# How to control the current of the anti-vibration motor

Update:22 Nov 2021
Summary:Many friends are very interested in how to control the current of the anti-vibration motor. This is indeed a critical an...
Many friends are very interested in how to control the current of the anti-vibration motor. This is indeed a critical and arduous task. In order to facilitate your operation and use and solve your questions, I will introduce some related content to you next. You can read it carefully.If the external inverter bridge of the anti-vibration motor is grounded through the resistor Rs as current sampling. The sampling voltage should be input to the current from pin 9 to pin 15, and the comparator can be detected in this way. At the inverting input of the comparator, a reference voltage of one hundred millivolts can be set, which can be used as a reference for current limit.During the ramp-up period of the anti-vibration motor oscillator, if the current is too large, the comparator should be flipped, and then the Rs flip-flop should be reset to turn off the driver output, so there is another function, which will limit the current increase.During the falling period of the oscillator's sawtooth wave, you can set the trigger again to turn on the driver output. By comparing this periodic current, the current limiting function can be realized. If the allowable current is set to Imax, the sampling resistor can be selected according to the following formula: Rs = 0.1 / Imax, before the pin 9 is input, the current detection error caused by the shock-proof motor current can be avoided by setting the RC low-pass filter.It can be known from mechanics that a circle can be divided into 360°, which is a normal mechanical angle. In electrical engineering, the angle unit used to measure the electromagnetic relationship is called the electrical angle. This angle divides the weekly sinusoidal alternating current into 360° on the abscissa, that is, when the conductor space passes through a pair of magnetic poles, the electromagnetic corresponding Change the electrical angle of 360°°. Therefore, the relationship between the electrical angle and the mechanical angle in the motor is: electrical angle α = number of pole pairs xPx360°. For example, for a two-pole motor, the number of pole pairs p = 1, then the electrical angle is equal to the mechanical angle; for a four-pole motor, p = 2, then the motor has two pairs of magnetic poles on a circle, and the corresponding electrical angle is 2×360° = 720°. and many more.