廉价3D打印机一般用这个模块驱动步进电机。

不过，让人困惑的是，这货的电压标识很奇怪。供给他多少电压才算对？

实际上，这货datasheet上有个参考电压。通过这个参考电压，调整输出电流，然后驱动电机。

That driver will work fine,provided you use a proper power supply.

The allegro stepper-drivers arecurrent-limited chopper stepper drivers. As such, you only have to ensure thepower-supply voltage for the driver is > then the rated voltage on thestepper, and you have set the current limit properly.

Basically,chopper-stepper-drivers actually modulate (“chop”) the drive voltageto the stepper in real-time to maintain a fixed coil current.

The ratings for your motorare steady state. Basically, it says that if you apply 2.55V DC, 1.7A of current will flow though the motor coil.

However, the Allegro driversdon’t apply DC, they apply a duty-cycle modulated square wave, which limits theoverall power delivered to the motor.

Functionally, the driver willvary the applied voltage to the stepper to maintain a fixed current (it’s notquite that simple, motor inductance is involved, but it’sa reasonable simplification). As such, as long as you’re not applying more then1.7A of current to the motor, it will work fine.

Basically, the simple versionis the motor ratings are basically constrained by the thermal behaviour of themotor. If you apply too much power, it’ll get hot enough to damage the motor.

With the A4988 driver board youlink, you can vary the motor current by adjusting the tiny pot, which allowsyou to adjust the motor power to whatever you’d like.

If you run the driver off inputDC within it’s operating range, you will be fine.

电压其实无所谓，通过调整Vref，可以轻易的调整电流，达到调整功率的作用。

现在5v可以用8v驱动，然后调整电流，得到整个完整功率。

再无需转换器了。