Multimeter how to judge the piezoelectric ceramic good or bad
Piezoelectric ceramic is a synthetic piezoelectric material. When subjected to external pressure, the two sides will produce an electric charge, the charge is proportional to the pressure, this phenomenon is called the piezoelectric effect. Piezoelectric ceramics have piezoelectric effect, that is, under the action of the external electric field, will produce deformation, so piezoelectric ceramic sheet can be used as a sound generating element.
The use of piezoelectric ceramic piece of piezoelectric effect, available multimeter to determine its good or bad.
Piezoelectric ceramic piece of two poles out of the two wires, and then the ceramic piece of flat to the table, the two leads were connected to the multimeter on the two pens, the multimeter dialled to the minimum current block, and then the pencil eraser head gently press the ceramic piece of the multimeter, if the multimeter pointer swing obviously, the ceramic piece of piezoelectric ceramic piece of the poles out of the two wires, and then the ceramic piece of flat to the table, the two leads were connected to the multimeter two Table pen, the multimeter dial to the minimum current block, and then use the pencil eraser head gently press the ceramic piece, if the multimeter pointer swings significantly, indicating that the ceramic piece is intact, otherwise, indicating that the damage has been done.
intact, otherwise, it means that it has been damaged.
Distinguish the positive and negative poles of the speaker through the multimeter.
Distinguish the positive and negative poles of speakers by multimeter
First of all, the pointer multimeter dial to DC 0 ~ 5mA block, and then the two pens were connected to the speaker to be tested on the two pads. Lightly press the paper cone of the speaker, observe the direction of the multimeter pointer swing, if the pointer positive deflection, the red pen is connected to the speaker negative, black pen is connected to the speaker positive. Conversely, the red pen is connected to the positive pole, the black pen is connected to the negative pole.
First of all, the pointer multimeter dial to DC 0 ~ 5mA block, and then the two pens were connected to the speaker to be tested on the two pads. Lightly press the paper cone of the speaker, observe the direction of the multimeter pointer swing, if the pointer positive deflection, the red pen is connected to the speaker negative, black pen is connected to the speaker positive. On the contrary, the red pen is connected to the positive pole, the black pen is connected to the negative pole.
