How does the multimeter judge the common terminal of the motor?
How to judge the common terminal of the motor with a multimeter
Use a multimeter to measure the resistance between the three heads respectively. The largest resistance value 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 terminal;
After the common terminal is determined, it is easy to judge the main winding and the auxiliary winding.
Use the multimeter's × 1 ohm resistance gear 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 terminal.
How to judge the head and tail of the motor?
For a motor, if there is no nameplate, and there are no marks on the 6 lead wires of the motor, how to determine the head and tail of the motor?
answer:
First, use the resistance range of the multimeter to distinguish three sets of windings, then adjust the multimeter to the minimum DC voltage range, and connect the two test leads to the two leads of the same winding respectively. Choose one of the remaining two windings, connect a battery (momentary touch), watch the direction of the multimeter pointer swing (remember), change the multimeter to another set of windings, and repeat the above process.
In the two processes, the swing direction of the multimeter pointer is the same, and the same pen (red or black) is connected to the same end of the two windings.
Change the battery to the other winding, and use the same method to determine the lead wire of the third winding.
How to judge the common terminal of the motor
Use the multimeter's × 1 ohm resistance gear 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 terminal.
How to identify the same name end of the motor
First, use the resistance range of the multimeter to distinguish three sets of windings, then adjust the multimeter to the minimum DC voltage range, and connect the two test leads to the two leads of the same winding respectively.
Choose one of the remaining two windings, connect a battery (momentary touch), watch the direction of the multimeter pointer swing (remember), change the multimeter to another set of windings, and repeat the above process.
In the two processes, the swing direction of the multimeter pointer is the same, and the same pen (red or black) is connected to the same end of the two windings.
Change the battery to the other winding, and use the same method to determine the lead wire of the third winding.
How to judge the positive and negative level 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 or terminal.
When the motor rotates clockwise, the lead or terminal of the motor connected to the positive pole of the power supply is the positive pole, and the other one is the negative pole; if it rotates counterclockwise, the lead or terminal of the motor connected to the negative pole of the power supply is the positive pole, and the other one is the negative pole.
The rated voltage of industrial DC motors is generally above 300v DC. It can be used as a rectifier and adjusted 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, and the rest are the same as above.
Note that if it is an excitation motor, the excitation voltage must be connected.
