一、电源和用电器用电器是利用电流工作的电气元件或设备.它能把电能转化为其他形式的能.如电灯、电风扇、电饭煲、电冰箱、电视机、空调器等.在电路中,提供电能的装置就是电源.通常使用的电源有直流和交流电源两种,如手电筒里的干电池和汽车上的蓄电池都是直流电源,而家庭电路的电源是交流电源.直流电源有正、负极,分别用 First, the power and electrical appliances Electrical appliances is the use of current electrical components or equipment that can convert electrical energy into other forms of energy, such as lights, fans, rice cookers, refrigerators, TV sets, air conditioners, etc. In the circuit , The device that provides the electric energy is the power source.The commonly used power source has the direct current and the alternating current power source two kinds, like the dry battery in the flashlight and the automobile battery all is the direct current power source, but the home circuit power is the alternating current source.The direct current power source has positive and negative , Respectively, with