributed capacitance, and is also able to improve the reliability of the power supply.