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NEWSLETTER AUGUST 2000

www.awrtech.co.uk

MICROSTEP DRIVE BOX The drive box is the front line part of the Intelligent Drive System that controls the motors. The positioning performace of this is critical. Work has been completed on examining the linearity of the microstep sequence. Extensive investigation has removed completely the pole cogging effect whilst retaining a constant torque. The whole sequence has been revised to smooth out the torque to make it substantially constant. For a stepper motor to deliver torque it must take up an angle to the unloaded position and this appears as a backlash component. Further, no matter where in the sequence the backlash must be the same amount. This has resulted in a new issue of the Translation Table used in this drive box.

Issue A of the table is sufficient when the torque reqirement is low or the telescope reduction ratio is above 350:1 when the 64 microstep period is just over 1 second. Issue B should be used on smaller reduction ratio's or in the presence of a large torque requirement (over 30% of motor rated load).

INTELLIGENT HANDSET

The INTELLIGENT HANDSET is now available with TWO STAR CALIBRATION. A new approach is being used by AWR with this release of software. The correct way to drive equatorial mounts is by driving the polar axis only, which relies on getting the polar axis aligned spot on (very difficult). The software we have developed generates an error value for azimuth and altitude of the polar axis. Knowing this it is then easy to correct the alignment. The RA drive should then be correct. Evaluation and testing shows this procedure works and can be accomplished in minutes.
Intelligent Drive System data sheet is at http://www.awrtech.co.uk/ih/

We are currently shipping software versions V1.2 (IH), V0.57 (Microstep).
Software upgrades are available free of charge to existing customers. There will be a small charge (for postage) if you return goods for us to fit the upgrades.

GALLERY If you have a picture of equipment using our drives, or photographs taken through telescopes driven by our equipment then you are invited to send in some pictures to post on our new GALLERY page. We already have a stunning picture of the Dumbbell Nebula (M27) driven by our SYSTEM 4 taken through a 20" Newtonian with autoguiding.

MISCELLANEOUS A variety of equipment can be supplied including RONCHI gratings, PTFE, Mains Power Supplies, technical articles on various topics etc etc. Please see our main web page and price list for the full catalogue.

If you wish to see products before purchase then it is possible to view at our premises by appointment, please phone first. There is normally some equipment being built to show.

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AWR Technology The Old Bakehouse Albert Rd, DEAL, Kent CT14 9RD	alan@buckman-hardy.co.uk 01304 365918