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Pulse width modulated drive for an infinitely variable solenoid operated brake cylinder pressure control valve

  • US 5,815,362 A
  • Filed: 12/04/1996
  • Issued: 09/29/1998
  • Est. Priority Date: 12/04/1996
  • Status: Expired due to Fees
First Claim
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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:

  • (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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