A system includes a converter operatively connected to an alternating current (AC) power source and a direct current (DC) bus, an inverter operatively connected to a motor and the DC bus, and a controller. The converter includes a first plurality of switching devices in selective communication with each phase of the AC power source and the DC bus. The inverter includes a second plurality of switching devices in selective communication with each phase of the motor and the DC bus. The controller is operable to command dropping of a brake through a passive delay circuit responsive to an emergency stop condition for a load driven by the motor and reduce a voltage on the DC bus by dropping at least one phase of the AC power source and/or using a dynamic braking resistor prior to the brake physically dropping.

A system includes a converter operatively connected to an alternating current (AC) power source and a direct current (DC) bus, an inverter operatively connected to a motor and the DC bus, and a controller. The converter includes a first plurality of switching devices in selective communication with each phase of the AC power source and the DC bus. The inverter includes a second plurality of switching devices in selective communication with each phase of the motor and the DC bus. The controller is operable to command dropping of a brake through a passive delay circuit responsive to an emergency stop condition for a load driven by the motor and reduce a voltage on the DC bus by dropping at least one phase of the AC power source and/or using a dynamic braking resistor prior to the brake physically dropping.

This invention relates to a linear type actuator unit, said actuator unit (100), including an electric motor (1) driving a linear actuator (2) of, said motor (1) having a casing (11), a stator (14,15) fixed to the casing, a rotor (13) fixed to a rotary part (10), preferably a rotary motor shaft (10), wherein said rotary part (10) is arranged to be operatively connected to a reduction gear (5) which drives the mechanical output of the actuator (2), a separate magnetic brake unit (3), said magnetic brake (3) including a rotating brake member (30,31) connected to the motor shaft (10), directly or indirectly, and a plurality of fixed brake members (32, 33), wherein said magnetic brake (3) is arranged to produce a torque that will strive to position a rotary member (10, 20) with said rotating brake member (30,31) into one or more specific angular positions in relation to the fixed brake members (32, 33), and wherein said rotating brake member (30,31) is in the form of a separate annulus (30, 31) attached to said rotary member (10, 20) arranged to brake the motor at low rotational speeds and in that the actuator unit (100) is arranged with a circuitry (101) including a short circuiting arrangement (113, 103) arranged to enable braking of the motor (1) at rotational speeds above low rotational speeds.

This invention relates to a linear type actuator unit, said actuator unit (100), including an electric motor (1) driving a linear actuator (2) of, said motor (1) having a casing (11), a stator (14,15) fixed to the casing, a rotor (13) fixed to a rotary part (10), preferably a rotary motor shaft (10), wherein said rotary part (10) is arranged to be operatively connected to a reduction gear (5) which drives the mechanical output of the actuator (2), a separate magnetic brake unit (3), said magnetic brake (3) including a rotating brake member (30,31) connected to the motor shaft (10), directly or indirectly, and a plurality of fixed brake members (32, 33), wherein said magnetic brake (3) is arranged to produce a torque that will strive to position a rotary member (10, 20) with said rotating brake member (30,31) into one or more specific angular positions in relation to the fixed brake members (32, 33), and wherein said rotating brake member (30,31) is in the form of a separate annulus (30, 31) attached to said rotary member (10, 20) arranged to brake the motor at low rotational speeds and in that the actuator unit (100) is arranged with a circuitry (101) including a short circuiting arrangement (113, 103) arranged to enable braking of the motor (1) at rotational speeds above low rotational speeds.

An angle grinder includes a motor including a rotor and windings, a power supply for supplying power to the motor, a main switch for turning on/off an electrical connection between the windings of the motor and the power supply, an output shaft driven by the rotor to rotate, a rotor brake circuit for slowing down the rotor of the motor when the windings are short circuited or reverse connected, an output shaft brake circuit for producing a magnetic field to slow down the output shaft and a controller for detecting whether the rotor brake circuit short circuits or reverse connects with the windings. When the windings are short circuited or reverse connected for a time which reaches a preset value, the output shaft brake circuit produces the magnetic field to slow down the output shaft.

An angle grinder includes a motor including a rotor and windings, a power supply for supplying power to the motor, a main switch for turning on/off an electrical connection between the windings of the motor and the power supply, an output shaft driven by the rotor to rotate, a rotor brake circuit for slowing down the rotor of the motor when the windings are short circuited or reverse connected, an output shaft brake circuit for producing a magnetic field to slow down the output shaft and a controller for detecting whether the rotor brake circuit short circuits or reverse connects with the windings. When the windings are short circuited or reverse connected for a time which reaches a preset value, the output shaft brake circuit produces the magnetic field to slow down the output shaft.

The invention relates to a joint device, comprising an electric motor, an electrically controllable blocking apparatus), various control apparatuses, and a brake system, in the case of which brake system, in various alternatives, the brake system takes maximum energy from the system by means of active closed-loop/open-loop control or by triggering a (cycled) short circuit whenever possible and only triggers the mechanical blocking as a last resort in order to protect the mechanical and electrical system itself, but nevertheless ensures that the system is securely shut down after a maximum time.

The invention relates to a joint device, comprising an electric motor, an electrically controllable blocking apparatus), various control apparatuses, and a brake system, in the case of which brake system, in various alternatives, the brake system takes maximum energy from the system by means of active closed-loop/open-loop control or by triggering a (cycled) short circuit whenever possible and only triggers the mechanical blocking as a last resort in order to protect the mechanical and electrical system itself, but nevertheless ensures that the system is securely shut down after a maximum time.

A braking device for a movable door leaf according to the invention comprises at least one generator, at the output terminals of which, a generator voltage can be generated, by means of which a charging circuit for supplying an open-loop and/or closed-loop control unit may be charged, by means of which an electric braking device, such as, in particular, a braking motor or the like, is controllable, which generates an effective braking force for damping the movement of the door leafs. Therein, the generator shaft of the generator is rotatable for generating the generator voltage with the discharging of a mechanical generator energy storage specifically associated with the generator, which is charged by a respective opening or closing movement of the door, and, during a respective closing or opening movement of the door, is mechanically decoupled from the same or its axis of rotation, and discharges in the state mechanically decoupled from the door leaf or its axis of rotation. Further specified is a door closer, having a rotatable door closer axis, coupleable with a door leaf, cooperating with a mechanical door closer energy storage device, and a correspondingly designed braking device.

An electric motor-driven parking brake of a motor vehicle can be released in an emergency by applying emergency current from a parallel emergency current source to the motors controlling the parking brake. The direction of the emergency current is selected to reverse the motors, i.e., release the parking brake.