[ger21]

Progress is being made.

Mariss

Any progress in the last year??

[Mariss Freimanis]

Lots of progress.

G201X. Improved G201 replacement. Done; waiting for production boards.
G320X. Much improved G320 and G340replacement. Done; waiting for production boards.
G380X. Full-feature version of the G320X. In board layout, 2 weeks from done.
G250X/G251X. Improved G250/G251replacements. Layout finished, being proofed.
G213X. Much improved G203V replacement. In design, breadboard stage.
Step-servo. Last item on my 'future list'. When it's done, I'm taking a very long vacation.

Mariss

[tooManyHobbies]

Lots of progress.
G250X/G251X. Improved G250/G251replacements. Layout finished, being proofed.Mariss

What are the improvements on the 250/251?

tom

[Mariss Freimanis]

I think the most important one is adding recirculation switching mode during standby. Please see the attached picture:

The red trace shows measured motor heating versus power supply voltage using a G201 or a G250; both give the same results. The motor is a low inductance (1.6mH) NEMA-23 rated at 3.5A. The motor can dissipate about 10W to 12W without overheating.

This test was run on a G201, then the new G201X out to 80VDC. It seemed unwise to take data at 100VDC because the motor would have hit at least 80W during standby. Drawn-in are the results at 50VDC, the G250 limit.

At 50VDC, the red trace shows this motor dissipating 17.5W using a G201 or G250. The motor gets very hot even in standby.

Using a G201X (or G250X), the blue trace shows the motor dissipating a very comfortable 4.2W, over 4 times less than with a G201 or G250. This motor stays cucumber-cool at 50VDC during standby while the red trace one would be stinking hot.

Nothing can be done about heating while the motor is turning using conventional step motor drives. Luckily most applications have a motor duty cycle where the motor is stopped for periods of time. Recirculation allows the motor to cool-off during these stopped times.

A four-fold reduction in motor heating (17.5W / 4.8W) is a significant improvement. It will be included in the next revision of the G250/G251.

Mariss

[BobF]

Lots of progress.

G201X. Improved G201 replacement. Done; waiting for production boards.
G320X. Much improved G320 and G340replacement. Done; waiting for production boards.
G380X. Full-feature version of the G320X. In board layout, 2 weeks from done.
G250X/G251X. Improved G250/G251replacements. Layout finished, being proofed.
G213X. Much improved G203V replacement. In design, breadboard stage.
Step-servo. Last item on my 'future list'. When it's done, I'm taking a very long vacation.

Mariss

Could one infer a G540X in the future as well?

[Mariss Freimanis]

The "X" in the part name refers to the CPLD used, a Xilinx CoolRunner II XC2C.. part number. The G540 already uses them so it's already there.:-)

Mariss

[raymondg]

Any progress or timeframe for the "stepper servo drive"? When I first read about it 2 years ago, I was really excited, but didn't have an immediate need. Now I have an application, and am hoping they will be available soon.

Raymond

[beliefdrive]

hi Mariss, how about step servo project

[Mariss Freimanis]

Working on it.:-) This should give you some idea how long it takes to develop a new drive.

Mariss

[DieselPower]

Glad this project is still ticking along! BTW, is the G-Rex still being sold behind the scenes? and will it be required for the stepper-servo driver system?

[beliefdrive]

http://www.csuohio.edu/engineering/e...004/Bhavin.pdf

i hope it useful for anybody want try step motor foc control