There are many types of diodes, which can be divided into germanium diodes (Ge tubes) and silicon diodes (Si tubes) according to the semiconductor materials used. According to their different uses,
A crystal diode is a p-n junction formed by p-type and n-type semiconductors,
The technical indicators used to indicate the performance and applicability of a diode are called diode parameters.
Reverse current refers to the reverse current flowing through a diode at a specified temperature and maximum reverse voltage.
Touch the red probe of the multimeter to the positive terminal of the diode and the black probe to the negative terminal of the diode. If the pointer is at or near infinity, the tube is qualified.
According to their characteristics, point contact diodes are classified into forward and reverse characteristics as follows
