【正文】 FH END附錄Ⅲ英文原文及翻譯The Controller of the Domestic Electric WaterHeater1. The perspectives of applianceWaterheater is a kind of domestic electric appliance which can be used in bathroom, wash room and kitchen. The types of waterheater available in the market at present includes: electric waterheater, solar waterheater, gas waterheater. To be specifically in China, the use of solar waterheater is limited by the weather and the scope for use is narrow while gas waterhater is fueled by petrol and gas, the supply of which will be difficult to meet the increasing demands and bad for environment. So the electric waterheater has bee more and more popular among customers. According to statistics from Chinese mercial federation not long ago, the market share of electric waterheater in sales volume and sales revenue has surpassed the gas waterheater which keeps ahead for along time. It is predicted by this federation that driven by the largerscale reconstructing of the electric network in the city and the extensive startup of the housing market in the city, the market for electric waterheater will present the strong growth tendency in the next few years. 2. The Goal for DesignThere are two kinds of electric waterheaters available in the market at present: the continual fluent type and water storage type. Considering the special demand of the moist working conditions on single chip, we adopt the newly promoted MC68HC08 single chip by Motorola to be the control center. With its high resistance to interference, steady working, flash memory and so on, this single chip can satisfy the demand of the electric waterheater with high performance. Also considering the fierce petition in domestic appliances industry, we will realize these functions by using ponents as simple as possible to reduce the cost. We will make full use of the internal and outer functions to enhance the performancetoprice ratio. With few improvements, it can be produced massively with low cost in practice.3. The LZCCI Hardware Design Technology Standards and CharacteristicsThe main function of the controller is to control the temperature. Besides that, it has to realize the following functions:To display the realtime temperature of water, the range is 0~99℃. To set the temperature of water arbitrarily within 20~80℃.Have the function of appointment which enables 24 hour turning on setting willfully.Have LTD to display realtime temperature digitally. When setting, the temperature and the time set will be displayed by flicker and the controller will have instructions of appointment, heat preservation and heating. Able to look over and revise the ti of system. Equipped with remote controller, the control will be easy and simple.Cut the power swiftly when temperature is too high and alarm. When electricity leaks, cut the power swiftly and propose alarming. When the power is cut, the data set can be preserved. The Structure of the SystemThe system consists of two main parts: the main controller of waterheater and the remote controller, realized by two pieces of 68hc908gr8 respectively. The Power Supply and the Clock CircuitThe power circuit consists of the transformation bridge, the rectification bridge, the filter resistance, the pressure sensitive resistance and integration voltagestabilizer circuit MC7812T and MC7805T, which can provide +5V and the +12V power source for the controller. OutsideOSC1 and OSC2, 8 kHz crystal oscillator is connected with the circuit. The KeyboardThe function of controlling and the enactment of parameters are realized by the pressing the keys. The two keys of the system’s main controller plete directly the functions of heating and the inquiring of the water level, using the keyboard severance pattern and PTA2, PTA3 as the input entrance of the pressing. The keyboard of the remote controller is designed into matrix type. The pressing of the keys will initiate the keyboard severance, by scanning from line to line。 the number of the key can be judged and then sent to the register for preservation and the delivering. The main procedure will deal with it in the keyboard procedure after receiving the number of the key. Since there will be vibration at the moment of turning on and off, the design uses software time delay to eliminate the vibration. The Display CircuitConsidering that the working environment is humid, the main controller takes LED Nixie tube to display. It takes the main way of SPI to expand two piece of 74LS164 as the output orifice of the static demonstration of the sevensegment display. When there is no pressing, the main controller will display the current temperature of water and the remote controller will display the current time。 when setting or inquiring, the remote controller and main controller will flash to display the information set or inquired while when stopping pressing, the display will automatically back to normal. The Realtime Temperature of Water and the Circuit of WaterLevel DetectingThe thermistor will transmit the temperature information into the voltage information and then will be input into cpu by the A/D transformation module. After checking, the realtime temperature will be deduced. The circuit of waterlevel detecting consists of the parallel connection of three resistances with different resistance value. The electricity of the electrode is small (only several microamperes), thus the erosion is little which suits the wide range variety of the resistance of water(10K一100K O). When the water of level of certain resistance doesn’t arrive where the resistance is, the resistance will not work。 when the waterlevel arrives, the three resistances are linked into parallel connection. The information of waterlevel can be judged by transforming voltages from different resistances through PTB1 (high, middle, low and burning). The