How to control the current of DC geared motor

In the process of using a DC geared motor, the current plays a very important role in the operation of the motor. So how do we control the current of the motor during the process we use? Here are a few ways to introduce you.

If the external inverter bridge passes through a resistor Rs grounded as a sample of the current. The sampled voltage should be input to the current from pin 9 to pin 15, and the comparator is detected in this manner. 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 limiting.

During the period when the oscillator sawtooth rises, if the current is too large, flip the comparator at this time, and then reset the Rs flip-flop to turn off the drive output. There is also a function that limits the current to continue to increase. Big.

While the oscillator sawtooth is falling, the trigger can be repositioned to turn on the drive output. By comparing such periodic currents, the current limiting effect is achieved. If the maximum allowable current is set to Imax, the sampling resistor can be selected according to the following formula: Rs = 0.1/Imax, before setting by foot 9 The RC low-pass filter avoids the occurrence of errors in current detection due to commutation spikes.