Patent ID: 6411483
Filing Date: 2002-06-25
Classification: H02M

Abstract:
In a power conditioning apparatus utilizing a switching regulator, the apparatus having a reference voltage, a means for producing an indicating voltage corresponding to the magnitude of the input current and means for disabling the apparatus, an overcurrent protection circuit comprising:a comparison means for comparing the indicating voltage to a signal corresponding to the reference voltage and outputting a control signal to the disabling means when the indicating voltage exceeds a predetermined voltage threshold corresponding to a maximum current trip setpoint; a switching means for reducing the reference voltage signal received by the comparison means in response to the presence of the control signal from the comparison means, the reference voltage signal reduced to a predetermined voltage threshold to ensure the comparison means continues to output a control signal to the disabling means regardless of the forthcoming drop in the indicating voltage; and a timeout means for maintaining the control signal received by the switching means for only a predetermined time period such that the switching means eventually restores the reference voltage signal sent to the comparison means to its pre-reduction state, thereby allowing the comparison means to discontinue outputting the control signal to the disabling means if the indicating voltage is below the predetermined voltage threshold corresponding to the maximum current trip setpoint.