电热水器的原理与检修

Principle and Maintenance About the Electric Water Heater

详细分析储水式电热水器的电路原理,以鲁斌牌QZD-1型热水器为例介绍电热水器的电源电路,水位显示电路,防止干烧电路和防止漏电电路。重点介绍水位显示电路和防止干烧电路,水位显示电路主要以IC1(MC4069)反相器为核心,可以检测注水到某一位置;防止干烧电路主要以IC2(LM339)比较器为核心,实现当水箱水位低于2/6位置时断电。最后,就该电热水器可能出现的故障,给出针对故障进行检修的方法,为初学电热水器设计与检修者提供参考。

In this article,the author mainly analyzed circuit of storage-type electric water heater.Furthermore,detailed analysis about the water heater named Lu Bin QZD-1 were introduced,including power circuit,level display circuit,prevention of dry circuit and preventing leakage circuit.Especially,the last two parts of the circuit were very important.IC1（MC4069） comparator is core component of level display circuit,which can detect the position of water in the liner;simultaneously,IC2（LM339） is considered as a key device of prevention of dry circuit,which could cut off the power if the water level is lower than 2/6 location in the water tank.Finally,the author proposed appropriate methods of examination and repairs for possible faults of the storage-type electric water heater,which can provide reference to beginners who learn design and maintenance.