Compensation circuit for current peaking reduction in notification appliances

#1. Field of the Invention

#Embodiments of the present disclosure relate to compensation circuits for current peaking reduction. More particularly, the present disclosure relates to compensation circuits for reducing current peaking in current controlled pulse-width modulation (PWM) circuits for notification appliances such as those used in fire alarm systems.

#2. Discussion of Related Art

#The accompanying drawings illustrate preferred embodiments of the disclosed method so far devised for the practical application of the principles thereof, and in which:

#FIG. 1A illustrates a block diagram of an exemplary notification appliance.

#FIG. 1B illustrates a block diagram of the boost circuit shown in FIG. 1A used to drive a notification appliance having a Xenon Flash tube.

#The present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention, however, may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, like numbers refer to like elements throughout.

#Various embodiments may be generally directed to reducing current peaking in notification appliances. In one embodiment, for example, a current peaking compensation circuit may comprise two or more transistors and one or more capacitors configured to reduce a start-up frequency of a pulse-width modulated signal during a first time period and to add a time constant decaying voltage across a resistor divider network to increase a reference voltage during the first time period. In this manner, current peaking for notification appliances may be reduced and the notification appliances may operate using substantially flat, scalable, constant or otherwise predictable current. Other embodiments may be described and claimed.

#FIG. 1A is a functional block diagram of a notification appliance 10 including an inrush control 12, a boost converter 15, an energy storage capacitor 16, and an optical output element or flash tube 20. The optical element may also be referred to herein as a load configured to provide the necessary candela for visual notification. An input voltage is applied to the inrush control 12 as well as to trigger circuits 11. The output of the inrush control 12 is supplied to low voltage regulator circuit 13 that supplies an input to boost converter 15.