Switching power supply failure check

The principle of the switching power supply is roughly the same HP3748 printer supporting voltage output switching power supply manufacturer, for example, where the works of friends troubleshooting method to explain the switching power supply. Understand the working principle If you want to learn to rule out the failure of the switching power supply, we must first understand the working principle of the switching power supply, and which components are easily damaged. When the mains input from the input, first to the capacitance and inductance L-type or -type filter circuit for filtering, to eliminate the surge in the mains voltage and interference signals, improve power quality.
The same time, in the mains input is also connected in series with the fuse when the power supply short circuit fault, the fuse blows, to avoid failure expansion. And now most of the switching power supply input and a varistor. This resistance when the voltage is normal, resistance is infinite, does not affect circuit operation. Once the voltage is too high, the varistor will short-circuit, so that the current increases through the fuse, the fuse fuse, to avoid damage due to high pressure caused by other components.
After the filtered alternating current through the diode bridge rectifier circuit and the high-voltage large-capacity capacitor filter to generate 300V high-voltage DC voltage, the voltage by the resistance of the step-down and simple regulator into the oscillation control circuit to generate the oscillation signal generated oscillation signal by the amplification of the power oscillating tube with high-frequency transformer, will be transformed into low-voltage AC voltage, low-voltage AC voltage to a rectifier filter, you can generate a variety of available devices use low-voltage DC. In addition, the output of the main voltage with voltage sampling feedback circuit, the current voltage is fed back to the oscillation control circuit, once the main voltage due to load changes and voltage drift, the oscillation control circuit will change the oscillation pulse width to ensure that the output voltage stability. Meanwhile, when the load short-circuit, sampling the feedback signal will promptly notify the oscillation control circuit to stop the output of the voltage, to avoid power overload and damage. Fault detection method With a basic understanding of the switching power supply, we take a look at the method of fault detection and repair. Should first be observed that the power supply fuse is damaged. If the fuse is damaged, can not rush to replace, you must first check the power supply if there are short-circuited. :
Multimeter electrical AC-side barrier test power fuse (test point), its normal resistance should be more than tens of kilohms, such as resistance to zero, then the power supply to the existence of exchange short circuit. In addition, we should focus on examination of power AC filter capacitor is damaged; varistor should also check this resistance. If the test is normal, we shall then detect power four rectifier diodes (test point). In the normal state, the forward resistance of the diode number k (with multimeter 1k block test) and reverse resistance approaches infinity. If the test results are not normal, you need to be replaced. Down the investigation down, and then have to do is to test the power of the DC resistance of this part (test point), its normal resistance is also the number of k, such as the resistance is zero, indicating the presence of a DC short circuit. The reason for the DC short circuit is more like a filter capacitor short-circuit damage, the power oscillation tube damage, the oscillation Manifold and the peripheral circuit part damage may cause a short circuit phenomenon. In this note is to replace the power oscillation tube, you must determine the oscillation Manifold and the external circuit, otherwise it will cause the power tubes damaged again. Exclude the above-mentioned problems of the switching power supply, indicating a fault exists in most of the oscillation control circuit, sampling the feedback circuit or load. At this time, we should first check the power supply circuit of the oscillation Manifold normal (test point), its normal voltage should be around 10V (to remind: the test voltage in the power case, the power supply board with high pressure the mains, so pay special attention to personal safety, and not attempt to directly touch any part of the power). Such as the point of no voltage or voltage is very low, we must first check the dropping resistor is not damaged; check the the oscillation Manifold and its external power supply circuit. No fault found, such as peripheral circuits, the proposed replacement of the oscillation Manifold. Of course, sometimes the power can not be the normal output voltage may be due to the load short-circuit power protection caused. This power, we only need to disconnect the output line, check the output voltage is normal (test point), you can determine the fault position. Front of troubleshooting, the final should also check the feedback circuit section, in general, this part of the fault is mainly concentrated in the optocoupler and amplifier, with particular attention.
Summary Of course, the above method can not solve all the problems of the power supply, but is effective for switching power supply daily are more prone to some problems. Hope that through this presentation, can play a valuable role to help solve the minor problems encountered in switching power supply More information about Fiber Optic Connector and sensor supplier in cpbay.

Analysis for thermal radiation of LEDs

 Until now, many people believe that LED high bay has no thermal radiation. Is it true? Firstly, there are some concepts need to be understood: What is LED? LED is the abbreviation of Lighting Emitting Diode, a fully packaged electric component including chip, base, wires and colloid. LED is constituted by multiple materials, not only PN junctions. Until now, many people believe that LED has no thermal radiation. Is it true?
What is the lighting principle of LED Panel Lights? Within LED PN junctions, rays are generated though the combination of electrons and holes. When an electron is captured by a hole, this electron will drop from conduction band to valence band. During this process, the released potential energy converts into optical energy. In ideal condition, all of the potential energy will convert into optical energy since energy cannot be divided. Thus in ideal conditions (without any impurities and defects in diodes), there is no thermal radiation for LEDs, except for some special LEDs, like infrared diodes.
What is the meaning of thermal radiation? Objects above absolute zero will inevitably generate infrared rays, namely thermal radiation. Generally, thermal radiation in real life is the thermal influence of objects when they have a higher temperature than surroundings. What is cold light source? Cold light source can emit rays without heat. Bioenergy, chemical energy and electricity can stimulate its internal electrons transition to emit rays. Now let us discuss about the original questions: does LED really have thermal radiations? As we mentioned before, in ideal conditions, there will be no heat generated during the combination of electrons and holes. But, chip has resistance, the internal potential of PN junction will obstruct the movement of electrons (make negative works), electrodes have resistance, chip base has resistance. All of these will generate heat due to the external electric field, leading to the entire china led manufacturer component has a high temperature than surroundings and consequently thermal radiations. Lighting principle is different from heat generation.
They are two distinguished properties of LEDs. It is completely wrong that LED has no heat generated since there is no vibration (heat) in the light-emitting process. PN junction is not the only part of LED, there are many other parts. As multi-materials components, thermal radiation for LEDs is inevitable. Cold light source still generate heat. More information about power supply and sensor supplier in cpbay.

Ceramic-faced Sensors Stand up to Welding Processes

Inductive proximity sensors in a welding environment face a variety of hazards.  Hot metal particles – called weld spatter – are ejected from the welding process and can melt or burn their way through unprotected plastic sensor faces.  Built-up weld spatter (often called weld slag) can eventually cause a sensor to trigger on falsely.  If the slag can’t be removed, the sensor has to be replaced.
One solution to these issues is sensor manufacturer made with tough ceramic faces.  The ceramic face stands up to the hot weld spatter without melting, and doesn’t provide a good surface for slag adhesion.  Even if slag does build up on a ceramic face, it can typically be removed during maintenance without the need for sensor replacement.

Sensors in a welding environment are also subjected to impacts from part loading.  In the case of a ceramic-faced sensor, what happens if a ball of weld spatter is sitting on the face and then a heavy part is loaded on top of it?  Could the ceramic face crack?  Given enough force, it certainly could.  But ceramic sensors can be designed to withstand a reasonable amount of force without damage.
This video demonstrates impact testing of a ceramic-faced sensor by a test weight having a ball-shaped tip.   The ball-shaped tip simulates a ball of weld spatter sitting on the sensor distributor face, which is suddenly impacted by a part being loaded on top of it.  In this test, the ceramic face has sufficient resilience to withstand the impact without sustaining damage.
from:http://sensortech.wordpress.com/2011/04/06/ceramic-faced-sensors-stand-up-to-welding-processes/
power supply manufacturer from Cpbay B2B MarketPlace

Its High Time to Switch to LED Lights

With increase in population all over the world, there has been great increase in consumption of energy of as well. Thus, day by day the scarcity of electricity has been increasing drastically. For your future generation to have electricity for their basic needs, you need to start conserving electricity from this moment. There are various ways in which you can conserve electricity. The best and most recommended method is to replace all the traditional lights with LED ones. As part of electricity conservation, you can now come across LED traffic lights in most of the cities.
In case of traffic led light manufacturer with incandescent bulb, most of the energy taken in by the bulb is given out in the form of heat. In case of LED bulbs, only 40% of the electricity taken in by traditional lights is sufficient to deliver light of same intensity. Traffic lights must work 24/7. Thus, in case of incandescent traffic lights lot of electricity gets wasted. In order to avoid such wastage people have now started replacing incandescent traffic lights with LED ones.
Not just in traffic lights, led lights have replaced traditional lights even in offices, hospitals, shopping malls and even in houses as well. There are various personal and environmental benefits that you get by switching to LED lights. LED lights saves your hard earned money by reducing the electricity bill to great extent. In addition, as these lights have high longevity, you will not have to spend money as replacement or operation cost.
On the other hand, as these do not contain any toxic substance like lead and mercury, they arent harmful to environment as well. Thus, these led light bulbs are definitely a boon in this world of increasing energy crisis. Hence, replace all traditional fluorescent and incandescent lights with Light Emitting Diode lights to enjoy the benefits that you get out of it.

related from:http://www.crackingchrisshort.com/its-high-time-to-switch-to-led-lights/

When Purchase LED Light

You have may have heard that Led downlight are price saving, energy saving and environmentally friendly. Yet whenever you venture down towards the shop (or on-line website) to purchase them, you had better know what you’re doing or you might just end up using the incorrect bulb. There are 5 key issues to look out for:
Initial, make sure you know what type of bulb you wish to replace. This sounds very straightforward, but just as we joke about computer customers phoning the assistance line to say their pc isn’t working, simply to realize they had not plugged it in, selecting an Led spotlight requires which you know a) the base dimension and fitting kind (i.e. is it a screw fitting or bayonet fitting; is it a thin candle kind led lights or a standard incandescent globe etc.).
Take note from the dimensions of one’s bulbs and also take not from the space within a lamp shade or housing. Whilst LED fluorescent lamps are designed to closely resemble more traditional lights, right now there may be differences in size.
A ten lumen light will provide negligible light (barely sufficient to locate your way about a space) while a 3000 lumen light will allow you to read a book in a space. The cause for this really is that unlike incandescent lights, like a 60W or 100W bulb, which radiate comparable numbers of lumens, led lighting can have very various lumen outputs (a W or Watt, is simply a measure from the energy needed to light your bulb).
To replace an 80W light bulb you will need to find an LED light that provides 600-700 lumens of light. Now if this is not stated on the packaging, you will have no idea what you are actually buying. There might be anything from 5W to 13W LED lights on the shelf so you will have to ask an assistant for the led light manufacturer lumen output.