How does the multimeter judge the common terminal of the motor?
Use a multimeter to measure the resistance between the three heads. The resistance with the largest resistance is the result of the series connection between the main winding and the auxiliary winding. From this, it can be judged that the other head is the common end;
After the common terminal is determined, it is easy to judge the main winding and the secondary winding. The main winding has a small resistance to the common terminal, and the secondary winding has a large resistance to the common terminal.
Use the multimeter's ×1 ohm resistance file to measure the resistance between the three leads in turn. When the resistance is the largest, the lead that is not connected to the test pen is the common end.
How to judge the beginning and end of the motor?
A motor, if there is no nameplate, and there are no marks on the 6 lead wires of the motor, how to judge and find out the beginning and end of the motor?
answer:
First, use the resistance gear of the multimeter to distinguish the three groups of windings, then adjust the multimeter to the minimum DC voltage gear, and connect the two test leads to the two leads of the same winding. Choose one of the remaining two windings, connect a battery (momentary touch), watch the swing direction of the pointer of the multimeter (remember), change the multimeter to another group of windings, and repeat the above process.
In the two processes, if the pointer of the multimeter swings in the same direction, the same test lead (red or black) is connected to the same end of the two windings.
Replace the battery with another winding, and use the same method to determine the lead-out wire of the third winding.
How to judge the common terminal of the motor
Use the multimeter's ×1 ohm resistance file to measure the resistance between the three leads in turn. When the resistance is the largest, the lead that is not connected to the test pen is the common end.
How to identify the end of the motor with the same name
First, use the resistance gear of the multimeter to distinguish the three groups of windings, then adjust the multimeter to the minimum DC voltage gear, and connect the two test leads to the two leads of the same winding.
Choose one of the remaining two windings, connect a battery (momentary touch), watch the swing direction of the pointer of the multimeter (remember), change the multimeter to another group of windings, and repeat the above process.
In the two processes, if the pointer of the multimeter swings in the same direction, the same test lead (red or black) is connected to the same end of the two windings.
Replace the battery with another winding, and use the same method to determine the lead-out wire of the third winding.
How to judge the positive and negative stages of the motor? How to judge the beginning and end with a multimeter?
First, make sure the motor is a DC motor! When the motor with a voltage lower than DC 30v is directly adjusted to the rated value with a DC adjustable power supply, it is connected to the motor lead wire or terminal.
When the motor rotates clockwise, the lead or terminal of the motor connected to the positive pole of the power supply is positive, and the other is negative; if it rotates counterclockwise, the lead or terminal of the motor connected to the negative pole of the power supply is positive, and the other is negative.
Generally, the rated voltage of industrial DC motors is above DC 300v. A rectifier can be used to adjust the voltage to the required voltage through a voltage regulator with similar power. When the motor rotates clockwise, the terminal connected to the positive pole of the power supply is the positive pole of the motor.
Note that if it is an excitation motor, the excitation voltage must be connected.
