On Tue, 9 Oct 2007, Sebastian Kuzminsky wrote: > Date: Tue, 09 Oct 2007 10:33:38 -0600 > From: Sebastian Kuzminsky <[EMAIL PROTECTED]> > Reply-To: "Enhanced Machine Controller (EMC)" > <[email protected]> > To: "Enhanced Machine Controller (EMC)" <[email protected]> > Subject: Re: [Emc-users] hal servo questions > > Sebastian Kuzminsky <[EMAIL PROTECTED]> wrote: >> Jon Elson <[EMAIL PROTECTED]> wrote: >>> You need a lot more voltage supplying the H bridge. At 55% duty >>> cycle, you are getting 12 * 0.55 = 6.6 V at the motor. I am a >>> little surprised the motor doesn't start to turn before this, it >>> must have a lot of friction. Have you measured the motor >>> current just before it starts to turn? That would be >>> interesting to know. >> >> ... >> >> I don't have an oscilloscope, just a cheap multimeter, so I don't think >> I can accurately measure the current just at spinup time. > > Or wait, would this work? I'll put the ammeter inline with one of > the motor leads, and set the duty cycle to just below where it'll turn > the shaft. The power is pulsed so current varies over time, but the > ammeter should average it, right? Maybe if I put it in its AC mode? > > I'll try this tonight. > > > -- > Sebastian Kuzminsky
That should work as long as its a battery operated ammeter, most digital ammeters will average your 2Khz fine, I would use the DC scale. BTW we have several of the what I think are same type of motors (19.1V, 500 count encoder) The ones we have come from HP 7540? plotters. > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
