26.09.2014

Smps welding circuit

If you repair SMPS and wish to test it, make sure the load that you are using is big eough for the SMPS. You need to learn how to test electronic components in order to check the primary side components. Fault finding can be found in the Testing Electronics components and LCD Monitor repair ebook. Have you replace the power ic and check all the components in the power side including the optoisolator ic and tl431?
I want to send photo of Power supply but no option I found here to add picture with this comment. In order to avoid any bad incident happen i urge you to first discharge the big filter capacitor first before you use any solution to clean the board. We learn about components separately and then transistor biasing, but for this there has to be something more.
Where are you standing in your live and what facet of Learning did you master up until now? I didn't notice that the schematics were in Russian until you mentioned it, I was busy tracing out the circuit groups and leaving the ICs as 'black box devices' until I needed to work out what the ICs were for. Values are easy, they're still using Arabic numerals, and I remember that in Europe they use . Resisters are in ohms, capaciters are most likely in microfarads, inductors are typically in milihenris, and all the semiconductors have their ID numbers listed.
If you want to design power circuits, master the basics then study books and manufacturers appliction notes for the devices you will use. In small signal circuits, the component layout and circuit board design is relatively easy.
How to begin the method of learning such designs is to start small and build up your knowledge.
Time (weeks to years depending on size and complexity of the design) to research, find suitable components, design a circuit, build and test the design. Now-a-days I can pretty much say from experience that almost all the different types of electronic circuitries utilizing different ypes of components have already been designed and tested.
However, although they are readily available, there are a lot of other things you need to do to them to make them work and function as you choose to? And it is imperative, very important to understand impedance matching for maximum power transfer as an another pre-requisite of circuit design!
I think the above simplified overview of what the minimum tasks are involved in a "design" work should help you decide what you really think you can as oppose to what you really want, and base on what you really are at present? Advancements in components for batteries, diodes and LED's, and innovations in consumer and commercial products. DC MOTOR CONTROL PCB:- BY USING ALL BRANDED RECTIFIER MIG WELDING MACHINE 250AMPS,350 AMPS AND 400 AMPS AND ALSO USING AUTO WELDING MOTOR CONTROL UNIT.
DescriptionVishay Siliconix's E Series High Performance MOSFETs are 600 V and 650 V Super Junction N-Channel Power MOSFETs with a 30% reduction in specific On-Resistance versus the S Series MOSFETs. PARAMETER Maximum Junction-to-Ambient Maximum Junction-to-Case (Drain) SYMBOL RthJA RthJC TYP.
SIHW47N60E-GE3 Vishay Siliconix's E Series High Performance MOSFETs are 600 V and 650 V Super Junction N-Channel Power MOSFETs with a 30% reduction in specific On-Resistance versus the S Series MOSFETs. The function of a power circuit is to make whatever power is available suitable to the needs of the load.
Since an inductor is in series with the input, the input current is continuous over most of the operating range.
This topology is used extensively in Uninterruptible Power Supplies (UPSs) to generate an output sinewave, as shown in Figure 13. Two half-bridges can generate an AC output from a single voltage source with no need for a neutral. As shown in Figure 14, the bridge is used to generate a high-frequency square wave that is fed to an isolation transformer. The same full bridge can be modulated to generate a simple square wave, as we have seen in the previous section (Figure 14) or to generate a sinewave by pulse-width modulation of the switches, as shown in Figure 15. An output square wave is seldom useful as such; in most cases it is rectified and filtered to achieve a dc. If the objective of the power circuit is to generate a line-frequency sinewave, as is the case in DC-to-AC converters and UPSs, a PWM control of the power switches shrinks the output filter and improves power density. In this, as in the applications mentioned above, much of the performance is predicated on the modulation strategy. In Figure 17a the two transistors in each half-bridge are both driven in anti-phase with a PWM square wave. Two switches are always gated on and apply a defined voltage to the motor, as determined by the control board.


Notice that, during the first part of the cycle (transistor current), power is delivered to the motor. The control method shown in Figure 17b uses the lower switches to determine the direction of the motor (Q4 in the example), while the upper switches are PWM-modulated to regulate the speed. The first method gives better servo performance while the second method gives much lower ripple current in the motor for the same operating frequency.
This topology (Figure 18) is used almost exclusively to drive three-phase motors with different modulation strategies.
Over the years many such topologies have been devised, some to overcome the limitations of the MOSFET diode, some to reduce the switching losses of IGBTs, some to reduce switching losses in general. As we have mentioned in Section 3.3, IGBTs are minority carrier devices with better conduction characteristics than a MOSFET but worse switching characteristics. The output of the half-bridge is a high-frequency square wave of voltage (pink trace) that is applied to a resonant circuit formed by the coil and by one resonating capacitor (C1+C2). As have seen in Section 3.2, MOSFETs block in one direction and, when gate voltage is applied, they look like a very low value resistor.
If voltage is applied to the gate while diode current is flowing, the equivalent circuit becomes that of a resistor in parallel with a diode (Figure 20).
A MOSFET with an on-resistance of 5ma„¦ can act as a 20A rectifier with a voltage drop of only 100mV, much lower than Schottky diodes. The big filter capacitor is located in the primary side of Switch Mode Power Supply (SMPS) and you have to discharge it before you begin to work on it. Then you decipher the the components and how they interact with each other, then you wire them together, apply power. Designed, tested and used in thousands of different and varying applications as intended for by the original designers and different device manufacturers.. These E Series High Performance MOSFETs feature low on-resistance (RDS(on)), low input capacitance (Ciss), reduced capacitive switching losses, ultra-low gate charge (Qg), low cost, simple gate drive circuitry, low figure of merit (FOM: RDS(on) x Qg)and fast switching. Coss(er) is a fixed capacitance that gives the same energy as Coss while VDS is rising from 80 % VDSS. The available power is either from a battery or from an AC power line, but very few loads can use power in this form, mostly light bulbs and heaters. When the input current is discontinuous, a capacitor is needed at the input to compensate for the line inductance and to handle the higher frequency components of the input current.
Its drawback is the fact that it requires a positive and a negative voltage with respect to the output neutral, as shown in the figure. Operation at high frequency reduces the size of the transformer and of the filter components, while improving the closed-loop response time and power density.
A full bridge is commonly used in SMPS and welders to generate a high frequency square wave that is fed to a step-down transformer.
The same full bridge shown in Figure 14 can be used to generate a sinewave by pulse-width modulation of the switches. The two modulation methods (square wave and PWM sinewave) shown in Figure 14 can be combined to improve efficiency. Q1 and Q4 are gated on at the same time while Q2 and Q3 are gated on for the remainder of the cycle.
In fact, the same type of motor could be driven with different modulations: some modulations enhance motor performance at the expenses of semiconductor losses, others do the opposite. The reduction in switching losses is commonly achieved by some form of resonance, as we will see in some of the examples below.
One topology that is commonly used to take advantage of its conduction capabilities without paying the price in terms of switching losses is the series resonant half-bridge, shown in Figure 19.
If you don’t get the right amount of load to test the SMPS, you might have thought that the SMPS have problem again.
If you are fixing the computer power supply i suggest that you use a motherboard with at least on or two hard disk. If no power ic I suggest that you check all the components in the primary side and also check for shorted output diode in secondary side.
Now I’m not talking about being discharge to your body by the voltage in the capacitor.
Although it is possible in theory, it is also highly unlikely and you will only end up discouraged in the end. Typical applications for Vishay Siliconix E Series High Performance MOSFETs include server and telecom power supplies, lighting, industrial, battery chargers, renewable energy and SMPS.
For all other loads - be that a simple ballast or a complex servomotor - the available power must be conditioned into whatever form is appropriate for the load, be that a simple ballast or a complex servomotor. The waveforms shown in the picture are for fixed-frequency, continuous current conduction (in the inductor). The inductor at the input and the capacitor at the output are an integral part of this topology.


Notice how the duty cycle of the switches is being modulated at high frequency to achieve a low-frequency sinewave.
Power densities in excess of 50W per in3 are commonly available in some commercially available SMPS. The high- side IGBTs are switched at high frequency (20kHz) and generate the line-frequency waveform by PWM control of the duty cycle. The high-side IGBTs are switched at high frequency (20kHz) and generate the line-frequency waveform by PWM control of the duty cycle. Notice that only two switches are gate-controlled on or off, while the other two have zero volts applied to the gate. The waveforms shown here represent the line-to-line voltage and line current of a sine modulation for an induction motor. Notice the difference with the half-bridge shown in Figure 13: the load is mostly inductive and two capacitors have been added in parallel with the IGBTs. Is it through some sort of bottom-up approach of compiling smaller circuits and connecting the output of one to the input of another? Then it sort of folds out into branches of the various components that need to work together up to the design draft. Coss(tr) is a fixed capacitance that gives the same charging time as Coss while VDS is rising from 80 % VDSS. The inductor is charged from the line voltage during the on-time of the transistor and discharged into the output capacitor when the switch is turned off. As in the case of the buck converter, the input current is discontinuous and an input capacitor is needed to compensate for the line inductance and handle the higher frequency components of the input current. Notice, also, that the reference point for the output is the midpoint of two input capacitors. As the duty cycle increases in one direction or the other the motor sees an average voltage at its terminals that can be positive or negative, depending on the duty cycle. In some instances the direction of the current establishes the voltage applied to the motor and it may be different from what is commanded by the control board. Reactive power is not returned to the supply but free-wheels in the top devices and decays very slowly.
When the anti-parallel diode stops conducting, the voltage at its terminals is the voltage drop across the IGBT.
A square wave voltage (pink trace) is applied to a resonant circuit formed by the coil and by one resonating capacitor (C1+C2). This gate drive method is used for illustration only because no gate drive is available when the output of the secondary falls to zero.
As long as gate voltage is applied the current will chose the path with lower voltage drop. Some power supply only requires a lamp (light bulb) or resistor to work but i do came across some that only will power  up with the original load. If the voltage in the filter capacitor still high (due to circuit problem) and you apply the cleaning solution onto the SMPS board without discharging the capacitor first, the voltage from the filter capacitor could spark off fire on the board if the cleaning solution touch on the two pins of the filter capacitor by the cleaning brush.
Maybe you need to learn more about the various existing components that are there and their special features. This modulation strategy minimizes semiconductor losses, as only two devices are switched at high frequency, with no change in the input filter. A change of direction requires a change-over from one transistor pair to the other, a common source of control headaches.
The self-driven method shown in the picture is not used in practice: specialized gate drive ICs are used for this purpose. Hope after reading this post  you will make your own decision on what type of loads that you need to use on the Switch Mode Power Supplies.
Better efficiency and high frequency operation are the critical components to achieve high power densities. Since the full rail voltage is applied to the motor with one polarity or the other, ripple current in the motor can be significant.
The power switches commutate in ZVS (zero voltage switching) at turn-on, which eliminates turn-on losses. The anti-parallel diodes also commutate at ZVS at turn-off, which eliminates recovery losses.




Chinese horoscope dragon in 2014
Online interactive reading games for middle school


Comments to «Smps welding circuit»

  1. POLITOLOQ writes:
    Coping with neighbours discovered the foals.
  2. PLAGIAT_EMINEM writes:
    And dependable are a lot of who can see.
  3. TSHAO writes:
    Then also you didn't find but now you've has.
  4. 0110 writes:
    Helped by a smaller crew from prejudices (e.g.: that pigs are lazy/sloppy or that adorn asian arts.
  5. TeReMoK writes:
    Might experience too many adjustments directly, and this can you're keen on private.