Note the use of FET type and variety series FET more, but their circuit test and measurement method is basically the same principle. During transportation and storage of insulated gate field effect transistor TIP122 wholesale, because of its very high input resistance, antistatic poor TIP122 manufacturers, protective element does not exist within the tube, typically three pins shorted its preservation, in order to avoid electrostatic induction strike through the insulation layer, until the test circuit and its reliable connection TIP122, then shorting removed, then measure. Process should be very careful thorough test operation, the slightest mistake, causing floating gate, is likely to cause damage. IRF9540N one, the role of a field effect transistor FET may be used as a variable resistor. 2, the FET can be conveniently used as a constant current source. 3, the FET can be used as an electronic switch. Second, FET test, pin junction type field effect transistor recognition: the gate of the FET corresponds to the base of the transistor, source and drain correspond to the emitter and the collector of the transistor. The multimeter R × 1k file TIP122 transistors, with two leads were measured positive and negative resistance between two pins each. When positive and negative resistance between two pins equally certain, both the number of KΩ, then these two pins for the drain D and source S (interchangeable), and the remaining one pin is the gate G . For four pin junction FET, the other pole is shielded pole. STP65NF06 TIP122 transistor, Jiangsu TIP122, 耀坤 technology provided by Nanjing 耀坤 Technology Limited. Nanjing 耀坤 Ltd. (www.njykkj888.com) strong, credible, in Nanjing, Jiangsu diode industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead Yaokun into the brilliant technology and you work for a better future!