Description
This is a new product never used still in original box.
Description
The MC433 is a 4-Axis unipolar stepper motor controller that converts step/direction inputs to jumper selectable wave, full or half step 4-phase power control. Each of the four phase coils of a unipolar stepper motor is connected to an IRF540NS Power MOSFET switch. The IRF540 is capable of 8A continuous current load with the ability to peak at 33A. Each phase is pulse width modulated (PWM) to allow operation over a 7 to 35 volt range. PWM adjusts average current delivered to the stepper motor to better match the resistance/inductance of the motor without the need for load resistors. This ensures maximum power is delivered to the motor over a range of load conditions and motor types. PWM parameters are adjusted using three potentiometers – initial on time, chop rate duty cycle and duty cycle slew rate verse step rate. Chop rate is fixed at 12KHz. On time is the amount of time a switch remains on before PWM operation takes over – this allows the current to build to a maximum level as quickly as possible. Duty cycle is the percentage of on-time to off-time at a given chop frequency. Duty cycle is used to set the average current delivered to the motor. Duty cycle slew rate adjusts the duty cycle based on the duration of a step. As the step rate slows down (motor turns slower) the duty cycle is adjusted to deliver less power to the motor thereby maintaining constant current. Each motor can be individually set for wave, full, half step mode or be disabled by setting two jumpers on a four pin header.
A dedicated 8bit 20MHz RISC microprocessor (ATmega168) controls each axis. The microprocessor monitors step/direction inputs, limit switch input and PWM settings to generate the appropriate step sequence (wave, full or half) based on jumper settings. Three potentiometers set PWM operation for all 4 axis. The control processor automatically reduces current to the motor after 1.5 seconds by reducing the duty cycle and turns the motor off after 20 seconds.
The MC433 is controlled via a PC compatible DB25 parallel port interface connector. The Parallel port interface has four Step/Direction inputs, four auxiliary outputs and four limit switch inputs. The four auxiliary outputs are connected to a Relay Adapter connector and an open NPN control connector. Limit switch inputs are connected to four 0.1” pin headers with pull up resistors – pulling the limit switch input to ground deactivates a stepper motor.
An I2C TWI communications port allows an external TWI controller to communicate with each motor control processor individually to set step mode, activate a step, PWM parameters, limit switch handling and turn off conditions.
The MC433 has a 24pin header connector (J18) for attaching an optional G Code control processor. The optional high performance G Code processor supports USB 2.0 protocol.
Software Tools
The MC433 is designed to work with a variety of third party G Code software programs. Step input for each axis requires an active high pulse lasting at least 2useconds – step inputs are edge triggered. A high level on the Direction input will turn the stepper clockwise or counterclockwise depending on how the motor is connected to the drive port. The direction signal is sampled after the step trigger so it must remain stable for at least 10useconds after the step trigger.
Control Processor Reprogramming
The Software in each Motor Control Processor can be user upgraded the next software release using a free desktop programming utility MC433Prog.exe. MC433Prog.exe can be downloaded from the download tab.
Expansion Options
The MC433 has several expansion options: Relay Adapters, Joysticks, DRO and USB Communication Controllers.
Three Relay adapters are available – each controlled by the Auxiliary output lines. A low current DC relay array capable of handling 24VDC at 2A or 120VAC at 0.4A , a high current relay array capable of handling 30VDC at 4A or 120VAC at 2A and a hybrid MOSFET controller that can be configured to control three small stepper motors or operate as 12 independent 2A 30V switches.
