Brushless DC motor controllers

EM-352 Brushless DC-motor Driver with Modbus

Overview

EM-352 is a brushless DC motor driver with hall sensor feedback for precise speed regulation. The unit features an efficient MOSFET power stage and complies with modern EMC requirements. It supports 120° commutation and a true 4-quadrant power stage, enabling regenerative braking. During braking the supply voltage rises and can be controlled with a braking resistor. In battery-powered systems the regenerated energy can be returned to the battery, eliminating the need for a resistor.

Control Features

Digital command inputs: direction, start/stop, disable, and speed-2 activation
Analog inputs for speed and current control
Modbus RS-485 communication for external control and parameter adjustment
PNP fault output for status indication
Configurable I/O functions via parameters
Protections: overvoltage, undervoltage, and overtemperature (indicated by on-board fault LED)
Current-limit reset via reset input, reset timer, or by setting analog speed command to 0

Open- and Closed-Loop Speed Control

Open loop (direct control): Motor voltage is proportional to the control voltage, like a standard DC motor.
Closed loop: Hall feedback provides accurate speed regulation.

Start and stop ramps operate in both modes. Speed range, closed-loop RPM range, and ramp times are parameter adjustable. Filtered analog inputs also allow the use of a PWM signal for speed and current control.

Configuration and Monitoring

Settings can be configured digitally with the EM-236 interface unit or the Emen-Tool Lite PC software together with the EM-328 adapter cable. Parameters are stored in non-volatile memory. The interface enables monitoring of motor current and RPM.

Installation

The device can be mounted on a DIN-rail base. Optional enclosure versions are available for different installation environments.

Technical Data EM-352

Supply voltage	Vcc 12–24 V (11–35 VDC)
Overvoltage shut down	40 V
Undervoltage shutdown / start-up	10.5 V / 11 V
Idle current	typ. 30 mA
Max current (continuous)	8 A (Tamb 25 °C)
Max current (peak)	12 A (max 5 s)
Max brake output current	3 A
Brake resistor (min.)	4.7 Ω @ 12 V / 10 Ω @ 24 V
PWM frequency	typ. 16 kHz
Overtemperature shut down	90 °C
Current limit setting	0.1–12 A (step 0.1 A)
Current limit analog scale	0–5 V = 0–15 A
Digital input logic level	“off” = 0–1 V or open / “on” = 4–30 V
Digital input impedance	10 kΩ
Digital input response time	2 ms
Analog input range	0–5 V up to 0–10 V
Analog input impedance	100 kΩ
Analog input filter	100 Hz
Fault output	PNP max Vcc/5 V, max 50 mA
Fan output	NPN max 100 mA (activation temp. 55 °C)
EMC	Measured for industrial environment
PCB flammability class	UL94V-0
Dimensions	65 × 73 × 22 mm
Weight	76 g