How to distinguish diodes and transistors through appearance

How to distinguish diodes and transistors through appearance

A transistor has three legs and a diode has two legs. If it is a half bridge composed of two diodes, there will be corresponding symbol prompts.

Model, Material:

1: Domestic transistors:

The first number represents the number of electrodes, with 2 for diodes and 3 for transistors;

The second letter represents material and polarity, A represents PNP type germanium , B represents NPN type germanium , C represents PNP type silicon , and D represents NPN type silicon ,

The third letter represents the purpose of the transistor, for example, A represents high-frequency high-power transistor, D represents low-frequency high-power transistor, G represents high-frequency low-power transistor, and the following numbers represent the serial number. Please refer to the manual for specific parameters.

2: transistors in Japan:

The first number represents the effective number of electrodes in the device, 0 represents the photosensitive device, 1 represents the diode, 2 represents the transistor, and 3 represents 4 electrodes or 3 PN junctions;

The second digit is fixed as S, the third letter represents material and polarity, A represents PNP type germanium , B represents NPN type germanium , C represents PNP type silicon , and D represents NPN type silicon .

The third part represents the registration number, and the fourth letter represents the improvement number. Specific parameters can be found in the manual.

3: transistors in Europe and America:

The first letter represents the application level, and JAN represents military products; What does not mean is civilian goods.

The second number represents the number of PN junctions.

The third part is fixed as N;

The fourth part represents the registration number; The fifth part represents the sequence, and specific parameters can be found in the manual.