초록 ▼

The present invention relates to a braking system for a DC motor. The braking system includes a current control element placed across the terminals of the DC motor to regulate the magnitude of the electric current generated by the motor when the motor is in a braking mode of operation. In the most p

The present invention relates to a braking system for a DC motor. The braking system includes a current control element placed across the terminals of the DC motor to regulate the magnitude of the electric current generated by the motor when the motor is in a braking mode of operation. In the most preferred embodiment, the current control element includes a semiconductor switch, such as a transistor, that is repeatedly pulsed on and off to act as a controlled short circuit across the armature of the motor. The rotational energy is dissipated as heat by the inherent resistance of the motor windings that may be augmented by an external resistor, if desired. Another possibility is to use a current control element that includes a variable load designed to dissipate the rotational energy in the form of heat. The impedance of the load element is gradually reduced as the speed of the motor is reduced to maintain the rate of energy dissipation near the peak allowable value for the structure of the DC motor. This feature permits to reduce the speed of the motor very rapidly.

대표청구항 ▼

1. A braking system for a DC motor including first and second terminals, said braking system adapted to be connected across the first and second terminals of the DC motor when the DC motor acquires a braking mode of operation, the DC motor characterized by a maximum braking current value in the brak

1. A braking system for a DC motor including first and second terminals, said braking system adapted to be connected across the first and second terminals of the DC motor when the DC motor acquires a braking mode of operation, the DC motor characterized by a maximum braking current value in the braking mode of operation, said braking system including:a power supply capable of drawing electrical energy from the first and second terminals of the DC motor when said braking system is connected across the first and second terminals; a current control element receiving electrical power for operation from said power supply, said current control element operative to regulate a magnitude of a current passing through the windings of the DC motor for braking the DC motor, whereby an average magnitude of the current over a braking cycle of the DC motor is substantially equal to the maximum braking current value during a major portion of the braking cycle.