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Topic: don't understand the meaning of a warning in a motor driver board user guide (Read 2534 times) previous topic - next topic

HaWe

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:

Quote
"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, ....) ?

JimboZA

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Dr Perry Cox: "Help me to help you, help me to help you...."
Your answer may already be here: https://forum.arduino.cc/index.php?topic=384198.0

Jantje


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
Do not PM me a question unless you are prepared to pay for consultancy.
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HaWe

hmmm... so it's supposed to be more Chinglish than English... ?  ;)

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.

Pete
Don't send me technical questions via Private Message.

keeper63


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).
I will not respond to Arduino help PM's from random forum users; if you have such a question, start a new topic thread.

HaWe

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

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