Pulse width modulated drive for an infinitely variable solenoid operated brake cylinder pressure control valve
First Claim
1. A pulse width modulated drive circuit for driving a solenoid operated valve in response to an input voltage signal from a brake control apparatus, said solenoid operated valve including a coil that is energizable in response to energy received from said drive circuit, said drive circuit comprising:
- (a) a pulse generator circuit for receiving said input voltage signal from said brake control apparatus and a feedback signal derived from said coil and for generating in response thereto a pulse width modulated signal whose duty cycle depends thereon;
(b) an output circuit for receiving said pulse width modulated signal from said pulse generator circuit and for generating in response thereto a pulse width modulated output signal whose duty cycle matches that of said pulse width modulated signal through which energy from a source of energy is delivered to said coil so as to control operation of said solenoid operated valve thereby controlling operation of said brake control apparatus; and
(c) a feedback circuit, disposed between said coil and said pulse generator circuit, for generating said feedback signal thereby enabling said pulse generator circuit to adjust said pulse width modulated signal to compensate for variations in energy supplied by said source of energy.
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Accused Products
Abstract
A pulse width modulated drive circuit drives a solenoid operated valve in response to an input voltage signal from a control apparatus. The solenoid operated valve includes a coil that is energizable in response to energy received from the pulse width modulated drive circuit. The pulse width modulated drive circuit includes a pulse generator stage and an output stage. The pulse generator stage receives the input voltage signal from the control apparatus and a feedback signal from the coil which ultimately combine to form a control voltage in response to which the pulse generator stage generates a pulse width modulated signal whose duty cycle depends on the control voltage. The output stage receives the pulse width modulated signal from the pulse generator stage and generates in response thereto a pulse width modulated output signal across the coil. The pulse width modulated output signal has pulse width generally proportional to the control voltage and carries energy from a source of energy. The pulse width modulated output signal energizes the coil thereby enabling the coil to generate a force generally proportional to the average current carried by the pulse width modulated output signal.
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Citations
20 Claims
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1. A pulse width modulated drive circuit for driving a solenoid operated valve in response to an input voltage signal from a brake control apparatus, said solenoid operated valve including a coil that is energizable in response to energy received from said drive circuit, said drive circuit comprising:
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(a) a pulse generator circuit for receiving said input voltage signal from said brake control apparatus and a feedback signal derived from said coil and for generating in response thereto a pulse width modulated signal whose duty cycle depends thereon; (b) an output circuit for receiving said pulse width modulated signal from said pulse generator circuit and for generating in response thereto a pulse width modulated output signal whose duty cycle matches that of said pulse width modulated signal through which energy from a source of energy is delivered to said coil so as to control operation of said solenoid operated valve thereby controlling operation of said brake control apparatus; and (c) a feedback circuit, disposed between said coil and said pulse generator circuit, for generating said feedback signal thereby enabling said pulse generator circuit to adjust said pulse width modulated signal to compensate for variations in energy supplied by said source of energy. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A pulse width modulated drive circuit for driving a solenoid operated valve in response to an input voltage signal from a brake control apparatus, said solenoid operated valve including a coil that is energizable in response to energy received from said drive circuit, said drive circuit comprising:
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(a) a pulse generating means for receiving said input voltage signal from said brake control apparatus and a feedback signal derived from said coil which ultimately combine to form a control voltage in response to which said pulse generating means generates a pulse width modulated signal whose duty cycle depends thereon; (b) an output means for receiving said pulse width modulated signal from said pulse generating means and for generating in response thereto a pulse width modulated output signal having pulse width generally proportional to said control voltage through which energy from a source of energy energizes said coil thereby enabling said coil to generate a force generally proportional to the average current carried by said pulse width modulated output signal so as to control operation of said solenoid operated valve thereby controlling operation of said brake control apparatus; and (c) a means, disposed between said coil and said pulse generating means, for generating said feedback signal so as to enable said pulse generating means to adjust said pulse width modulated signal to compensate for variations in energy supplied by said source of energy. - View Dependent Claims (17, 18, 19, 20)
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Specification