how to test the T-350

  • Step1

Try this device by another power socket in another room.

  • Step 2 :Please donot connect this line. To see if it still goes off or not?If it doesnot go off, then please test the steps as follows; if it still goes off , then it is not the problem of the power supply itself. (You may find the problem by yourself. In other means, our device is ok.)


After the step 2 , the power doesnot go off, then do the test as follows. Step 3: To test the input (L , N , pole) does or doesnot leakage to the shell. If not, it device is ok.

(From the right to left, the third screw is connected to the shell

  • Step 4: To test the output part does or doesnot leakage to the shell. And if it doesnot, then the device is ok.
  • if step 2,3,4,5 is ok, to do the Step 6, then open the shell.

Step 7: Test this part is connected to the shell or not? If it is connected to the shell,



(When you can test the resistance is small,)  then please take this part(blue insulating strip) out of the power supply to see if it is broken.) and if not, it is ok.


  • Step 9:

It is important, to open the shell, to see if this part (the switching point, or the black part) is on the left side of the power supply or not, if it is on the left, then it is ok. If not, please make it to the left of the device.

  • To test as all the steps separately as above one by one , then you can find the problem, if not, please send us the device asap. Do remember, to test the following step in individual. You may find the problem. To follow as the pictures do.

Used in a sound installation for concert hall from our customer’s feedback

Here’s the feedback from our customer who is using a customized switching power supply D-50F15 from our company.Let’s go check this where and how he used it!

okay, it’s been a while! but as of the beginning of October 2015, i have exhibited an installation together with the artist Cecilia Sterner, at Malmö Live, which a concert hall in the city of Malmö. this project is aimed primarily at children, although not necessarily so… it was a chance to practice some subversive thinking about the organization of sounds into music, from a very fundamental angle. inspiration for this was taken from Dr. Suess, who is one of my heroes. children of a certain age have not yet been completely brainwashed with pop, or tradition, and take most things they hear with a much more open mind than adults are capable of. they will treat nursery rhymes, orchestral intruments, and noise more or less equally, provided the environment supports this. enter “KLONK!” Leta Leka Ljud.

this wasn’t meant to be so much about music, although it is musical… it is about sound. and play。

here are some images:


the basic technical solution was to use loopers and media players instead of computers… a very simple redundant structure that could sustain damage to some parts and still work, in a sophisticated capacity. i made recordings of the sounds i wanted and had them constantly playing. the LM3866 chip amp has a “mute” function which was controlled by a timer/relay switch. it’s easy to add some fade in and out time to the chip… all the parts are already in there. a little time constant and you have a smooth transition. i made 21 channels of powered speakers of various types. all the sounds were muted until some kid tripped them. then they would pop up for a fixed period. sometimes it was a little scary when that happened! all part of the dream.


the basic little “KLONKER” looks like this. the back was 1/4″ aluminum for a heatsink. i mounted the LM3866, a switching supply, fuse and a 555 based delay relay gadget. wired a trip wire to the box… boom. the full range 3″ driver is a “BMR”… a cheap variation on a Manger (no matter what the manufacturer says…). i got a bunch of them surplus and they were perfect for this. this driver is the seed for the Naim BMR driver.


here you see a bigger one.


this is a “toobapig” it is adjusted with EQ and is mounted inside the tree, which acts as a horn. it makes sousaphone like elephants on parade. not all the time! just suddenly, you heard em coming…


various bits of KLONK getting readied to go…


some KLONKERS were built into the round loops. the kids would be climbing on them and suddenly they would start clanging and whistling. there were little trip switches and actual buttons for them to find.


the hanging “ljusfrukt” had more melodic phrases… they were fun. Ed Menton built them for Cilla.


here you see the installation


weird fruit!


KLONK tree


these are “KLONKSVAMP” they are powered inverted horns with buttons to trip them. these were very popular.


these loops were super peaceful until they weren’t. kids hid inside, and then they would come screaming out of them! over and over again. super popular.


not all of the sounds were electronic! we gave the kids every opportunity to take charge of KLONK. we had to touch up and repair things regularly. those swedish kids can really run amok! love it.


opening day. we collaborated with the symphony orchestra’s musicians. everyday someone came with a flute, french horn or trombone. that was magic. they would wander around… improvising.


Cilla projected northern lights on screens hanging. the use of fabric in this piece was fabulous.

The production process of power inverter

Inverter is divided into four parts, each part to do a piece of PCB board. Respectively is the “power board”, “SPWM driver board”, “DC-DC driver board”, “protection board”.
1 power main board:
The power board includes DC-DC push-pull and H bridge inverter two parts.
The machine’s BT voltage of 12V, full power, the working current can reach 55A above, DC-DC boost part of a pair of 190N08, the 247 package of cattle, as long as the heat to do in place, a pair of you can output 600W, you can also use IRFP2907Z, the output power is almost the same price. Main transformer with the EE55 of the magnetic core, in fact, on the 600W, with EE42 is enough, I am in order to facilitate the system, plus the EE55 is there, it used the EE55. on the main transformer winding, the following details. Push-pull part is powered by a symmetrical balance way, this has two advantages, one is can guarantee high current when the second power tube work state of symmetry and ensure a unilateral fever phenomenon can not occur; the second is can reduce the PCB reverse current density of the tin layer stack, of course, can also be greatly reduced because of the interference caused by the unbalanced current. High voltage rectifier fast diode, using the TO220 package RHRP8120, the tube reliability is very good, I used a second-hand tube, only 1 yuan a. High voltage filter capacitor is 470uf/450V, in the case of possible, as much as possible with the capacity of some, to improve the high pressure part of the load characteristics and reduce interference are good.
2 SPWM driver board
As with my 1KW machine, the core part of SPWM uses the TDS2285 chip of Zhang Gong. The chip on the details, you can see my previous post: here unspecified said. U3, U4 composition sequence and dead time circuit, final output used four 250 optocoupler, H bridge of the two works, bootstrap power supply, do is simplified circuit, can not be isolated power supply.
Because BT voltage will vary between the 10-15V, in order to have a reliable driving H-bridge, optocoupler 250 totem pole output stage voltage must to between 12-15, not less than 12V, otherwise it may enable H bridge power tube failures trigger. So, here with a MC34063 (U9), the BT voltage up to 15V (the booster circuit provided by the clock), the experiment proved that this way is very effective.
3.DC-DC driver board
DC-DC boost driver board, the use of a very common line, with a PWM to achieve the output of SG3525, after the two groups of totem output, the experiment, if the use of a pair of 190N08, the totem part can be omitted, directly with the 3525 driver is enough. Because the DC-DC driver board, and my 1000W interface is generic, so there are two groups of output, the machine on the use of a set of. The board has two small button switches, S1, S2, S1 is the boot, S2 is off, you can control the start and shutdown of the inverter.
The driving plate is connected with the J3, the J4 interface and the power plate, wherein, the J3 of the 1P is limited to the input end of the pressure feedback.
4 protection board
I did not do this protection board, there are the following reasons: first, the machine can not protect the machine can work, and this period of time is relatively busy, so the protection board is pulled down; followed by: I announced the power of the motherboard, is amended, the interface also made changes to the protection board, and I use the prototype is not modified PCB board, even made a protective plate, also do not go up. I would like to have a friend if I use my PCB documents to manufacturers proofing, do not forget to give me a set of, sent to me, I can be based on the new power of the main board to draw the protective plate.

Power supply for DRC-100 series 100W track type control (with charging output)

Mingwei has been listed on the DRC-40 and DRC-60 series has been widely is used for ankong field and get a warm market response and positive evaluation. In order to meet the demand for ankong industry higher wattage, Mingwei in this family again to push up on the power, the introduction of new 100W high trust of track type (DIN rail ankong power DRC-100 series. This product is suitable for installation in TS-35/7.5 ankong internal chassis or TS-35/15 guide can accept 90~264VAC input voltage and has 13.8VDC and 27.6VDC two kinds of output voltage can be matched to a common market with 12V and 24V battery, a user can easily construct a control system of DC UPS function, especially suitable for application in must consider AC power is needed for the normal operation of the system, such as safety control system, emergency lighting system, alarm system, DC electric system, central monitoring system and access control systems.
Product characteristics:
The maximum working efficiency is 89%
No fan design, natural cooling
Working temperature: -30~+70
Warning signal: OK AC and battery low voltage (relay type)
Protection function: short circuit protection, over load protection, over voltage protection, battery low voltage cut-off, fuse by
Through UL/CUL/TUV/CB/CE certification
Dimensions (width x Height x deep) 90x 100mm:55x
3 year warranty period

The switching frequency of switching power supply

The switching frequency is said that the inverter output voltage is actually a series of pulses, pulse width and spacing are not equal. The value depends on the intersection of the wave and the carrier. The higher the switching frequency, the more the number of pulses in a cycle, the smoother the current waveform is better, but the more interference to other devices.
Nonlinear power supply, switching power supply frequency is generally greater than 20KHZ, because to avoid the sound frequency 20KHZ, the market common frequency in 50KHZ–150KHZ, generally in the 60KHZ–90KHZ, more than the 100KHZ frequency of the power supply of the switch tube requirements to be high, the cost is high, so the general will be controlled within 100KHZ
Nonlinear power supply, switching power supply frequency is generally greater than 20KHZ, because to avoid the sound frequency 20KHZ, the market common frequency in 50KHZ–150KHZ, generally in the 60KHZ–90KHZ, more than the 100KHZ frequency of the power supply of the switch tube requirements to be high, the cost is high, so the general will be controlled within 100KHZ

Generation mechanism and Countermeasures of switching power supply EMC

Classification and standard of EMC:
EMC (Compatibility Electromagnetic) is an electromagnetic compatibility, which includes EMI (electromagnetic disturbance) and EMS (electromagnetic anti harassment). EMC is defined as the ability of a device or system to work properly in its electromagnetic environment and not to constitute an electromagnetic disturbance that is not capable of any device in the environment. EMC the entire call is electromagnetic compatibility. EMP is an electromagnetic pulse.
EMC = EMI + EMI EMS: electromagnetic interference EMS: electromagnetic compatibility (immunity)
EMI can be divided into two parts, which are Conduction and Radiation. The Conduction specification can be divided into: Part 15J Class B CISPR; FCC 22 (EN61000-3-2, EN61000-3-3, EN55022) B Class; IT (GB17625, GB13837) and AV (GB17625, GB9254). FCC test frequency in 450K-30MHz, CISPR 22 test frequency in 150K–30MHz, Conduction can use the spectrum analyzer test, Radiation will have to go to a special laboratory testing.
EN55022 is Test Conduction & Test Radiation (conduction & radiation testing); EN61000-3-2 is Test Harmonic (power supply harmonic test); EN61000-3-3 is Test Flicker (voltage fluctuation test).
CISPR22 (Special des Purturbations Radioelectrique Comite) is applied to the information technology. It is suitable for European and Asian regions; EN55022 is the European standard, Part FCC 15 (Communications Commission Federal) is applied to the United States, EN30220 European EMI testing standards, power radiation testing standards are EN55013 frequency in 30MHZ-300MHz.
EN55011 radiation testing standards are: some of the high frequency requirements, some of the low frequency requirements. Conduction (150KHZ-30MHZ) to the LISN mainly is the differential current mode and the common mode impedance for a 100 ohm (50 + 50); LISN is mainly the common mode current and the total circuit impedance for 25 ohms (50 / 50).
4 line 60dB/uV 150KHZ-2MHZ start 9KHZ AV
5 line 100dB/uV 150KHZ-3MHZ PEAK
6 line 100dB/uV 2MHZ-30MHZ PEAK
7 line 70dB/uV 150KHZ-500KHZ QP
Radiated (30MHZ-1GHZ): 4N7/250V Y CAP 90dB/uV 30MHZ-300MHZ ADD
EMI is an electromagnetic interference, EMI is a part of the EMC, EMI (Magnetic Interference Electronic) electromagnetic interference, EMI including conduction, radiation, current harmonics, voltage flicker, etc.. The electromagnetic interference is caused by the interference source, coupling path and the receiver is composed of three parts of the three elements, usually called interference. EMI linear proportional to the current, the current loop area and the square of the frequency: K*I*S*F2 = EMI. I is a current, S is the circuit area, F is the frequency, K is a constant with the circuit board material and other factors.
EMI refers to the external electromagnetic interference. Generally divided into two levels of A Class & B Class. A Class for industrial grade, B Class for the civilian level. Civil to be more stringent than the industry, because of the industrial use of the allowable radiation a little big. Requirements products also products in the EMI test radiation test, in 30-230MHz class B radiation value cannot be more than 40dbm and class a request can not be more than 50dbm (to three meters anechoic chamber, for example) relative to loose the limits, generally class A is that the EMI test conditions under, without intervention from the operator, equipment can according to expected to continue normal work, not allowed to appear below specified levels of performance performance degradation or loss of functionality.
EMI is a normal operation of the equipment to measure its radiation and conduction. At the time of testing, EMI’s radiation and conduction in the receiver has two caps, representing the A Class and B Class, if the observed waveform is more than B line but below the A line, then the product is a class A. EMS is used to test equipment for product interference, observe whether the product can work normally, if the normal work or does not appear to exceed the performance of the standard, for a class. Can automatically restart and restart does not exceed the performance of the standard provisions of the decline in performance for the B class. No need to restart automatically restart C, hang D. The national standard of D level, EN only A, C, B. EMI at work frequency of the odd number is the most difficult.
EMS (Suseeptibilkr Electmmagnetic) is commonly known as the electromagnetic sensitivity of electromagnetic immunity, is the ability to resist external disturbance of the device, EMI is the device’s external harassment.
EMS levels are: A Class, the test is completed after the device is still in normal work; B Class, the test is completed or the test needs to be restarted after the normal work; C Class, the need for human adjustment can be normal to restart and normal work; D Class, the device has been damaged, no matter how the adjustment can not be started. Strictly EMI is B>A, EMS is A>B>C>D.

The design of switching power supply transformer

Switching power supply transformer is the power transformer, which is added to the switch management. In the use, not only has the function of the ordinary transformer’s voltage transformation, but also has the function of the insulation isolation and power transmission. In the switching power supply and other occasions involving the use of high frequency circuit is widely used. Switching power supply transformer design is very important to the use of the switching power supply, suitable design can make the switch power supply transformer better to control the current, the design method is not reasonable to the use of switching power supply transformer
The main materials of the switching power supply transformer are: insulation materials, wire materials, magnetic materials. Switch power transformer with the switch tube together constitute the self-excited or his excited intermittent oscillator, the DC voltage modulated into a high frequency pulse voltage and finally to energy transfer and conversion. When the switch is switched on, the transformer converts the electric energy into a magnetic field to store it, and when the switch is cut off, it is released. In the forward circuit, when the switch is turned on, the input voltage is supplied directly to the load and the energy stored in the energy storage inductor. When the switch is cut off, the energy transfer is carried out by the energy storage inductor. More simply, the role of the switching power supply transformer is to convert the input DC voltage into the low pressure needed in our use.
In the design of the structure of the switching power supply transformer, we should consider the following points, leakage magnetic must be small so that the leakage inductance of the winding can be reduced. In the structure design to make it easy to winding and lead the way so that the transformer is not only simple and convenient, but also for the maintenance and production of the transformer is very helpful. In the design of a reasonable plan, so that the voltage can have sufficient space and function for cooling. If the design of switching power supply transformer on the full consideration of the above factors, then this design can make the switch power transformer more secure, more durable life.
In the design of switching mode power supply transformer when the material choice is very important, and in the choice of core is switch in power transformer, according to the choice of switching power supply transformer use different materials are also different. For use in the us the most extensive core is iron, manganese, and zinc oxide core used in the power supply input filter is used to high permeability core. Because of the low price of soft ferrite, good adaptation and high frequency performance, it is widely used today.
Switching power supply transformer design has certain requirements, these requirements can make it achieve the best use effect. The first is that the leakage inductance is small, because the voltage spike of the switch is connected with the size of the voltage spike, the circuit condition, the collector circuit configuration and the leakage inductance. Secondly to avoid transient saturation, in instantaneous electrical transformer core serious saturation will produce great surge current, in a very short period of time may cause the switch tube damage, generally in actual use will install soft start circuit to solve the problem. The effect of temperature is also considered in the design.
The detection method is very important in the use of the switching power supply transformer. In the detection, it can be seen whether there is an abnormal phenomenon, and the insulation of the switch power transformer is tested by the test. The above is a small series of switching power supply transformer is a brief introduction, we want to help group.

Dual power supply

Double power supply automatic switch is refers to a controlled by a microprocessor for grid system net power and electric or electric network and power generator start switching device, can make a continuous source of power supply. A series of dual power supply, when the power of a sudden failure or power failure, through the dual power switch, automatically put into standby power, (small load of standby power can also be supplied by the generator,) so that the equipment can still run normally. The most common is the elevator, fire control, monitoring, lighting, etc..
Dual power switch electrical appliance (converting switch) converts one or several load circuit from one source to another. By one (or a few) conversion switch electrical appliances and other necessary electrical components, to monitor the power supply circuit, and one or several load circuit from a power supply automatically converted to another power source. Electric industry is referred to as “dual power automatic conversion switch” or “dual power switch”. The national standard of ATS products is defined as a (or several) switch electrical apparatus and other necessary electrical components for detecting power supply circuit, and one or more load circuit from one power to another power supply, ATS is suitable for the construction field fire and other key load power supply, EPS is suitable for EPS is to solve the emergency lighting, accident lighting, fire facilities and other load power supply equipment as the main goal, to provide an emergency power supply system with independent loop specifications. UPS is mainly for the IT industry equipment to provide electricity, to provide a clean, uninterrupted power supply. Diesel generator power supply mode is suitable for the use of EPS, UPS and ATS in the power supply place with long time standby power supply.

The difference between isolated and non-isolated

There are several trends are driving the development of LED lighting market. First of all is the high brightness LED efficiency of continuous improvement and very high reliability and high reliability of constant current LED driver power supply continues to emerge, followed by the global legislation to ban incandescent lighting (due to its low efficiency) and CFL energy-saving lamps gradually fade out (if broken, it will flow out of the environment harmful mercury). These factors are combined to make LED lighting become a long-term development trend. Of course, low system cost (including LED, thermal management system and LED driver) will always be the driving force for the wide use of LED general lighting. In fact, in many LED lighting products, failure is a common phenomenon, most of which is because of the failure of the power, rather than the failure of LED. At the design level, this means that the OEM must become a hot design expert. LED provide high efficiency, but they are also more heat than incandescent or energy-saving lamps. Because many LED lighting applications are enclosed in a very small space, it is difficult to use ventilation to heat dissipation. If there is no careful thermal design, the LED and the power drive circuit is easy because of high temperature and degradation or permanent failure.
As a product that allows the end user to be safe, it must consider the reliability of insulation and isolation. As a complete product, the surface of the product can be exposed to the part of the user must be isolated, can not let people get electric shock. And from the whole system, the isolation is inevitable, the difference is only set the location of the isolation. Some designers use isolated transformer design, so they can simplify the design of cooling and lamp shades. If you use non isolated driver design, the lights on the shell structure of the insulation requirements must be considered reliable. As a result of power supply, the isolation and non isolation schemes are all the same. The main challenge for the Chinese LED drivers is to find a low cost AC/DC driver, which can meet the performance of more stringent power factor and efficiency in low cost power supply system. In the future, the use of high quality, high reliability power supply will be no longer free of charge in the space constrained and there is a cooling system (such as LED lamps). However, in the end users have used a lot of life in 10000 hours or so…
LED driver power isolation and non isolation 7-5 is currently in the general LED lighting market, there is a non isolated design and isolated power supply. Non isolation design is limited to a dual insulation product, such as a light bulb replacement product, where the LED and the entire product are integrated and sealed in a non conductive plastic, so the end user does not have any risk of electric shock. The two level products are isolated, the price is relatively expensive, but in the user can be exposed to the LED and the output connection (usually in the case of LED lighting and street lighting applications), this product is essential. LED driver power supply with isolation transformers or electrical isolation means that the LED can be directly touched by hand without electric shock. Without the isolation transformer LED drive power still can with protective casing, so as to realize the mechanical part of the insulation, but this time the LED at work and not direct contact. Insulation type light bulb in the future will become the mainstream. Physical design determines that the drive is an isolated or a non – isolated. Safety rules usually require the use of two separate isolation layers. The designer can choose two kinds of physical isolation layer, or plastic mask and glass cover, and use of non isolated power supply. If the cost of physical isolation is too high, there is a mechanical difficulty or absorb too much light, it is necessary to solve the problem of electrical isolation in power. Isolated power supply is usually more than the same power level of non isolated power supply. Lighting designers must be in the design of each product in a lot of cost and design optimization work. Because it is suitable for different applications, it is a protective shield that is used in isolation. In general, they will be analyzed in many ways, such as cost and manufacturing process, efficiency and volume, reliability and safety requirements, and so on. With the high cost of the transformer, but also to make the LED lamps become more practical, to meet the needs of the end user to meet the needs of LED. When the incandescent lamp glass shell is easy to damage, a E27 type of ordinary light bulb can be replaced with LED lights. In addition, in the industrial area or office equipment in the application of the lamps do not need to contact the end user, such as street lamps and shopping malls lighting, then the LED lights do need to isolate the transformer.

The protection level of switching power supply

IP is internationally used to identify the protection level of the code Ip level by two figures, the first digital representation of dust; second figures from the representation of water, the greater the number of figures, said the leader is better.
Definition of number protection
0 no protection without special protection
1 to prevent the body from more than 50mm to prevent the human body due to accidentally touch the internal parts of the lamp to prevent the diameter greater than 50mm of the object
2 to prevent the object from more than 12mm to prevent the internal parts of the finger to prevent the finger
3 to prevent more than 2.5mm of the whole body to prevent the intrusion of the diameter is greater than the 2.5mm tool, wire or object intrusion
4 more than 1.0mm objects to prevent intrusion prevention diameter greater than 1 of mosquitoes, insects or invasive objects
5 dust can not completely prevent dust intrusion, but the amount of dust will not affect the normal operation of the lamp
6 dust completely prevent dust intrusion
Waterproof grade
Definition of number protection
0 no protection without special protection
1 to prevent the drip of water from the vertical drop
2 tilt 15 degrees when the lamp is still to prevent water intrusion when the lamp is tilted 15 degrees, can still prevent dripping
3 to prevent the injection of water intrusion into the water, or the vertical angle is less than 50 degrees in the direction of the water jet
4 to prevent the splash of water intrusion prevention of the direction of the water intrusion
5 waves of water to prevent intrusion prevention or blowhole rapidly from waves of water intrusion
6 to prevent water intrusion into the water waves lamps in a certain period of time or pressure conditions, to ensure the normal operation of the lamp can be
7 to prevent the intrusion of water into the lamp without a period of water in a certain water pressure, and can ensure the normal operation of the lamp
8 to prevent the impact of the sinking