1. A drive system for an AC motor having a plurality of coils and a permanent magnet with a plurality of polar elements disposed to become alternating opposite poles, the drive system comprising:
a Hall element sensor measuring a back electromotive force waveform generated by one of the coils and outputting the back electromotive force waveform; and
a rotation control circuit that converts the back electromotive force waveform output from the Hall element sensor into a rectangular waveform,
wherein the rotation control circuit:
provides the rectangular waveform to the plurality of coils until a rotation speed of the AC motor exceeds a prescribed value; and
provides the back electromotive force waveform output by the Hall element sensor to the plurality of coils after the rotation speed of the AC motor exceeds the prescribed value.
2. The drive system according to claim 1, wherein the rotation control circuit reverses a polarity of the back electromotive force waveform so as to change a direction of rotation of the AC motor.
3. A drive circuit for an AC motor having a plurality of coils and a permanent magnet with a plurality of polar elements disposed as alternating opposite poles, the drive circuit comprising:
a first unit receiving a waveform generated by a Hall element sensor, the waveform generated by the Hall element sensor being a back electromotive force waveform generated by one of the coils;
a second unit generating a rectangular waveform, the rectangular waveform being generated by converting the back electromotive force waveform generated by the Hall element sensor; and
a third unit respectively:
providing the rectangular waveform to the plurality of polar elements until a rotation speed of the AC motor exceeds a prescribed value; and
providing the back electromotive force waveform generated by the Hall element sensor to the plurality of polar elements after the rotation speed of the AC motor exceeds the prescribed value.
4. The drive circuit according to claim 3, further comprising a fourth unit for changing a direction of rotation of the AC motor by reversing a polarity of the back electromotive force waveform.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. Apparatus for the variable setting of control times of gas-exchange valves of an internal combustion engine comprising:
an inner rotor and an outer rotor that can rotate relative to the inner rotor,
the inner rotor has a constant phase relationship relative to a crankshaft of the internal combustion engine,
at least one coupling element, in which a drive shaft of an auxiliary assembly can engage,
and, through use of the at least one coupling element, torque can be transmitted from the apparatus to the drive shaft,
the at least one coupling element is locked in rotation with the inner rotor or formed in one piece with the inner rotor.
2. Apparatus according to claim 1, wherein the auxiliary assembly is a vacuum pump.
3. Apparatus according to claim 1, wherein the inner rotor is attached by a central screw to a camshaft and the at least one coupling element is formed on the central screw.
4. Apparatus according to claim 1, wherein a driver is provided, which has the at least one coupling element and which is constructed in one piece with the inner rotor or separately from the inner rotor and locked in rotation with the inner rotor.
5. Apparatus according to claim 4, wherein the separate driver and the inner rotor are attached by a central screw to a camshaft.
6. Apparatus according to claim 5, wherein the driver has a pot-shaped construction, and the central screw passes through a base of the driver.
7. Apparatus according to claim 6, wherein the driver is produced from a sheet-metal part by a non-cutting shaping process.
8. Apparatus according to claim 1, wherein the at least one coupling element is formed as grooves or projections, which are formed complementary to projections or grooves on the drive shaft.
9. Apparatus according to claim 3, wherein the central screw is formed with an essentially axial lubricant channel, to which lubricant can be fed on a camshaft side, and at least one discharge opening is provided in a region of the at least one coupling element.
10. Internal combustion engine with an apparatus for the variable setting of control times of gas-exchange valves of the internal combustion engine and an auxiliary assembly, which is driven by a drive shaft via the apparatus, wherein the apparatus comprises:
an inner rotor and an outer rotor that can rotate relative to the inner rotor,
the inner rotor has a constant phase relationship relative to a crankshaft of the internal combustion engine,
at least one coupling element, in which a drive shaft of an auxiliary assembly can engage,
and, through use of the at least one coupling element, torque can be transmitted from the apparatus to the drive shaft,
the at least one coupling element is locked in rotation with the inner rotor or formed in one piece with the inner rotor.