don't understand the meaning of a warning in a motor driver board user guide

hi,
I have a question about the detailed meaning of a warning sentence written in a user guide.
Its related to a motordriver board and it says:

"PWM is not allowed to impending, and it can't long time use high level"

http://www.ebay.de/itm/10A-15A-45A-60A-H-bridge-Dual-DC-Motor-Driver-Controller-Strong-braking-MOSFET-/160910347243

My English is unfortunately very poor (e.g., I don't even understand the word "impending" in this context) - can please someone try to explain in other words what the warning actually means and what kind of technical issues "can't long time use high level" are related to (current, voltage, percentage pwm, stalling, ....) ?

I have a feeling your English is better than theirs.....

JimboZA:
I have a feeling your English is better than theirs.....

Exactly what I was thinking. (In other words:I can't make sense out of it.)

Jantje

hmmm... so it's supposed to be more Chinglish than English... ? :wink:

I also don't understand "impending" in that context.
I think the "can't long time use high level" is related to their spec that "This driver can operate at 0% -99% PWM modulation duty ratio". It is saying you should not drive the motors at 100% (high level) for too long, although they don't specify what a "long time" is.

Pete

el_supremo:
I also don't understand "impending" in that context.
I think the "can't long time use high level" is related to their spec that "This driver can operate at 0% -99% PWM modulation duty ratio". It is saying you should not drive the motors at 100% (high level) for too long, although they don't specify what a "long time" is.

That's exactly what it means.

This driver needs to be driven with a PWM signal only; you can't supply a steady HIGH state (ie - PWM=255) to it, because it likely uses an all N-channel MOSFET design, and needs the PWM switching states to keep the high-side boost circuit running properly. Otherwise, the high-side MOSFETs will stop conducting - I'm not sure if that will cause damage in some manner, it might.

Since they specify a 0-99% PWM rate - if you're using PWM of 0-255, then you would be limited to the values 0-252 (where 252 => 99% of max PWM on the Arduino).

that's very interesting to know, thank you very much for your inputs!