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Products => Crowd Funded Projects => Topic started by: cdoerfler on October 17, 2019, 10:00:37 pm

Title: Power H Mini: Open Source Full H Bridge 12A DC Motor Driver
Post by: cdoerfler on October 17, 2019, 10:00:37 pm
Hello everybody. My company, SAM Controllers, has developed a full H bridge 12A DC motor driver using the VNH7100AS from ST Microelectronics Datasheet: https://www.st.com/resource/en/datasheet/vnh7100as.pdf (https://www.st.com/resource/en/datasheet/vnh7100as.pdf)

The Power H Mini is a robust DC motor full H bridge driver that is useful for a variety of applications. With simple two wire control and PWM, this is a plug and play driver that ensures smoother movement of motors in each direction with complete active coupling for accuracy during precision movement. An extremely low internal resistance for the final stage provides high efficiency, low heat dissipation, and extreme recuperation of energy. 

This driver provides a lot of flexibility for custom DC motor applications. It is designed for full bridge control with a single motor, for two motors to be controlled with two half bridges or for three motors to be controlled with mechanically dependent configurations.  For many usage scenarios up to 5A, a heat sink can be avoided or significantly reduced.

In addition, this driver has a pinout and interface that are nearly identical to A4988, DRV8825 and similar board drivers, so it can be used as a higher-performance drop-in replacement for those boards in many applications.

We have used this internally in our own projects and shared it among our friends. With all of the great feedback we have received, we have decided to open it up and launch it on a crowdfunding site to gain some more exposure and scale up the production.

The Github account for SAM Controllers is https://github.com/SAM-controllers/SAM-VNH7DC12A-Demo (https://github.com/SAM-controllers/SAM-VNH7DC12A-Demo)

The Power H Mini campaign prelaunch page is https://www.crowdsupply.com/sam-controllers/power-h-mini-v2 (https://www.crowdsupply.com/sam-controllers/power-h-mini-v2)

Please take a look and let me know what you think.

Thank you!

(https://samcontrollers.com/wp-content/uploads/2018/11/front-view-large.jpg)
(https://samcontrollers.com/wp-content/uploads/2018/11/front-c1-quarter.jpg)
(https://samcontrollers.com/wp-content/uploads/2018/11/front-c1-large.jpg)
Title: Re: Power H Mini: Open Source Full H Bridge 12A DC Motor Driver
Post by: thm_w on October 17, 2019, 10:04:12 pm
Do you think those pin headers can handle 12A?
Title: Re: Power H Mini: Open Source Full H Bridge 12A DC Motor Driver
Post by: cdoerfler on October 17, 2019, 10:26:09 pm
Do you think those pin headers can handle 12A?

With these pin headers, we advise on this design for 7A.

The chip is designed for up to 15A. If you would like a full 12A system, we can design.

After the crowdfunding campaign, we will know more about what the market wants. If desired, we will likely offer alongside at a slightly higher cost.
Title: Re: Power H Mini: Open Source Full H Bridge 12A DC Motor Driver
Post by: langwadt on October 17, 2019, 10:59:15 pm
Do you think those pin headers can handle 12A?

With these pin headers, we advise on this design for 7A.

The chip is designed for up to 15A. If you would like a full 12A system, we can design.

After the crowdfunding campaign, we will know more about what the market wants. If desired, we will likely offer alongside at a slightly higher cost.

7A^2 * 200mOhm = 9.8W I have a hard time seeing that work, and with PWM the EMI friendly microsecond switching is just going to make that worse

Title: Re: Power H Mini: Open Source Full H Bridge 12A DC Motor Driver
Post by: cdoerfler on October 17, 2019, 11:29:08 pm
Do you think those pin headers can handle 12A?

With these pin headers, we advise on this design for 7A.

The chip is designed for up to 15A. If you would like a full 12A system, we can design.

After the crowdfunding campaign, we will know more about what the market wants. If desired, we will likely offer alongside at a slightly higher cost.

7A^2 * 200mOhm = 9.8W I have a hard time seeing that work, and with PWM the EMI friendly microsecond switching is just going to make that worse

Clearly it is all about the usage. If the point is to max the power out, the results will be what you seek. Feel free to compare with the A4988 and DRV8825 to see the difference.
Title: Re: Power H Mini: Open Source Full H Bridge 12A DC Motor Driver
Post by: Ian.M on October 18, 2019, 01:01:37 am
Its going to be tough to beat the official VNH7100 eval board (https://www.digikey.com/product-detail/en/stmicroelectronics/EV-VNH7100BAS/497-18133-ND/9487323) at under $5.50 USD, which has enough parallel header pins and copper area for heatsinking to reasonably be able to deliver the chip's rated current.

I just hope there's enough of a niche market for a miniature board that can only go up to 15A transiently with a very low duty cycle.  Hope you've made those supply and output tracks beefy enough to handle 15A for a few seconds without burning up or fusing!
Title: Re: Power H Mini: Open Source Full H Bridge 12A DC Motor Driver
Post by: Kean on October 20, 2019, 03:02:49 pm
In addition, this driver has a pinout and interface that are nearly identical to A4988, DRV8825 and similar board drivers, so it can be used as a higher-performance drop-in replacement for those boards in many applications.

That is a pretty weird comparison considering the VNH7100AS is a single high current H-bridge driver, and the A4988 and DRV8825 are microstepping bipolar stepper motor drivers.
Sure your module has a "similar" footprint, with "similar" pinout allocations, but the functionality is quite different and they are far from being a drop-in replacement.
Title: Re: Power H Mini: Open Source Full H Bridge 12A DC Motor Driver
Post by: cdoerfler on October 22, 2019, 12:15:23 am
In addition, this driver has a pinout and interface that are nearly identical to A4988, DRV8825 and similar board drivers, so it can be used as a higher-performance drop-in replacement for those boards in many applications.

That is a pretty weird comparison considering the VNH7100AS is a single high current H-bridge driver, and the A4988 and DRV8825 are microstepping bipolar stepper motor drivers.
Sure your module has a "similar" footprint, with "similar" pinout allocations, but the functionality is quite different and they are far from being a drop-in replacement.


My apologies, the pinout is for size comparison, not functionality.

A couple of comparable drivers (although higher peak current) can be found here, https://core-electronics.com.au/motor-driver-2a-dual-l298-h-bridge.html (https://core-electronics.com.au/motor-driver-2a-dual-l298-h-bridge.html) with the L298 datasheet, here https://www.sparkfun.com/datasheets/Robotics/L298_H_Bridge.pdf (https://www.sparkfun.com/datasheets/Robotics/L298_H_Bridge.pdf)

and here

https://www.handsontec.com/dataspecs/module/BTS7960%20Motor%20Driver.pdf (https://www.handsontec.com/dataspecs/module/BTS7960%20Motor%20Driver.pdf) using the BTS7960 datasheet here, https://www.datasheet4u.com/datasheet-parts/BTS7960-datasheet.php?id=705262 (https://www.datasheet4u.com/datasheet-parts/BTS7960-datasheet.php?id=705262)

The advantage of our product is that we are using the VNH7100AS, datasheet here, https://www.st.com/resource/en/datasheet/vnh7100as.pdf (https://www.st.com/resource/en/datasheet/vnh7100as.pdf) The ultra low resistance of this chip delivers more power at higher efficiencies which will allow for the motor to have a steeper acceleration and deceleration curves without dissipation of heat on the controller.

Title: Re: Power H Mini: Open Source Full H Bridge 12A DC Motor Driver
Post by: langwadt on October 22, 2019, 12:23:51 am
In addition, this driver has a pinout and interface that are nearly identical to A4988, DRV8825 and similar board drivers, so it can be used as a higher-performance drop-in replacement for those boards in many applications.

That is a pretty weird comparison considering the VNH7100AS is a single high current H-bridge driver, and the A4988 and DRV8825 are microstepping bipolar stepper motor drivers.
Sure your module has a "similar" footprint, with "similar" pinout allocations, but the functionality is quite different and they are far from being a drop-in replacement.


My apologies, the pinout is for size comparison, not functionality.

A couple of comparable drivers (although higher peak current) can be found here, https://core-electronics.com.au/motor-driver-2a-dual-l298-h-bridge.html (https://core-electronics.com.au/motor-driver-2a-dual-l298-h-bridge.html) with the L298 datasheet, here https://www.sparkfun.com/datasheets/Robotics/L298_H_Bridge.pdf (https://www.sparkfun.com/datasheets/Robotics/L298_H_Bridge.pdf)

and here

https://www.handsontec.com/dataspecs/module/BTS7960%20Motor%20Driver.pdf (https://www.handsontec.com/dataspecs/module/BTS7960%20Motor%20Driver.pdf) using the BTS7960 datasheet here, https://www.datasheet4u.com/datasheet-parts/BTS7960-datasheet.php?id=705262 (https://www.datasheet4u.com/datasheet-parts/BTS7960-datasheet.php?id=705262)

The advantage of our product is that we are using the VNH7100AS, datasheet here, https://www.st.com/resource/en/datasheet/vnh7100as.pdf (https://www.st.com/resource/en/datasheet/vnh7100as.pdf) The ultra low resistance of this chip delivers more power at higher efficiencies which will allow for the motor to have a steeper acceleration and deceleration curves without dissipation of heat on the controller.

 the VNH7100AS has much higher on resistance than the BTS796
Title: Re: Power H Mini: Open Source Full H Bridge 12A DC Motor Driver
Post by: Kean on October 22, 2019, 04:35:01 pm
My apologies, the pinout is for size comparison, not functionality.

You should have the page at Crowd Supply modified then.  It is very misleading, and clearly says it can be a drop-in replacement for a stepper driver, just like your original post above.

Quote
In addition, this driver’s pinout and interface are nearly identical to those of the A4988, the DRV8825, and similar board drivers. In many applications, it can be used as a higher-performance drop-in replacement for those boards.
Title: Re: Power H Mini: Open Source Full H Bridge 12A DC Motor Driver
Post by: cdoerfler on October 24, 2019, 09:39:59 pm
Power H Mini is an open-source, high current, full H-bridge driver that provides a lot of flexibility for DC motor applications. It is designed for full bridge control with a single motor, for two motors to be controlled with two half bridges, or for three motors to be controlled with mechanically dependent configurations.

The streamlined design coupled with the extremely low internal resistance results in a low amount of heat dissipation on the driver translating into improved control when accelerating, or braking. In robotics, this improved energy recuperation means that motors have much steeper, more controlled acceleration curves and also brake faster and evenly without dissipation of heat on the controller.

With simple two wire control and pulse-width modulation (PWM), this plug-and-play driver ensures smoother movement of motors in each direction including complete active coupling for improved accuracy during precision movement.


The high efficiency and low heat dissipation makes this an ideal solution where space and heat are design constraints. The pinout and interface are nearly identical to A4988, DRV8825 and similar board drivers with a 15mm x 20mm board size, however this is a DC motor driver, so it competes in functionality with H-bridge motor drivers based on the L298 or BTS7960 transistor technology which is typically delivered in a module 2-3x the size (~35mm x ~60mm).

For many usage scenarios up to 5 A, a heat sink can be avoided or significantly reduced. With a peak current limit of 12 A, this board delivers a surprising level of motor control in a tiny package.