EM-347B is a brushless DC motor driver with Hall sensor feedback and an efficient MOSFET power stage. The driver supports 120° commutation and includes a true 4-quadrant power stage, enabling regenerative braking.
During regenerative braking, the supply voltage rises. This rise can be controlled using a braking resistor. In battery-powered systems, the regenerated energy can be returned to the battery, eliminating the need for a braking resistor.
The EM-347B includes digital command inputs for direction, brake, start/stop, and disable. Analog inputs are provided for speed and current-limit control.
A digitally presettable second speed, speed-2, can be activated using a digital command input.
Two NPN outputs are available for fault and overcurrent indication. Several input and output functions can be modified using parameters.
The true 4-quadrant power stage allows the motor to operate in both directions and provides controlled regenerative braking.
Regenerative energy raises the DC supply voltage. A suitable braking resistor can be connected to limit this rise. When the driver is supplied from a rechargeable battery, the regenerated energy can be returned to the battery.
The driver includes protection against overvoltage, undervoltage, and overtemperature. Fault conditions are indicated by an on-board fault LED.
Overtemperature and current-limit conditions can be cleared using a reset input, a reset timer, or by setting the analog speed command to zero.
The EM-347B provides two selectable speed control modes:
Start and stop ramps operate in both modes. The speed range, closed-loop RPM range, and ramp times can be adjusted using parameters.
The filtered analog inputs can be used for both speed and current-limit control. They support analog control ranges from 0–5 V up to 0–10 V.
The input filtering also allows PWM signals to be used for speed and current-limit control.
Parameters can be configured using the EM-236 Interface Unit. PC-based configuration is available using EmenTool Lite together with the EM-268 adapter cable.
Parameter settings are stored in the driver’s non-volatile memory. The interface can also be used to monitor motor current and RPM.
The shutdown input places the driver in a low-power state. Idle current in shutdown mode is approximately 0.2 mA when the shutdown input is connected to GND.
The integrated RS-485 interface supports Modbus RTU communication at 9600 or 19200 baud. It can be used for control, parameter access, and communication with external automation systems.
An optional cooling fan can be connected to the dedicated 12 V fan output. The output switches on automatically when the driver temperature rises above 65°C.
The device can be installed on a DIN-rail mounting base. Enclosure options are also available for different installation requirements.
| Supply voltage | 12–48 V nominal (11–60 VDC) |
| Overvoltage limit | 15–65 V, adjustable |
| Idle current | Typ. 30 mA |
| Idle current in shutdown | 0.2 mA (shutdown connected to GND) |
| Maximum continuous current | 50 A at Tamb = 50°C |
| Maximum continuous current with fan | 60 A |
| Maximum peak current | 80 A for max. 5 s |
| Maximum brake output current (pin 21) | 20 A |
| Recommended brake resistor | 1.5–10 Ω |
| PWM frequency | Typ. 16 kHz |
| Overtemperature shutdown | 90°C |
| Fan output switch-on temperature | > 65°C |
| Current-limit setting | 1–100 A in 1 A steps |
| Current-limit analog scale | 0–5 V = 0–100 A |
| Digital input OFF level | 0–1 V or open |
| Digital input ON level | 4–30 V |
| Digital input impedance | 10 kΩ |
| Shutdown input | Open or < 1 V = low-power mode |
| 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 |
| RS-485 | 9600 / 19200 baud, Modbus RTU |
| Overcurrent output | NPN, max. 2 A / 60 V |
| Fault output | NPN, max. 50 V / 50 mA |
| Fan cooling output | 12 V, max. 100 mA |
| EMC | Measured for industrial environment |
| PCB flammability class | UL94V-0 |
| Dimensions | 140 × 122 × 43 mm (56 mm with fan) |
| Weight | 520 g (550 g with fan) |
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