What is a differential pair?
What is a differential pair?
A differential pair of tubes is also called a pair of tubes or a differential pair of tubes.It is an electronic device that encapsulates two transistors with the same performance parameters,it is usually used in audio amplifier or instrument.Only differential amplifier tube is used in the table.The differential pair has two structures, NPN and PNP.Figure shows the internal circuit structure of the differential pair.
How to detect a differential pair of tubes? First,the electrode is divided according to the diagram,and then the ordinary transistor method is used to detect the electrode.When a transistor is damaged,the transistor with the same magnification and penetrating current is replaced.
What is a Darlington tube?
The Darlington tube and the giant power tube are all composite transistors,which have larger current amplification factor and higher impedance characteristics.The ordinary Darlington tube is usually composed of two transistors or a plurality of transistors, without protection circuit,and the power dissipation is below 2W.The internal circuit structure of the ordinary Darlington tube is shown in Figure.The ordinary Darlington tube is the same as the ordinary transistor.According to the internal structure, we know that there are PNP and NPN,mainly used for high-gain amplifier circuit or relay driver circuit.
How to detect Darlington tube?
The detection method is the same as the ordinary tube.However,the starting voltage value of the launching junction is higher than that of the ordinary tube by the digital meter,and the resistance value of the emitter junction is also larger than that of the ordinary tube by the mechanical meter.After measuring the electrode,it is necessary to measure whether there is an amplification capability,for example,if there is no amplification,it will be bad.The method is:put the multimeter in RX10K2 block,NPN type tube,red pen and E,black pen and C.Pinch the base and the collector by hand,and the stylus should swing,indicating magnifying power;the PNP type tube,the red pen and C,the black pen and E,pinch the base and the collector by hand.