Anaheim BLD72-1 Features, What Is a Step Motor Driver?, General Description, Bilevel Drive

Features

•Bilevel Driver Operation

•10 Amps per Phase Operating Current (Kick Current)

•7 Amps per Phase Standstill Current

•70 Volt Operation

•Short Circuit Protection

•Open Circuit Protection

•Unipolar Operation

•Motor ON/OFF Input

•Half-Step and Full-Step Operations

•Fault LED

•Detachable Terminal Block

•CE Certified

•Compact and Rugged

•Available in Driver Packs

What Is a Step Motor Driver?

A step motor driver is a device that takes input signals (usually Clock and Direction) and translates this information into phase currents in the motor. Each time the step motor driver receives a pulse, the step motor moves one step. If the driver receives 200 pulses, the motor moves 200 steps. The motor steps at the same frequency as the clock pulses.

FIGURE 1: Step Motor Driver

General Description

The BLD72 is a step motor driver that can drive motors rated from 1 to 7 amps/phase (unipolar rating). It can handle 6 lead and 8 lead motors. This driver features a unipolar bilevel (or dual voltage) drive tech- nique with short and open circuit protection (with a Fault LED). A transformer is required to power up the driver.

Bilevel Drive

The basic function of a motor driver is to provide the rated motor phase current to the motor windings in the shortest possible time. The bilevel driver uses a high voltage to get a rapid rate of current rise in the motor windings in the least amount of time. When reaching the preset trip current, the driver turns off the high voltage and sustains the current from the low voltage supply.

Half-Step/Full-Step

Users have a choice of full-step operation or half-step operation. Full-step operation occurs by energizing two phases at a time, rotating a typical motor 1.8 degrees per step. Half-step operation occurs by alter- nately energizing one, and then two, phases at a time, rotating the motor 0.9 degrees per step. Full-step operation is suggested for applications that specifically require that mode, such as when retrofitting exist- ing full-step systems.

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