Darlington tube is two triodes connected together, and the polarity only recognizes the front triode. Take two triodes with the same polarity as an example. The collector of the front triode is connected with the collector of the back triode, and the emitter of the front triode is connected with the base of the back triode. The power of the front triode is generally smaller than that of the back triode, and the base of the front triode is the base of the Darlington tube, and the emitter of the back triode is the same as that of the triode. The magnification is the product of the magnifications of the two triodes.Darlington tube is two triodes connected together, and the polarity only recognizes the front triode. Take two triodes with the same polarity as an example. The collector of the front triode is connected with the collector of the back triode, and the emitter of the front triode is connected with the base of the back triode. The power of the front triode is generally smaller than that of the back triode, and the base of the front triode is the base of the Darlington tube, and the emitter of the back triode is the same as that of the triode. The magnification is the product of the magnifications of the two triodes.