Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
51 words
A method of controlling the damping of stepper motor movement characterised by, sensing at least at the penultimate step which windings are receiving current. switching current to the appropriate winding or windings in accordance with the step sequence, and short circuiting the windings not being supplied with current or switched off.
Claim 2
Independent Claim
51 words
A method of controlling the damping of stepper motor movement characterised by, sensing at least at the penultimate step which windings are receiving current. switching current to the appropriate winding or windings in accordance with the step sequence, and short circuiting the windings not being supplied with current or switched off.
Claim 3
Dependent Claim
84 words
Apparatus for controlling the damping of movement of a stepper motor characterised in that short-circuiting means (1, 2) are connected in parallel with each winding (A, B, C, D) of the stepper motor, said short-circuiting means being connected to control means, whereby in use, the windings not receiving current are short-circuited in response to signals from said control means and a path is provided for the back electro-motive force (EMF) induced in the windings not receiving current, said back EMF producing a damping effect.
Claim 4
Dependent Claim
84 words
Apparatus for controlling the damping of movement of a stepper motor characterised in that short-circuiting means (1, 2) are connected in parallel with each winding (A, B, C, D) of the stepper motor, said short-circuiting means being connected to control means, whereby in use, the windings not receiving current are short-circuited in response to signals from said control means and a path is provided for the back electro-motive force (EMF) induced in the windings not receiving current, said back EMF producing a damping effect.
Claim 5
Dependent Claim
56 words
Apparatus as claimed in claim 2 characterised in that said short-circuiting means is a pair of transistors (1, 2) connected in parallel with each other and with a respective winding (A), the transistors (1, 2) being connected in opposite polarity whereby a short-circuit is provided across the winding regardless of polarity of EMF across the winding.
Claim 6
Dependent Claim
43 words
Apparatus as claimed in claim 2 characterised in that said short-circuiting means is a pair of PNP transistors or any other type of switchable elements connected in parallel with each other and with a respective winding the elements being connected in opposite polarity.
Claim 7
Dependent Claim
37 words
Apparatus as claimed in claim 4 characterised in that each switchable element is connected to a microprocessor which controls the switching on and off of said switchable element in accordance with the position of the last step.