At Oriental Motor, we don't stop improving a product just because it sells. This article takes a deep look at the redesign of our popular BLH Series drivers, how they differentiate from existing drivers, and how they can improve functionality and performance.
The BLH Series compact BLDC motors and drivers have been popular for a long time, and there is a good reason why. Our customers seem to favor the combination of an efficient, compact motor, multiple gear options, and a small, easy-to-use driver.
Over the years, we listened to our customers and heard the need to improve driver functionality, including the ability to digitally set speed rather than rely on analog signals, the need to communicate with host controllers, and the preference for better performance and updated technologies.
The result? We released three new types of drivers: Analog Setting Type, Digital Setting Type, and RS-485 Communication Type.
From RS-485 communication capability to sine-wave drive technology, the improvements don't stop at the driver but also enhance motor performance. Let me tell you what's really different about these redesigned BLH Series drivers.
| Adopting Vector Control |
✅Vector Control
All 3 redesigned BLH Series drivers introduce a major leap in performance with vector control (AKA sine-wave drive), delivering smoother motion, more torque, and higher efficiency than conventional square‑wave drive systems. By precisely controlling the current phase and switching to a sine‑wave drive, the redesigned drivers unlock features like regenerative power handling and reliable torque limiting. Even with standard Hall Effect sensors, these redesigned drivers can intelligently interpolate rotor position to achieve full vector‑control precision.
| Improvement in Performance |
✅Increased Torque
Although there is no design change to the motors, when these redesigned BLH Series drivers are used with existing BLH Series motors, torque performance improves in both the limited-duty and continuous-duty regions. The increased torque can be used to move more load, or accelerate/decelerate faster.
✅Extended Acceleration/Deceleration Range & 3 Stop Modes
With the redesigned drivers, the acceleration/deceleration time setting range has been extended both in the low end and high end. In addtion, 3 "deceleration stop" modes are provided for more flexibility in stopping the motor.
| Type of BLH Series Driver | Acceleration/Deceleration Range |
| Older Drivers (Analog Only) | 0.5~10 seconds |
| New Analog Setting Type Drivers | 0.1~12 seconds |
| New Digital Setting Type Drivers | 0.1~15 seconds |
| Stop Mode | Description |
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Deceleration Stop 1 |
The motor generates a braking force when decelerating to a stop, and operates so as to stop according to the set deceleration time setting. Regenerative power generated by the deceleration of the motor, it is consumed by the motor and driver and won't return to the power supply side. |
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Deceleration Stop 2 |
The motor coasts to a stop by suppressing a braking force at deceleration stop. However, if the deceleration time is shorter than the time that the motor takes to coast to a stop, it will not be applied. |
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Deceleration Stop 3 |
The motor generates a braking force when decelerating to a stop, and operates so as to stop according to the set deceleration time. The regenerative power generated by the deceleration of the motor is returned to the power supply side. |
Why do we offer 3 different ways to decelerate?
For example, in applications such as driving mechanisms for AGVs and AMRs, back EMF generated by back-driving of motors is a major issue. Using Deceleration Stop 1 could help eliminate power supply and driver issues due to back EMF. Using Deceleration Stop 3 could recharge the battery for the vehicle. Just make sure the battery can absorb the regenerative power.
✅Lower Noise
Another nice improvement of the redesigned BLH Series drivers is lower overall noise. These drivers employ the sine-wave drive method. With reduced torque ripple and smooth rotation even at low speeds, the motor's drive noise is reduced by 13 dB.
Watch the video below to get an idea of the difference in noise.
Now I'll go over the differences between each type of driver.
| Analog Setting Type vs Digital Setting Type |
Although the redesigned Analog Setting Type driver already uses sine-wave drive technology, the Digital Setting Type driver offers more functions than the Analog Setting Type driver, such as more ways to set speed and the addition of a torque limiting function. The acceleration/deceleration time setting is also widened by the Digital Setting Type.
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Use the MEXE02 support software with a digital setting type driver to access functions ⑦ to ⑭. |
✅Motor Connector Location
Let's take a look at the following images for comparison. Notice that for the new drivers, the motor connector is now on the left side instead of right side. There's a USB connector on the digital setting type drivers. Please use a USB2.0 cable to connect to your PC after installing the MEXE02 software.
| Older BLH Series Driver | Redesigned BLH Series Drivers |
| Analog Setting Type | Analog Setting Type | Digital Setting Type |
①Power Connector
②I/O Signal Connector
③Motor Connector
④USB Connector (for digital setting type)
Note: The I/O connector pin assignment may have changed depending on the driver type, so please verify before connecting.
✅PWM Input
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The Digital Setting Type driver can also accept a PWM signal from the PLC to set speed instead of using an external DC voltage. This could help eliminate the extra cost of an analog card on the PLC. |
| Benefits of the Digital Setting Type and RS-485 Communication Type Drivers |
The older BLH Series drivers with square-wave drive technology were the original Analog Setting Type. Analog Setting Type drivers allow the speed(s) to be set by an analog voltage signal. This signal can be provided by an internal potentiometer, an external potentiometer, or a 0~5VDC external signal.
The problem with analog signals is their tendency to vary due to cable resistance changes.
The Digital Setting Type driver includes more features and functions to improve the overall performance and ease of use. Along with adding sine-wave drive technology, compatibility with our MEXE02 universal data setting software is also introduced for easier digital setting of data and better troubleshooting. I'll explain more later.
To meet predictive maintenance requirements or reduce wiring requirements, an RS-485 Communication Type driver is available. Two communication ports are added as well as MEXE02 support software compatibility. Once connected to a upper level host controller, this driver will be able to send real-time updates on various status data. Specifications such as speed regulation and speed range will be the same as the Digital Setting Type driver.
| Digital Setting Type | RS-485 Communication Type |
The Digital Setting Type and RS-485 Communication Type drivers are not offered for 100 W motors at this time.
✅MEXE02 Support Software
For both the Digital Setting Type and RS-485 Communication Type drivers, one major design change was adding a USB connector on the driver board and compatibility with the
One advantage is obviously the ability to set motion data and parameters by digitally setting them instead of flipping tiny dip switches or relying on analog signals, but there are many more.
✅Better Speed Regulation, More Data Sets, and Wider Speed Range
With the MEXE02 software, 8 speed data sets can be programmed and set within the stored data bank of the driver. With the older analog setting drivers, only 2 speeds can be set by a potentiometer or an analog DC voltage.
With digital speed setting, the speed range is also widened a little bit on the low end (100~3,000 RPM vs 80~3,000 RPM), which opens up the BLH Series for more low speed applications.
✅I/O Function Selection
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With the MEXE02 software I/O function selection, the user can assign the input function they need instead of something that's not necessary for the application. Even though you have 6 inputs and 4 outputs physically available, there are more functions you can assign based on your preference. |
✅Torque Limiting
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Torque limiting is a function to limit the motor's torque to a percentage of the rated torque (100%) by using current and feedback. |
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| For applications such as pressure-sensitive stamping, pressing, capping or screwing operations, a built-in torque limit function can be very useful. |
✅Teaching Operation and Data Copy Function
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The teaching operation allows speeds to be taught by the software's speed toggle function. For data synchronization between multiple drivers, a data copy function is available. |
✅Remote Monitoring and Predictive Maintenance
Remote monitoring allows monitoring of system status in real time through the MEXE02 software. Through this function, data such as speed, load factor, driver temperature, load, tripmeter, odometer, I/O status, alarm codes, and power cycles can be monitored by the software. For predictive maintenance, information bit outputs can be easily configured and sent to the PLC by RS-485 communication standard and Modbus (RTU) protocol.
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| Summary |
The redesigned BLH Series compact BLDC drivers deliver higher torque, faster acceleration and deceleration, and greater stopping flexibility, all without changing the motors themselves. Users gain improved performance through extended accel/decel ranges, three new regenerative‑friendly stop modes, and the option to choose analog, digital, or RS‑485 driver types. These enhancements help reduce tact time, improve control, and solve issues like back‑EMF in applications such as AGVs and AMRs—making the updated drivers more powerful, more flexible, and easier to integrate.
TIP Make sure to use BLH Series drivers with part numbers starting with "BLH2D" for the redesigned sine-wave drivers. FYI part numbers for the older drivers with square-wave drive technology begins with just "BLHD".
Demo Watch the BLH Series drive an AGV
For brushless motors higher than 1/8 HP (100 W) combined with DC input drivers, we recommend the BLV Series R Type. For help finding the most suitable product for your specific application, please contact our technical support team.