How is the motor current controlled

Update:14-12-2019
Summary:

Many friends are very interested in how to control the […]

Many friends are very interested in how to control the current of the motor. This is indeed a key and difficult task. In order to facilitate your operation and solve your doubts, I will introduce some related content to you. You can read it carefully. a bit.

If the external inverter bridge passes through a resistor Rs to ground as the current sampling. The sampled voltage should be input to the current from pins 9 to 15, and the comparator detection should be performed in this way. At the inverting input of the comparator, a reference voltage of one hundred millivolts can be set, and this voltage can be used as a reference for current limiting.
During the period when the sawtooth wave of the motor oscillator rises, if the current is too large, the comparator is flipped at this time, and then the Rs trigger is reset to turn off the drive output. In this way, there is a function to limit the current to continue Increase.

During the period when the sawtooth wave of the oscillator drops, the trigger can be reset to turn on the drive output. Through such a comparison of the periodic current, the current limiting effect is achieved. If the allowable current is set to Imax, the sampling resistor can be selected according to the following formula: that is, Rs = 0.1 / Imax. Before the input of pin 9, by setting RC The low-pass filter can avoid current detection errors caused by commutation spikes.