From: "Roger Hamlett"
Subject: Re: Closed loop stepper driver circuit
X-Newsreader: Microsoft Outlook Express 5.50.4807.1700
Date: Wed, 8 Jan 2003 09:45:07 -0000
NNTP-Posting-Date: Wed, 08 Jan 2003 09:45:48 GMT
Organization: ntl Cablemodem News Service
"Kevin Doney" wrote in message
> Anyone know where I can get a stepper driver with encoder feedback or a
> circuit drawing of one?
I would suspect this to be a very unlikely combination.
The point is that the advantage of stepper motors, is their ability to give
accurate angular movement, without the expense of an encoder (provided they
are not overloaded). Servo motors have the 'edge', in terms of low speed
torque, and maximum speed, but at the expense of needing an encoder. If you
are going to add an encoder to a stepper, then a normal servo design,
becomes the more economic (and better) choice....
Hence you see 'simple steppers' - driven with full power pulses, then more
complex 'part step' designs, then encoder based servos, in order of cost.
You may well find some 'checked' servo designs, where a simple 'single
pulse' output shaft encoder is added, to allow the code to verify that the
stepper has not missed some pulses, but I can't really think of any
application where a combination of a more complex encoder and a stepper
would make sense.