子变压器，输入为AC220V，输出为AC12V，功率可达50W。它主要是在高频电子镇流器电路的基础上研制出来的一种变压器电路，其性能稳定，体积小，功率大，因而克服了传统的硅钢片变压器体大、笨重、价高等缺点。-The sub transformer, input AC12V, AC220V, output power up to 50W. It is primarily developed on the basis of high-frequency electronic ballast circuit of a transformer circuit, its stable performance, small size, big power, thus overcoming the traditional silicon steel sheet transformer body is big, bulky, the price of the disadvantages.