Abstract: Angular position and rotation rate of a function generator having stator windings and rotor windings are determined by first amplitude modulating a carrier oscillation to form a sine signal and a cosine signal and then feeding the sine signal and cosine signals to opposite stator windings and thereby inducing in the rotor winding an analog function-generator signal. In turn this analog function-generator signal is converted into a digital function-generator signal from which is derived by means of an algorithm a digital rotation-rate signal which is numerically integrated to obtain an angular-position signal. This angular-position signal is itself used to modulate the carrier oscillation.

Abstract: A circuit for protecting a switching transistor connected between a direct-current voltage source and an inductive load has a voltage-limiting element connected between the source and the transistor for switching the transistor when the voltage of the source exceeds a predetermined limit, elements for deriving from the voltage-limiting element a control signal when the source voltage exceeds the predetermined limit, and a variable pulse-width modulator connected to a control input of the transistor and receiving the signal from the means. The modulator decreases pulse width when the source voltage exceeds the limit.

Abstract: A multiple bolt turning machine comprises a winding star which is adapted to rotate a bolt being wound with a web of material from a bolt winding position to a bolt removal position. A feed roll engages the incoming web of material at the bolt winding position, and as the winding star rotates to move the bolt from the winding position to the removal position the feed roll is also repositioned to remain in contact with the bolt, and is concurrently moved in a direction transverse to the axes of rotation of the winding star and feed roll to keep the angle of contact between the feed roll and the web of material substantially constant throughout the movement of the bolt between said winding and removal positions.