Back to results
US 8,796,964 B2Granted
Controllable direct current motor having a modified characteristic
AssigneeC. & E. Fein GmbH
InventorsLothar Dietl, Alfred Schreiber, Richard E. Geitner
Life of this patent
Estimating the term…
Abstract
A direct-current motor is disclosed, preferably in the form of an EC motor, which has a matching arrangement in order to vary its rotation-speed/torque characteristic, having a permanently effective control circuit for controlling the motor, which control circuit is programmed such that the rotation-speed/torque characteristic is permanently varied with respect to rated operation or operation with the matching arrangement.
Claims20
An electric motor system comprising:
- a direct current motor having a rated speed/torque relationship;
- an electronically controllable switching arrangement that weakens an induced back-emf;
- and
- a control circuit that continuously controls said direct current motor, said control circuit permanently altering a speed/torque relationship of said direct current motor from said rated speed/torque relationship while said switching arrangement simultaneously actively controls weakening of said induced back-emf.
1 more element
An electric motor system, comprising:
- a direct current motor having a rated speed/torque relationship;
- an electronically controllable switching arrangement that weakens an induced back-emf;
- and
- a PWM control circuit that continuously controls said direct current motor, said PWM control circuit permanently altering a speed/torque relationship of said direct current motor from said rated speed/torque relationship while said switching arrangement simultaneously actively controls weakening of said induced back-emf, for effecting a desired operating characteristic of said direct current motor that is thermally permissible during rated operation.
1 more element
An electric motor system, comprising:
- a direct current motor having a rated speed/torque relationship;
- an electronically controllable switching arrangement that weakens an induced back-emf, said switching arrangement being selected from the group consisting of a star delta coil switching arrangement, a switching arrangement that switches coils between a series and a parallel arrangement, and a coil group switching arrangement configured for switching coil groups between series and parallel arrangement;
- and
- a PWM control circuit that continuously controls said direct current motor, said PWM control circuit permanently altering a speed/torque relationship of said direct current motor from said rated speed/torque relationship while said switching arrangement simultaneously actively controls weakening of said induced back-emf, for effecting a desired operating characteristic of said motor that is thermally permissible during rated operation.
1 more element
Dependencies are inferred from the claim text.