Abstract:
An actuator comprising a reversible electric motor, which over a gearing, drives an activation element which can move back and forth. The activation element is of the non-self-locking type. Furthermore the motor and gearing are of a non self locking type. A brake holds the activation element in any position, when the electric motor is inactive, said brake can be released by means of a release mechanism. The motor is used as generator when the brake is released and the generator voltage from it is used to adjust the velocity of the activation element. Thus, a quick release is provided, where the activation element can be disengaged and adjusted evading gear and motor, and where the movement of the activation element, during the disengagement, occurs with a controlled velocity.
Abstract:
In an electronic system, motor braking is accomplished by applying direct current (DC) voltage, developed across a capacitive element during a run mode operation, across terminals of an alternating current (AC) or an induction motor. While the motor is ON, i.e. during the run mode operation, a diode rectifies an AC input voltage applied across a capacitor for charging thereof. Resistive elements in series with the capacitor control a charging rate thereof. When a relay or switch flips over to a STOP or OFF mode, i.e. a braking mod operation, all of the stored DC voltage, which was charged across the capacitor during the run mode operation, is dropped across a coil of the motor. This DC voltage creates an electric force applied to stop quickly and efficiently the motor shaft rotation. In preferred embodiments of the invention, it was found that the higher the capacitance of the electrolytic capacitor, the faster and more efficient the stopping action will be for the motor.
Abstract:
A synchronous alternating current generator incorporates a braking mechanism which comprises a coil (21) providing a predetermined inductance and a predetermined resistance, and switch means (22) for connecting the coil across an output of the generator.
Abstract:
A motor actuator (10) for preventing a motor (m) from drawing excess current for longer than a predetermined time delay period including dynamic brakes for simultaneously braking motor rotation when motor (m) operation is terminated for any reason. Source voltage supplies an input to a voltage regulator (18) which in turn supplies a regulated voltage to the motor (m). The actuator (10) includes a comparator circuit (26) that has one input connected to motor (m) supplied regulated voltage and a second input connected to the source voltage with the voltage level from source voltage adjusted to a level that is equal to the regulated motor voltage level under normal motor operational loads. When the motor (m) draws excessive current the voltages on the comparator (26) inputs become unequal which caused the comparator (26) to have an output voltage. An RC circuit from the comparator output to ground potential delays the comparator output voltage for a predetermined time. When the predetermined time is exceeded voltage appears on the comparator output causing a switching element, shown as a relay, to switch the motor supply voltage off and Mos Fet conducts providing rotational braking when power is removed from the motor.
Abstract:
A braking system for a vehicle powered by DC motor, such as a battery powered locomotive, is arranged to connect a bridging conductor (16) across the motor to brake the vehicle in an emergency. The system engages when the armature voltage of the motor reaches a predetermined threshold, and operates to disconnect the power supply to the motor, to reverse the series-connected field winding of the motor and to connect the bridging conductor (16) across the armature (A) and the field winding to brake the motor in an emergency. The resultant braking effect is self regulating.