|
[DPRG] Re: Pittman GM8712 stats
Subject: [DPRG] Re: Pittman GM8712 stats
From: David P. Anderson
dpa at io.isem.smu.edu
Date: Tue Sep 4 15:22:21 CDT 2001
howdy
Dan Miner wrote:
> Excellent data David! I read the data into Excel and
> plotted DC voltage vs. Ticks/sec. VERY linear as expected.
>
> I have some experiments that you (or someone else)
> may want to try:
>
> 1) Do the numbers match if you reverse the polarity?
> (In other words, do the motors give the same speed for
> the same voltage in reverse?)
Nope. Performance in forward and reverse is close but reverse
not as efficient as forward.
> 2) I'd like to see some experimental (empirical) data to
> verify the recent theoretical discussion of PWM vs. true
> applied voltage. In other words, what % of PWM value do
> you need to get the same speeds when using 19.1V as the
> source voltage. Example: What PWM % value do you need
> to get 434 ticks/sec (=4.0V DC) if you're switching between
> 0V and 19.1V? [Be sure to note PWM frequency.]
I need to dummy up a PWM function that I can vary some of the parameters.
Thought I'd try to do that this week.
> 3) Again using 19.1V source voltage, what is the motor speed
> at different PWM frequencies given the same PWM duty cycle?
> (Example: Always 25% but 200Hz, 500Hz, 1kHz, 2kHZ, 5kHz, 10kHz)
Good question. I'll investigate that also.
> PS - I may have to break down and buy some of these motors
> even though I keep telling myself I should first use up some of
> the robot "parts" I've already accumulated! ;-)
You can't have too many robot motors!!! Get 'em while they're hot!
best regards,
dpa
More information about the DPRG mailing list
|
