Patents Assigned to BKL, Inc.
  • Electronluminescent lamp inverter
    Patent number: 5686797
    Abstract: A circuit for providing AC power to an electroluminescent lamp powered by a battery comprises a high frequency oscillator through a control to drive a fly back voltage regulator comprising an inductor powered by a relatively low battery voltage and coupled to ground through a switching transistor. A capacitor coupled to the inductor through a diode is charged by the repetitive charge and discharge of the inductor when the transistor is switched ON and OFF at high frequency by the high frequency oscillator. The charge in the capacitor is dithered about a high DC voltage, such as 100 VDC, by sensing the charged voltage for periodically turning the transistor ON and OFF accordingly. A bridge circuit receives two pairs of like lower frequency square wave pulse signals of opposite polarity from a low frequency oscillator.
    Type: Grant
    Filed: October 27, 1995
    Date of Patent: November 11, 1997
    Assignee: BKL, Inc.
    Inventor: Stephen J. Sanderson
  • Drive circuit for electroluminescent lamp
    Patent number: 5463283
    Abstract: A circuit for providing AC power to an electroluminescent lamp powered by a battery comprises a high frequency oscillator through a control to drive a fly back voltage regulator comprising an inductor powered by a relatively low battery voltage and coupled to ground through a switching transistor. A capacitor coupled to the inductor through a diode is charged by the repetitive charge and discharge of the inductor when the transistor is switched ON and OFF at high frequency by the high frequency oscillator. The charge in the capacitor is dithered about a high DC voltage, such as 100 VDC, by sensing the charged voltage for periodically turning the transistor ON and OFF accordingly. A bridge circuit receives two pairs of like lower frequency square wave pulse signals of opposite polarity from a low frequency oscillator.
    Type: Grant
    Filed: May 24, 1994
    Date of Patent: October 31, 1995
    Assignee: BKL, Inc.
    Inventor: Stephen J. Sanderson
  • Method of making an improved electroluminescent device
    Patent number: 5454892
    Abstract: An electroluminescent device in which water is an essential component. Water is incorporated into the encapsulated phosphor-binder and the dielectric binder to provide a device in which brightness and longevity are enhanced.
    Type: Grant
    Filed: April 1, 1994
    Date of Patent: October 3, 1995
    Assignee: BKL, Inc.
    Inventors: Donald R. Kardon, Charles H. Moore, Douglas S. Bush
  • Electroluminescent device
    Patent number: 5352951
    Abstract: An electroluminescent device in which water is an essential component. Water is incorporated into the encapsulated phosphor-binder and the dielectric binder to provide a device in which brightness and longevity are enhanced.
    Type: Grant
    Filed: June 3, 1991
    Date of Patent: October 4, 1994
    Assignee: BKL, Inc.
    Inventors: Donald R. Kardon, Charles H. Moore, Douglas S. Bush