温差电磁铁是通过温差电流的磁效应来演示温差电现象的。新型温差电磁铁具有结构简单、容易制作、演示效果明显、成本较低的特点。 实验装置主要由CD系列小型变压器铁芯、双回路温差电偶、衔铁三个主要部分组成。CD16×32×65小型电源变压器铁芯在市场有定型产品出售,这种铁芯为马蹄形,是用冷轧硅钢带制成,其极面经磨抛达到_7的光洁度平面。这种铁芯不易保留剩磁。将铁芯中部打孔固定一吊环(图1),衔铁可用6～8mm厚的铁板加工成58mm×32mm的长方形,其中心打孔,攻成M4螺扣,以固定砝码环(图2)。衔铁的上表面经磨床加工达到_7光洁度平面。如加工有困难,也可用同样型号的CD型铁芯替代衔铁。双回路温差电偶,是用铜和 Thermoelectric thermomagnets demonstrate the phenomenon of thermoelectricity through the magnetic effect of thermoelectric currents. The new temperature difference electromagnet has the characteristics of simple structure, easy fabrication, obvious demonstration effect and low cost. The experimental device consists of three major parts: the CD series miniature transformer core, the dual-circuit thermocouple, and the armature. CD16×32×65 miniature power transformer cores are sold in the market. These cores are horseshoe-shaped and are made of cold-rolled silicon steel strips. The pole faces are polished to a surface finish of _7. This core is not easy to retain remanence. The center of the core is punched and fixed with a ring (Figure 1). The armature can be processed into a 58mm x 32mm rectangle with a 6-8mm thick iron plate. The center of the armature is punched and tapped into a M4 screw to fix the weight ring (Figure 2). ). The top surface of the armature is machined to a _7 finish. If the processing is difficult, the same type of CD core can also be used instead of the armature. Dual circuit thermocouples are copper and