中英文翻译一-zx2018c型直流稳压电源及充电器的工作原理-学位论文.doc

One ZX2018C DC power supply and battery charger works1 ProductsThe products and the charger from the power supply composed of two parts; power supply output 3V, 6V DC voltage, radio and other small appliances can be used as an external power supply; charger to 5, 7, rechargeable battery for constant current charge. 2 features and main parametersDC power supply; input voltage; AC 220V; output voltage; DC 3V, 6V; maximum output current: 500ma. Battery Charger: left channel (E1, E2) charging current 50-60ma (normal charge); right channel (E3, E4) 110-130 charge current (fast charge), two channels can be used simultaneously, each can be charged 5 or 7, two sections of the battery. Power supply and battery charger can be used simultaneously, as long as the two currents and no more than 500ma. 3 Board composition and working principleDescription: The name of the board are: circuit board, PCB, aluminum plates, high frequency board, PCB, ultra-thin circuit boards, ultra-thin circuit boards, printing (copper engraving technology) circuit boards. Mini of the circuit board, visualization, for a fixed volume and optimize the circuit layout plays an important role with the electrical. Single Panel (Single-Sided Boards) We have just mentioned, the basic PCB, components concentrated in one side, wires are concentrated on the other side. Because the lead only in one side, so we call this is called single-sided PCB (Single-sided). Single-panel design lines because there are many strict restrictions (because only one side, the wiring between the AC * and must not be alone around the path), so only until the early use of such a circuit board. Double Sided (Double-Sided Boards) Both sides of this circuit board wiring. But with a wire on the sides, the sides must have the appropriate electrical connections between the Caixing. The circuit between a "bridge" is called the pilot hole (via). Pilot hole in the PCB, the holes filled or coated with metal, it can be connected to the wire with both sides. Because the area of dual-panel twice as big than the single panel, and because routing can be interleaved (might go around to the other side), it is more suitable for use in more complex than the single-sided circuit. Multilayer (Multi-Layer Boards) In order to increase the area for routing, multilayer spend more single-or double-sided wiring board. The number of multilayer films using double-sided, and placed in each cubicleAfter the insulating layer into a layer of sticky jail (press fit).The board are several layers to represent the separate wiring layers, usually layers are even, and includes the outermost two layers. Most of the board are 4 to 8 layers of structure, but technically can be done almost 100 layers of PCB board. Most large-scale use of supercomputers rather multi-layered board, but because these computers have a lot of ordinary computers can be used instead of the cluster, super multi-layer board has gradually being used. Because the PCB layers are in close, generally not easy to see that the actual number, but motherboard if you look closely, and perhaps can be seen.1. Transformer: Using the principle of electromagnetic induction to change the AC voltage of the device, the main component is the primary coil, secondary coil and core (core). In electrical equipment and radio circuits, commonly used for lifting voltage, impedance matching, security isolation. The product of the transformer voltage is 220V-9V.2.Rectifier circuit; to convert DC to AC power circuit. Most of the rectifier circuit by the transformer, rectifier and filter circuit composed of the main. It is in the DC motor speed, the generator excitation regulator, electrolysis, electroplating and other fields are widely used. Rectifier circuit is the role of the AC output voltage step-down circuit into a low one-way alternating current pulse of direct current, which is the process of alternating current rectifier, rectifier diode rectifier circuit composed mainly. After the voltage after the rectifier circuit is not the AC voltage, but a DC voltage and AC voltage with mixed voltage ripple of the customary way, said DC voltage. Power supply circuits are half-wave rectifier circuit rectifier, full wave rectifier bridge rectifier circuit and three, voltage rectifier circuit for rectifying the AC signal the other, for example for LED level indicator circuit, the audio signal rectification. Figure 3-1 rectifier How it works: is a half weeks, on VD2, VD3 and direction of the voltage, VD2, VD3 conduction; of VD1, VD4 reverse voltage, VD1, VD4 end, forming a positive under the negative half-wave rectification wash voltage, in the negative half-cycle When, on the VD1, VD4 plus the forward voltage, VD2, VD4 conduction; of VD2, VD3 reverse voltage, VD2, VD3 closed . Figure 3-2 rectifier output waveform3. Filter circuit: for filtered rectifier output voltage ripple, usually by the reactance components, such as shunt capacitor across the resistor in the load C, or a series with the load inductor L, and by the capacitors, inductors formed from the various Duplex filter circuit. Minimize the ripple filter circuit DC voltage in the AC component, to retain its current composition, the output voltage ripple factor decreases, the waveform becomes more smooth Figure 3-3 filter circuitHow it works: When the change of current flowing through the inductor, the inductor coil by the induced electromotive force to stop the current changes. When the current through the inductor increases, the inductance self-inductance of the coil emf and current in the opposite direction, to prevent the increase in current, while part of the electrical energy into magnetic energy stored in the inductor into; when the current through the inductor coil is reduced, Self-inductance emf and current in the same direction to prevent the current decreases, while the release of stored energy to compensate for the current decrease. Therefore, filtered by the inductor, not only the pulse of load current and voltage decreases, the waveform becomes smooth, and the rectifier diode conduction angle increases.In the case of constant inductance coil, the smaller the load resistance, the smaller the output voltage of the AC component. Only in RL>> L time to get better filtering effect. L bigger, better filtering effect.In addition, the role of the filter inductance electromotive force, can make the diode conduction angle close to , the impact of reducing the diode current, smoothing the flow of current through the diode, thereby extending the life of the rectifier diodes.Let C1, C2, UC1 = UC2 = 0, UC2: I (C1 charge, RL regulator circuit); ab segments: C1 charge, RL regulator circuit; b Section: UL peak. bc Section: U2 decline. C Section: U2> UC, Vd only. RL charged only by the UC Figure 3-4 filter circuit output waveform4. Regulator circuit: the role of circuit adjustments to the output voltage is called regulation. The input voltage, load, ambient temperature, circuit parameters such changes can maintain a constant output voltage of the circuit. This circuit can provide stable DC power, is widely used in various electronic devices. Components for the adjustment of its structure, reference voltage circuit, the circuit of the sample, compared amplifier. Today's society people are enjoying the great convenience brought by electronic devices, but any electronic device has a common circuit - the power circuit. Large supercomputers to small pocket calculator, all electronic devices must support the power circuit to work properly. Of course, the style of these power circuits, complexity vary widely. Supercomputer power circuit itself is a complex power system. Through this power system, supercomputers are able to get the various parts of steady, consistent power supply complex specifications. Pocket calculator is more than a simple battery power circuit. But you can not underestimate the battery power circuit to compare the new circuit is fully equipped with battery power to remind, power protection and other advanced features. Can be said that the power circuit is the basis for all electronic equipment, there would be no power supply circuit such a wide variety of electronic equipment.Because the characteristics of electronic technology, electronic equipment required for power supply circuit is able to provide sustained and stable to meet the load requirements of electricity, and usually require to provide a stable DC power. Can provide such a stable DC power supply is the DC power supply. DC power supply in power supply technology plays a very important position. In addition, many electronics enthusiasts novice first encounter is to solve the power problem, otherwise the circuit does not work, electronic production can not learn to speak of. To this end, Pecker's Home opened up a special technical feature of this DC power supply, hoping to novice electronics enthusiast some help. Enthusiasts can also supply technology as a common reference for daily learning, making the reference Figure 3-5 voltage regulatorRegulator circuit components: 1.VT1, VT2 composite pip 2.R3, LED2 voltage regulator3.R2, LED1 current protection4.VT3 discharger5.R4, R5, R6 sampling circuitVoltage regulator works: When the input U2 rise, leading to V drop in voltage UL, Ub3 rise, Ubc3 rise, Ub increased; Ube3 = Ub3-Ue3UB1 rose Uce , Ub1 IR1 Tc1 Ue , Ic = Ib1 Uo = U2-Uce, U2 <uce5. charging circuit: the charging circuit is divided into ordinary charge, fast charge of two parts. If the distinction between an ordinary charge or fast charge as long as the resistance to stop watching, because the time when U = 9V, I = U / R, R7> R9, for fast charging. Figure 3-6 Charging Circuit Figure 3-7 Schematic principleTwo weldingWelding 2.1 Introduction Any electronic products, from several parts constitute the rectifier to the thousands of component parts of the computer system, are composed of electronic components and functions of the device structure, according to circuit theory, with a certain method of connection from the process. Although a variety of connection methods (for example, wrap, crimping, bonding, etc.), but the most widely used method is soldering. Welding process, the workpiece and the solder melts to form molten region, solidification cooling bath after the formation of a connection between the materials. This process, pressure is also usually required. Welding a variety of energy sources, including gas flame, electric arc, laser, electron beam, friction, and ultrasonic. Before the late 19th century, the only welding process was followed for hundreds of years the blacksmith forging metal welding. The earliest modern welding technology in the 19th century, first arc and oxygen gas welding, resistance welding appeared later. The early 20th century, with the First and Second World war, the military equipment needs of cheap and reliable connection method greatly, so promoting the development of welding technology. Today, with the welding robot applications in a wide range of industrial applications, were still in-depth study of the nature of welding, to continue to develop new welding methods to further improve the welding quality. Circuit boards, circuit board, PCB board, pcb welding technology development process in recent years the electronics industry, you can notice a very obvious trend is the reflow technology. In principle, the traditional plug pieces can also be used reflow process, which is commonly referred to as through-hole reflow soldering. The advantage is likely to be completed at the same time, all the joints, so that production costs to a minimum. However, it limits the temperature-sensitive components of the application of reflow, either plug in pieces or SMD. And then people turn select welding. Most applications can be used in the selection after reflow soldering. This will become an economic and effective completion of the remaining parts of the welding plug, but also fully compatible with lead-free future. Coating process in the selective soldering flux, the flux coating process plays an important role. Welding the end of the heating and welding, flux activity should be sufficient to prevent the bridge and prevent the generation of oxidative PCB. Spray flux from the X / Y PCB manipulator carrying the nozzle through the top of the flux, flux spraying position to be welded to the PCB. Flux with a single spray nozzle, micro jet, simultaneous multi-point / graphics spray a variety of ways. Peak reflow process after the election of microwave welding, the most important thing is accurate spray flux. Will not stain porous solder jet outside the region. Point of minimum flux point of micro-spray graphics diameter greater than 2mm, so the spray deposition flux on the PCB position accuracy is ± 0.5mm, to ensure cover is always in flux above the welded parts, spray welding dose of tolerance provided by the supplier, technical specifications flux should be required to use it is generally recommended 100% secure tolerance. 1. Manual welding tools; electric iron, ferrochrome frame2. Soldering conditions, in order to improve the welding quality, we must be careful to soldering conditions. 3. By welding pieces must have weldability. 4. By welding the metal surface should be kept clean. 5. Using the appropriate flux. 6. With the proper welding temperature. 7. With a suitable welding time. 2.2 SMT (Surface Mounted Technology) SMT is Surface Mount Technology (SMT), is the electronic assembly industry, the most popular form of technology and processes. Its characteristics is the high density assembly, electronics, small size, light weight, size and weight of chip components only the traditional plug-in component of the 1 / 10, the general SMT, the electronics volume reduced 40% to 60%, weight reduce 60% 80%, high reliability, anti-vibration capability. Solder joint defect rate is low. Good high frequency characteristics. Reduce electromagnetic and RF interference. Easy to automate and improve production efficiency. Reduce costs by 30% to 50%. Saving materials, energy, equipment, manpower and time.    SMT process: print (or dispensing) -> mount - "(curing) -> reflow soldering -> wash -> testing Printing: Its role is to paste or glue were missing patches to the pad on the PCB for soldering components to prepare. Equipment used for the printing, SMT production line at the front. Dispensing: Now used by most double-sided circuit board patch, when melted down in order to prevent secondary