| |
3500W 6000W high-grade analysis of switching power supply
American and German companies on the key components of high power and high frequency switching power supply using advanced technology lessons. You can expect, 3500W power main power transformer instead of the traditional General EE85 thick ferrite cores, not only in size and weight will increase exponentially, overload and saturation capability will be significantly reduced, under the impact of the power surge damage chances of MOSFET power greatly increased. Development by the Ascom 6000W-48V/112A power power supply, its main transformer Panasonic Lumix DMC-ZS5 Battery Charger magnetic cores to three 73mm flat magnetic rings superimposed, the stunt is too clever, unique and profound, is worth learning to adopt.
2.3.2 square iron shell energy storage inductor Boost converter
After disassembling found that the structure and selection of novelty. 350V/10A Power Boost inductor using three 6 EE55 ferrite magnetic core compound formed, but its center column gap of 5.2mm (each block is 2.6mm). Boost storage can inductance device of winding wire does not with General of more unit φ 0.47mm enameled wire winding, but used two section very thin of (thickness only 0.1mm), and width 33mm red with stack-in, each section thin copper with total long about 6.5M, stack-in pressure tight in (can plug 6 block EE55 cores of) plastic skeleton Shang total around 26 ring, then received solder wire leads, with multilayer resistance high pressure insulated tape breechesgathered package. This special copper strip processing amount of Boost energy storage inductor winding = 267 μ h, Q=0.36, to reduce the high frequency skin effect, improving modulation waveform, reduce the magnetic switch Boost converter temperature rise has an important role.
This is a major technological innovations never before seen. Power over the years in the technical papers about PFC-Boost magnetic design papers have not yet seen this report. A few years ago when I was in the 2000W-PFC test for several large iron-cored magnetic ring or with a large tank-shaped ferrite cores to increase air-gap, Boost energy storage inductors wound are still too fast, high fever, the effect is not ideal. Are subject to a great deal.
2.3.3 additional resonant inductor
When desoldering 350V/10A power, find the main power transformer primary winding attached in series resonant inductor, is a diameter of φ? 33mm, SI-magnetic loop, winding with multiple thin line around the 3.5 times, inductance is 3.2 μ h. Desoldering 6000W power supply 350V/17A-output, the original side of the additional resonant inductor is connected with 42mm of Fe-SI-Al magnetic ring. Test a few years ago with 1000W, 2000W, 3000W power, plus the EE55 air gap, EE65, doing additional resonance of EE70 ferrite inductors, one size smaller than the main power transformer cores only, and the temperature rising higher. Instead, SI magnetic ring, weight and volume can substantially reduce the additional resonant inductors, was found and a new technology.
To accurate draws two species 3500W power Board Shang of all components welding points location, printed board copper foil go line, to painting out real of power circuit design figure, I advance measurement size, as avoid welding points, in Board Middle location saw open has printed Board (thick 2mm of glass fiber bondedto), finally by 1:1 of actual ratio, with 2 Zhang A4 copy paper to draws out power Board positive components layout figure, and two block control board welding points location,. Using 2 pieces of A4 paper draw the back of the power supply Board printed circuit board copper foil alignment and a number of SMD solder resistance Nikon MH-63 Battery Charger capacity, many perforation positioning. And preliminary maps 3500W power main power circuit, as shown in Figure 1. Two kinds of structure similar to the design of the power supply, and gives a total block diagram of Figure 2 relationship with PFC, full-bridge control board.
3 GB features and analysis of two kinds of main circuit
From entity Anatomy, and split welding draws 48V/70A communications power and 350V/10A special power Board Shang of all components, and printed board copper foil pros and cons on both sides actual go line, and many welding points of real positioning (some perforation, and some does not perforation only in single), this painted out of Figure 1 main power transform circuit diagram, and Figure 2 power total structure diagram and PFC, and full bridge control board mutual relationship, see a general law.
1) two very different 3500W DC output voltage and current high-end power supplies (Vo, Io is about 7 times times), the three pillars of its main power converter circuit is basically the same, that power input filter rectifier; PFC Buck-Boost combinational circuits section of the system control, and full-bridge converter with soft switching circuit of ZVS phase-shift control.
2) PFC SMD components of two power control board is exactly the same. 8 IC and hundreds of resistance-capacitance. Including PFC Control Panel and motherboard connections dual core-plug 16 leg are exactly the same. High density thick 1.0mm PFC Control Board only, but the autopsy found printing plate and two mezzanine circuit design.
3) both SMD components and high-density full-bridge controlled entities are not the same, its main chips are made of UC3877. 48V/70A power full-bridge control board single components. Welding SMT components on both sides of the total area of 350V/10A power full-bridge control panel in 1 time; sandwich for PCB copper foil alignment of single components are more simple. Two power socket shell monitoring circuit structure is different. 48V power supply full-bridge on the control panel with the main chip of UC3877DWP combined with 7 other IC is only LM339X2,74HC05,74HC86,LM358X2,MAX875. 350V power full-bridge control panel with the main chip of UC3877DWP combined with an additional 8 IC is OP177G, the AD620, LM393X3, LM358, 74HC05, 74HC86 etc. Power long 70cm 48V/70A communications, board space comfortable. The power Boost energy storage inductor cores, however only two blocks of 4 EE55, power capacity is small, has two power supply blown up Boost? MOSFET, is a design mistake.
4) 350V/10A power supply entities under Add active clamp circuit after the rectifier, Deputy for soft switching power converters, significantly reduce the high frequency noise of the power supply unit under no load conditions. Especially 350V Power Boost of energy storage inductor design is the use of three 6 EE55 core portfolio (air gap 5.6mm Center column), did not find a 350V fried Boost-MOSFET. Description of the thematic design group has successfully.
Table 1 and Figure 3 respectively to an 350V/10A power was under no load conditions, instrument and measurement of print data and waveform. Figure 4 shows and after load-400W power input current and voltage waveforms for measuring print, power numbers, frequency characteristics.
IBM, the Ascom supply three-phase input power, subtly broken down into two single phase input, and then separately as a full-wave rectifier, which managed only. This has a major advantage on the high power switching power supply design and practical value. Output voltage up to DC760~800V ordinary three-phase PFC converters (some even DC1000V) this requires the back-stage converter with power switch tube voltage up to DC1000~1200V. Therefore, popular on the international study on three-level soft switching converter to overcome the challenges, it needs more JVC BN-VG114U Battery Charger in-line a switching valve reduces reverse voltage, the circuit components and significantly increased costs. IBM independence developed a new way, using a simplified method to solve the problem. Figure 4 load waveforms. Figure 5 shows 350V/10A power in 4 different load conditions, measuring print grid input current and voltage waveforms.
With DPM notebook PC battery charging controller/selector
Bq24700/bq24701 is designed for notebook PC tailored to highly integrated battery charge controllers, and selector. Bq24700/1 uses its dynamic power management (DPM) and AC wall adapter to automatically adjust the charging current of the battery, thereby minimizing battery charge time, and the choice of low-cost adaptor. Bq24700/1 selector lets you choose on the battery or AC wall power adapter as the primary system. 300kHz fixed frequency and PWM can be used simultaneously to accurately control the charging of the battery current and voltage. NI-CD/Ni-MH batteries and Nikon EN-EL11 Battery Charger lithium-ion/lithium polymer battery pack (package) charging, charging current precision of ± 4%. When the Li+ battery charging, charging voltage accuracy of up to ± 0. 4%. PWM controllers devices suitable for the wall adapter voltage is higher than the battery voltage in the case of buck converter. In the discharge of the battery case, in order to protect the battery, bq24700/1 executable detection and indication to drain the battery.
2 pin features and recommended operating conditions
Bq24700/1 with 24-pin TSSOP package, pin arrangement as shown in Figure 1. Table 1 lists the PIN functionality.
Table 1 bq24700/01 pin functions
Bq24700/1 the recommended operating conditions are as follows:
Power supply voltage (Vcc): 7~20V (select operating voltage of 4. ５～２０Ｖ)；
ACN, and ACP (11 feet, 12 feet) input voltage: 7~20V;
SRN and the SRP (15 feet, 16 feet) input voltage: 5~18V;
PWM, and BATDRV, and ACDRV (21 feet, 23 feet and 24 feet) output voltage:-0. ３～２０Ｖ；
1~5 feet, 8~10 feet, 13~14 feet and 18~19 feet of input or output voltage:-0. ３～８Ｖ；
Working ambient temperature (TA):-40~85℃.
3 circuit and how it works
Bq24700 notebook PC charge management application in electric circuit as shown in Figure 2. On the input side of the circuit connect AC wall adapter, output port connected notebook PC systems. Q1 (p-Channel MOSFET) fully electric switch, Q2 for adapter selection switch Q3 for battery selector switch.
3. 1 circuit works
ａ． Dynamic power management (DPM)
Battery charge current IBAT adapter difference between the current system and IADPT current ISYS, IBAT=IADPT-ISYS. If the IBAT of ISYS and adapter of current limit is exceeded, through the DPM function reduces the battery charging current, so that the entire input current consumption remains within the limited capacity of the wall adapter. As the system decrease in current, charge current will increase accordingly, so that the battery charging time down to a minimum.
DPM regulation through the battery charging voltage and charging current and adapter, three control loop so that the charging current to PWM controller. If the programmed threshold with any one of the three user reach, control loop PWM controller commands accordingly reduce the duty cycle to reduce battery charging current.
ｂ． AC adapter detection
IC ACDET feet (1 foot) via an external resistor divider to detect the presence of AC adapter and power loss. Application circuit, because R1 is connected to the blocking diode D1 as anode, so VADPT ≥ requires adapter voltage 18V (when you VADPT<18V, R1 is connected to the D1 cathode). When the voltage is lower than the internal comparison on ACDET feet 1. 2V reference level, IC will enter the sleep state, PWM control stop, Q2 shutdown, Q3 leads to choose battery power as the system. Systems (load) voltage can monitor VS resistance voltage divider on the feet, so that in Q2 when a short circuit occurs and the adapter power still exists, power on the system to provide protection.
ｃ． Battery charging operations
Bq24700/1 fixed frequency PWM controller provides closed-loop control can be used to charge the battery. VBAT battery voltage, battery charging current IBAT IADPT and adapter charging current control of three parameters, either by the DAC or the keyboard IC 5V reference voltage of external programming resistor divider, also could use the internal reference voltage (1. 25V) program. Adapter and battery charging currents with low value resistor R5 and R6 respectively to detect, and feedback to Panasonic Lumix DMC-TS2 Battery Charger the IC inside the transconductance (GM) on your amplifier. Battery voltage divider detection through R7 and R9, and will detect the signal back into third GM in IC amplifier.
(1) the battery charging voltage setting
Battery charge adjusting VBAT voltage can be composed of resistance divider and R7 and R9 with IC BATP (13) feet back into battery error amplifier, as long as the BATSET (9) on the foot of VBATSET voltage is greater than 0. Reference voltage of 25V, battery charging voltage can be set to:
ＶＢＡＴ＝[(Ｒ７＋Ｒ９)／Ｒ９]•ＶＢＡＴＳＥＴ
(2) the battery charging current setting
IBAT battery charging current can be used by IC pin SRSET (5) on the voltage-sensing resistor R6 VSRSET and determine, as follows:
ＩＢＡＴ＝ＶＳＲＳＥＴ／(２５Ｒ６)
Type on, VSRSET the maximum value is 2. ５Ｖ。 The voltage can be passed from VREF (5V) resistor divider, and DAC can also be done from the keyboard controller available.
(3) adapter current setting
ACSET IADPT by IC foot adapter current (6) voltages on the adapter to determine current sensing resistors R5 and VACSET:
ＩＡＤＤＰＴ＝ＶＡＣＳＥＴ（２５Ｒ５）
ｄ． Battery drain detection
Battery level can be imposed through the resistor voltage divider to IC pin BATDEP (4) on the voltage setting. When excessive battery discharge time, ALARM (19) foot will send alarm signal and output a high level, and they do not care about power supply selection.
When the battery voltage falls below when you have run out of level of 80%, are considered battery deep discharge. When the battery is exhausted, on the bq24700 will still remain JVC GR-D796 Battery Charger in power has been selected. However, bq24701 is when the battery runs out, automatically switches to the adapter power supply. Table 2 lists the options available for both devices.
Table 2 bq24700/01 selection
3. 2 major component selection
ａ． MOSFET selection
Selection depends on the gate-source voltage of the MOSFET, the input voltage and the input current. P-Channel MOSFET gate-source voltage of at least 20V, BVDSS Breakdown voltage ≈ VIN+1V. The average input current is calculated as follows:
ＩＩＮ(ａｖｇ)＝[（ＶＯＩＯ）×１． ２[／ＶＩＮ
Current effective values determined by the following:
ＩＩＮ(ＲＭＳ)＝ＩＩＮ(ａｖｇ)(１／Ｄ)１／２
Type, d is the duty cycle.
ｂ． Schottky Diode D1 selection
When you select a Schottky Diode D1, require D1 must be able to withstand the input voltage VIN.
ｃ． Inductor selection
To prevent the current slope is too steep resulting in excessive ripple inductor in the circuit of inductance values cannot be too small, recommended-press Select:
Ｌ＝[(ＶＩＮ－ＶＢＡＴ)ＶＢＡＴ]／０． ２ｆｓＩＦＳＶＩＮ
Complete easy to use power management and conversion IC
Power management solutions
Power management is 1 of today's hot technologies. Power management including power control, Nikon Coolpix S500 Battery Charger sequencing, tolerance, etc. Power management requires a new approach. Figure 2 shows the output of Zilker Labs company programme.
Table 1-power supply module BoM comparison
Power module BoM Zilker solutions and comparison of simulation programmes are provided in table 1.
Can be seen from table 1, Zilker programme advantages are: larger current power, fewer components, more performance.
Power management diagram
Zilker Labs Digital-DCTM technology is characterized by:
Accurate control of power conversion;
Integrated power management;
Easy to use, does not require programming;
Small footprint, fewer discrete components;
Ling design;
High efficiency;
Wide working range.
Figure 2 a new method of power management
Power management IC ZL2005
Zilker Panasonic Lumix DMC-FX33 Battery Charger Labs introduces power management IC ZL2005, functions box diagram in Figure 3. ZL2005 characteristics:
Efficient synchronous buck;
Integrated MOSFET drives;
Oblique wave precision delay timing;
Voltage/current/temperature control;
Sequencing;
Tracking;
Tolerance function;
SMBusTM/PMBusTM compatible;
Lead lap;
Efficiency optimization;
Nonlinear response;
Single-supply operation;
Online design and simulation tools.
The ZL2005 function block diagram
ZL2005 typical application circuit is shown in Figure 4.
ZL2005 improved transient response of a nonlinear loop shown in Figure 5. ZL2005 efficiency performance as shown in Figure 5.
ZL2005 typical application circuit
ZL2005 efficiency performance
Closing remarks
Zilker power management programme has is good of performance (high speed conversion, efficient, 1% output precision, fast blink State response), flexible and easy using (introduction feet take received, resistance device set or by SMBus set, does not JVC AA-V16 Battery Charger needs programming, 1 a devices applies many application, online design tools simplified circuit design) and more small of size (less of Division components, elimination power management chip). Zilker programme is a complete and easy power management solutions
LM1875 amplifier board design examples
Circuit
LM1875 amplifier board controlled by a high and low, respectively, attenuated tone control circuit and the LM1875 amplifier and power supply circuit has three major components, the pitch part is the high and low attenuation control tone circuit, which the R02, R03, C02, C01, W02 composed of bass control circuit; C03, C04, W03 composed of treble control circuit; C05 R04 for the isolation resistor, the W01 for the volume control, adjust the volume level of the amplifier, to prevent after-class LM1875 DC blocking capacitor pre-tone circuit. The amplifier circuit using the LM1875, 1875, R08, R09, C066 and other components, circuit magnification ratio of the decision by R08 and Nikon EN-EL11 Battery Charger R09, C06 for 4 feet of stable LM1875 DC drift of the zero potential, but the sound quality the impact of C07, the role of R10 is to prevent the amplifier to produce low-frequency self-excited. Load impedance of the amplifier 4 → 16Ω.
In order to ensure the sound quality of the amplifier board, power transformer, output power shall not be less than 80W, the output voltage of 2 * 25V filter capacitor the two 2200UF/25V electrolytic capacitor in parallel, shared four 2200UF/25V capacitance of the positive and negative power supply, two 104 ceramic capacitor is the high-frequency filter capacitor, the sound quality of the amplifier.
Assembly and debugging:
Tools ready: 20W soldering iron one, the best is the thermostat, if needed contact with the station; a multimeter Panasonic PV-GS35 Battery Charger needle nose pliers a screwdriver, solder wire, and pine fragrance several.
To welding: welding the various components, the first welding smaller, required before welding LM1875 LM1875 using screws on the heatsink, otherwise very difficult to play in the final installed heat sink screws into. The LM1875 and heatsink contact part to be coated with a small amount of thermal grease to facilitate heat dissipation. Must pay attention to the quality of welding, welding for beginners, can be used circuit board to practice several times, and then formally welding.
Debugging debugging particularly simple: this amplifier boards, circuit plate welding of electronic components, to double-check the circuit board with or without welding the wrong place, with particular attention to the polarity of the electronic parts such as electrolytic capacitors, bridge rectifier heap, once the welding anti that burned down the components of risk, please pay special attention. Connected to the transformer, the amplifier output to not pick the speaker, but then a multimeter, preferably digital display multimeter in DC 2V file. Amplifier board the power to observe the multimeter readings Under normal circumstances, the reading should be less than 30mV, or should be turned off immediately check the circuit board. If the meter readings within the normal range, it indicates that the amplifier board JVC GR-D375U Battery Charger function was normal, and finally connected to the speakers, input music signal, power-on test machine, rotate the volume potentiometer, and the volume size should change, rotary bass and treble knobs, speakers the tone has changed.
Motor vehicles travel essential emergency tools overview
Vehicles increasingly become an everyday means of transport, go out the road will inevitably encounter car problems when, for example, broke, running out of battery power, had a flat tire, and so on. Owners is needed at this time there is a well-equipped practical emergency kit. So what this emergency kit needs tools?
Car emergency tool package includes: folding reflective warning flags, nylon, tow rope, taking the fire Nikon Coolpix P300 Battery Charger line, inverter, cotton work gloves, multifunctional flashlight, automotive fuses, disassembly free repair tire tools, waterproof tape and insulation tape, fire extinguishers, 11 essential tools such as air compressor.
, Foldable reflective warning signs
This foldable reflective warning flag is extremely practical, in your car when problems need a stop check, 50 meters away, put it in the rear of the car, reminding passers-by slowdown ahead. At the same time, not when warning signs that can be folded inside the car will not take up much space.
Second, nylon tow rope
To prepare a dragging at least 3 tonne truck trailer, so that when the car broke down to easily tow.
Three, taking over FireWire
When the car radio does not boot, which can be launched from a vehicle battery. Bold battery starting Panasonic Lumix DMC-FS18 Battery Charger line, the maximum current is 200AMP, for displacement to 2500cc gasoline engines or emissions less than 2000cc diesel engines between battery use.
Use process to note:
Two cars cannot have any contacts in two-car electronic systems must have the same voltage.
If the batteries freeze, you cannot use the battery to start taking fire.
Before connection, two engines, car stereo, air conditioning will need to be turned off.
Connection procedures are as follows:
First line the red wires and pliers will be started in "saved cart" above the Red battery cathode.
Red wire pliers and then plug the other end in the "rescue" above the Red battery cathode.
Wire clamp in black "was put" on black anode battery.
Then wire pliers black in "rescue" on black anode battery.
Start the "rescue" engine, and then start "being saved" engine. If was put cars still will not boot, it is necessary to check whether the metal contact with some bad.
When you finish after starting the engine remains to be removed in order to start taking fire, failure to do so may cause short circuits.
Removing wire procedures are as follows:
First "saved cart" black wires removed.
"Rescue" the black wires removed.
And "rescue" the red wires removed.
Finally the "rescued" the red wires removed.
Four-, in-car power inverter
Car inverter is able to convert the 12V DC and AC 220V AC with the same, for use by General Electric, is a convenient power converters for cars.
Car inverter power supply in mobile use in DC to AC converter, will bring to your life a lot easier, is a standing offer of motor vehicle electronic equipment supplies. Via the car cigarette lighter output inverter can be a 20W or 40W until 150W, 80W and 120W power specifications. No matter how big the power inverter received through a connector on the battery.
To note here is that buying car inverter power supply, not corruption, mainly according to their own electrical appliances use conditions to choose. If it is only to charge the mobile JVC AA-VF8 Battery Charger phones, digital cameras, digital cameras, and occasionally in the car with a laptop, select power inverter for 150W power supply can be done; but if owners need regular out, or lovers of self-driving tour, over 200W of power inverter is the wise choice.
Samsung VP-DC171Wi digital camera DVD experience
Samsung unveiled a brand new DVD CD-DV--VP-DC171Wi, the product is aimed at home users and Samsung TL225 Battery Charger compatible with most common DVD disc formats currently on the market, including DVD-R/DVD+R (double)/DVD-RW/DVD+RW, greatly extended its recording time. In LP mode, the maximum recording time of up to 120 minutes.
30mm Schneider lens--a clear image of guarantee
Samsung VP-DC171Wi 1/6 "CCD, has more than 800,000 effective pixels, 30mm lens from Schneider company top lens manufacturers in the world with the help of, which take effect very well enough to meet the needs of home users. Its up to 34 times times Nikon Coolpix S230 Battery Charger optical zoom capability, complemented by 1200 times digital zoom, is enough to let the user captured clear images of distal.
Filmed in the actual tests, we found that the Samsung VP-DC171Wi Schneider lens does not live up to its reputation, especially when shooting outdoor landscape, color reproduction was accurate, and the color is very bright.
16:9 wide LCD--makes shooting more comfortable
Though DV is equipped with the viewfinder, but most people are just as we like to use the LCD to Panasonic Lumix DMC-LX5 Battery Charger watch the shooting scene. Therefore, DV screen sizes and viewing, also filmed in a large extent, affected the ease and effectiveness.
Samsung VP-DC171Wi has a 2.7-inch, 112,000-pixel LCD screen, and uses a 16:9 screen size. This not only enables us to shoot widescreen LCD to see more content (approximately one-third than the traditional 4:3-screen), and because of its conformity with the human eye's Visual, hence better playback effect.
We are pleased that Samsung DV was used in the past for the first time should only be used for large-screen plasma television screens of beautiful light technology (FilterBright). Based on test results show that even in April in the beautiful spring, we can in the case of JVC GY-HD100U Battery Charger outdoor light is almost straight, easily see what is displayed on the LCD. Although the effect is slightly affected, but color loss and it is unlikely, without affecting the shooting.
Use the camera for the first time, images shot in the top ten questions (top)
When we were in everyday use of digital cameras, and often come from a variety of problems, so much so that at the time of found a fine view cannot be photographed in a timely manner, allowing you to not very upset. If you understand the following ten frequently asked questions, you will not miss the beautiful scenery.
1, how to choose a digital video camera viewfinder method?
Digital video camera viewfinder electronic viewfinder and LCD viewfinder can be divided into two ways. Maximize the benefits of LCD viewfinder is easy and intuitive, the drawback was displayed under strong light is too weak, and power consumption is very large, continuous action camera time significantly shorter. In consumer cameras, LCD has become the popular choice for consumers, but more practical or Nikon D5000 Battery Charger electronic viewfinder, this scene are not only cheaper, use power-saving, and can use under any ambient light. While the viewfinder screen angle and color effects and the end result is not all the same, but after some time soon get used to.
2, how to prevent digital camera jitter?
These were produced in order to prevent jitter of manpower. When we shoot, hand shaking is inevitable, and therefore can cause image blur. Most cameras today are anti-shake function, its principle is to use the extra pixel anti-shake purposes. There are a few models use optical anti-shake, anti-shake it all is a mechanical, better stability than electronic anti-shake, but this is not to say that, with this feature made the clear without shaking the image of a, in actual use, the anti-shake function is used, the body or arm of a larger movement will continue to be unstable picture. Sometimes still have to support shooting with tripod, camera tripod if interface also can facilitate some prefer traveling friend Autodyne alone.
3, how to avoid taking positions there is no stability problems?
Many DV beginners take out of the screen are not stable, it is line of sight cannot be set, often feel dizzy. Relative levels of fibrillation, fibrillation more unacceptable in the vertical direction, the best approach is to use a tripod to avoid flutter, without tripod do? Use of the following methods:
When shooting with two hands holding the fuselage. First, hold the camera firmly with both hands and arms close to both sides of the chest, and then move the camera to a little a little higher than chest position. Some cameras use an arm can hold up, but you'd be right arm close to the right ribs, then gently hold the camera with the left hand. Panasonic Lumix DMC-FZ18 Battery Charger That could reduce the jitter, for shooting stability. The second method is more efficient, that is, as far as possible avoid using long focal length and use a wide angle lens. Because smaller angle of longer focal length, slightly shaking screen shaking violently, and wide angle lens angle is large, even if moving is not easy to detect the more serious.
4, use manual focus under what conditions?
Automatic focusing system for the following objectives or in the following shooting conditions, the automatic focus devices often happens wrong judgment if the difficulty in auto-focus, you need to use manual focus. As away from screen center of scenery cannot obtained correctly of focus; by shooting of objects-end away from camera is near, another end away from was is far; shooting in fences, and network, and into row of tree or post Hou of main Shi, automatically focus also difficult to worked, as Figure 1; shooting surface has gloss, and light reflection too strong or around too lit of target property; shooting fast movement objects of focus more difficult; in moved objects behind of target property; in rain, and snow or ground has water Shi, automatically focus system may cannot correctly focused.
5, how to obtain a smooth rocking lens?
Holidays are often taken out of hand, it should be noted that the basic posture is: at the outset to separate two feet stand about 50 centimeters, toes slightly outward into eight fonts, to rock the waist. Panning action can thus be more smoothly. Whether it is panning up and down or left and right panning, smooth smooth actions should be done, keeps the screen smooth, no pauses in the Middle, but also must pay particular attention to Nikon Coolpix S6100 Battery Charger fast and slow. Be careful not to move too much camera, nor in the case of there is no need to move the lens. Panning of start and end points must grasp was right on the nose, skill score-inch. But also to avoid shake shake, such as watering the flowers. Panning not panning back in the past, but to do a panoramic shot of the left and right or up and down.
6, overexposed or underexposed do?
Typically in the first exposure there is a strong light source or contrast too strongly appears bright exposure of part of the right, while others were underexposed. In such cases the best adjusted composition, reduce the proportion of the too bright in the screen. And to switch to manual aperture, in which to show the character or scene to adjust aperture, correct exposure.
The second is insufficient light, objects do not have sufficient illumination, image dark, depth of field shallow. To get the best exposure, you must maintain sufficient illumination. In order to address the problem, of course, now camera has been added brightness gain function: at the time of filming, when the Aperture open to the largest, the camera also detect when insufficient light, will launch this feature, upgrade to electronic brightness of the screen. However, shot in this State tend to be lower quality, and depth of field shallow is also a problem. When shooting in Dim conditions, and may want to increase the lighting or the use of video-lights.
The third is when shooting from a high brightness when an object is transferred to the shadows, the exposure will transform notable. You can manually control exposure, or separately from the contrast of two objects, that is, made first high brightness of the object, pauses, and Panasonic DMC-TZ5 Battery Charger then turn it over to the shadows, until after the automatic exposure system to adjust the aperture and then to shoot.
Civilian King of high definition HDV Sony FX7E parameters
Recently, Sony has released a new generation of HD camcorders product HDR-FX7E, which is Sony's first 3CMOS sensor HD cameras. Sony said, again enrich the product line of Sony HD cameras: from household consumer HC3E HD cameras, high-definition DVD camera UX1E, hard disk-SR1E, FX7E for professional user level.
Sony FX7E
3CMOS technology for Sony's next-generation CMOS sensor contains 3 separate, each sensor control a primary colors – red, green, and blue (RGB), can generate up to 1920x1080 pixel high definition signals. Sony 3CMOS technology and enhanced imaging processor capable of Sony NP-FM30 Battery Charger achieving both high image resolution, recreate the camera a more sensitive and more true color.
Sony FX7E is equipped with 20 times optical zoom, move to manipulate with the lens, you can be sure that image scaling 20 times when image quality is not subject to any influence. In addition, built-in optical jitter-proof system to ensure that in the case of long distance and other easy hand shake reduction image dithering to stabilise the shot Super anti-shake shot can also be due to the effect of jitter is reduced to minimum. Karl • Zeiss Vario-Sonnar t * lens with multi-layer coating technology, the ability to color reproduction of the very real, and ultra low dispersion lens, can effectively reduce color distortion caused by light refraction and dispersion phenomena.
Sony FX7E zoom and focus band is separate from, and enables you to let you enjoy shooting. HDR-FX7E manual function button setting behind the aperture, the camera is very smooth. In addition, HDR-FX7E has some other manual adjustment, according to JVC GR-D370U Battery Charger the pictures can mediate such as shutter speed, white balance and brightness gain value.
Sony FX7E using HDV high definition mode, you can set the "HDV1080i" standard image storage on MiniDV tape. This video format there are 1080 effective scanning lines than conventional DV format standard twice, has more than doubled, in high standard 1080i video, picture clarity about 3.7 times times the normal standard DV cameras. HDR-FX7E compatible with SD/HD formats, it records the context is able to playback in SD/HD cameras.
3.5 inch Sony FX7E crystal color display setting in the camera's left side, you can monitor 16:9, large screen, clear, beautiful images. Resolution up to about 211,000 pixels, you can display HD images, let you shoot while watching the image quality. This displays not only Rotary 90o, you can also to 270o radius of rotation. When you are in when shooting images of very high or low position, it also lets you easily see the of images.
HDMI specification can be images, audio and control signals through a wire transfer, reducing the Nikon D80 Battery Charger number of terminals needed for data transmission cables. HDMI high definition uncompressed digital video and multi-channel audio input/output interfaces. HDMI is currently a high-definition television and high definition consumer electronics devices, standard formats such as DVD players and recorders.
Main specifications of the Sony FX7E
CMOS total pixels: approximately 1.12 million pixels
Static effective pixels: approximately 1.03 million pixels
Dynamic effective pixels: approximately 1.03 million pixels
Secretary Varioreg;-SonnarT* kaercai lens (filter diameter: 62 mm)
Ultra low dispersion lens
HD 1080i and DV recording
20 times optical zoom
Optical anti-shake
Manual zoom/focus band
Manual gain/shutter speed and white balance
Digital extension (1.5X)
2 independent ND filters
0.54-inch 250,000 pixel viewfinder
210,000 pixels Crystal 3.5 inch color screen
Dual recording functionality (dynamic and static image while recording)
Smooth slow shooting performance (6 seconds)
Can be set to Panasonic DMW-BCF10 Battery Charger function button
Zebra pattern display
Histogram display
Playback Zoom
HDMI interface
Compatible with Memory Stick Duo
Intelligent lithium-ion batteries, repeat charging
Cold-shoe
Dimensions (WxHxD): 145 x 156 x 322mm
Weight (without batteries): 1.4 kg.
28mm wide practical application
Previous DC lens 35 mm equivalent focal length most of them started for the love of friends is really wide-angle effect is not quite right. Unless it can be connected with external wide-angle lens, otherwise everyone would just accept this fact. Since last year, built-in 28 mm wide-angle lens of DC began to rise, to 28 mm wide-angle lens this year, almost all of JVC GR-DV700 Battery Charger Prosumer-level DC has become a standard feature. DC short focal length, and games are played on more than several in this issue DCFever.com on the Canon PowerShot S70 is teaching, we talk about the exhaustion of the 28 mm lens method
Separate the subject and background
We all know that Zoom lens to wide angle end, the picture is also in the size of the smaller. If you want to photograph in a large wide-angle lens will be the main point, we have approached the main point. Because the shooting distance near the main sense of perspective and background becomes more intense, to say the distance between the subject and the background seems farther than the naked eye. The more wide-angle lens, the more obvious effect of this perspective.
We understand this feature, you can use wide-angle lens to shoot pictures with a difference. For example, in a small room, crowded street portraits, photo realistic, we can use wide-angle lens close to the main shoot, shoot out as the distance between subject and background, it seems far more than the naked eye, the subject can be confusing background from exposed.
The principal pulled out from the background, does not necessarily need a large aperture, long focal length caused by the shallow depth of field, but also more difficult to get a digital camera, clear, shallow depth of field, wide-angle lens close-up shots is another good feasible solution .
DC's long focal length with an ordinary shot, the subject and background is easy to squeeze together.
With 28 mm wide-angle shots, the subject and background successfully separated.
Strong sense of space photos
Expression in three-dimensional picture plane, the basic method without lines, shadow and Panasonic DE-A25, DE-A25A, DE-A25B Battery Charger proportion techniques. If we can use 28mm or shorter focal length wide-angle shots, the prospects, the background will be a small perspective effect is more obvious, and the ratio of foreground and background of the size of the eye in the photo looks more exaggerated, that outlook looks more than looks great, the background looks smaller than it looks. In this scale under the influence, you will feel picture looks more sense of space. If you can shoot a low angle or radioactive lines with the help of the photo a sense of space will be more intense.
Shooting with long focal length, the sense of space smaller.
With wide-angle shots, a larger sense of space.
Picture lines can be further strengthened with radioactive sense of space.
For hyperfocal shooting
We take photos or Snap Shot dynamic when they may have this experience, completion of the camera focus, the most exciting moments have been missed. To solve this problem, photography in the film era was the use of ultra-focus-focus approach omit the time, the moment you press the shutter can capture clear images. Ultra Focus is the principle use of depth of field, at a particular focal length, aperture, the camera lens set to the calculated focusing distance (ultra-focus), you can get the most depth of field. Without having to re-focus on the case, specify the distance to infinity in the Scene can be clearly photographed. Hyperfocal formula is this
Can be seen from the above formula, using the shorter focal length, the more fine aperture, focal length over the more obvious effects. Since the actual focal length Bi Feilin digital camera camera is much shorter, so do not use too small aperture over focal length can also get decent results. Use a 28mm equivalent focal wide-angle lens digital camera, Nikon D300 Battery Charger digital camera would be more than obvious super-focus effect. But we should note, the resolution of the formula units lines / mm, does not mean that pixels can be obtained through the following calculation
If the Canon PowerShot S70, for example, CCD resolution of approximately 136.1 lines / mm, if taken in the widest angle and aperture setting of f / 4, then over about 1.16 m focal length. As long as the focus with manual focus function will be set at about one meter location point from 0.58 m to infinity of the subject can clearly capture.
Auto focus mechanism has three kinds of did you know?
On the friends of photography, baby equipment is in the hands of works, how to conduct ranging focus, may spend much thought and effort at the top! In General, the DSLR focusing when shooting works through adjustment of Sony NP-FS11 Battery Charger mutual position of the lens within the lens and the distance of PC components, so that objects can be clearer imaging on PC components, focusing is the screen from fuzzy to clear the process. But you think it only this one, it would be quite wrong!
Focal length and focus
Digital camera lenses taking pictures of how it works is: through the lens of light move apart on a spindle Imaging. This point is known as the focus, focus position that is in the camera location of PC components. Focus to the center distance is called the focal length of the lens, lens focal length is important parameters.
Zoom lens focal length is variable, and focal length of the shortest and the longest focal length ratio, called the zoom lens zoom ratio.
The focus, focal length, schematic diagram
On focus and focus operations
Focus, focus can be understood as seeking, through the moving mirror lens group one or more pieces of the lens to adjust the focus, that can clear image on the PC components. Default is usually the focus of the digital camera JVC GR-D390U Battery Charger
Correct way is to first half press the shutter, digital camera LCD screen or subtle changes in the viewing window, also means that the camera is focusing operations; focus is complete, then press the shutter, you can make sure the image focus clear.
Two types of digital cameras to focus on the focusing screen representation
Three kinds of auto focus mechanism
Digital camera auto focus there are several different forms, namely: active infrared focus, CCD AF (contrast Detection AF method) and the method of phase difference measurement. Following a brief account.
Nikon camera focusing on keys.
1. active infrared focus
This principle of focusing mechanism is: the infrared camera focusing system with ultrasonic infrared beam focusing Panasonic DMC-FS20 Battery Charger system issued or ultrasound is reached when the object is being taken, camera receiver on the reflected infrared light or ultrasound is in focus. Active infrared focus mainly for low-order universal camera auto focus, can be carried out in a low contrast, Dim light focus.
2. CCD AF (contrast detect AF)
By contrast Detection AF is used by most digital cameras focus mode, it works is to increase the focus on regional comparison of brightness, look for regions with the highest brightness contrast and focus locked in that position.
This approach has the advantage that the absorbed object contrast is the larger, can still be completed accurately focus the camera work. CCD AF focus method is more mature, and low cost, so it is widely used. But the disadvantage of this method are: the absorbed object difficult to complete focus at lower contrast. Therefore CCD AF (contrast detect AF) AF performance is under the shimmer environment greatly limit.
3. the phase difference measurement focus
Digital SLR cameras Nikon Coolpix S7 Battery Charger used this method of focus, it is the working principle of AF detection device measured the actual focus away from the correct location of the gap, and then adjust specific principle is more complex. This form the most accurate focus, is used in most digital SLR cameras, and has a high reliability.
FREE Blog at Beeplog.com
Responsible for the content of the member blogs are our members, not the provider, Beepworld GmbH
|
|
|
