Patent ID: 6570746
Filing Date: 2003-05-27
Classification: H02J

Abstract:
An apparatus for protecting a charger system when a power source is deactivated, wherein the charger system is arranged to charge a battery when the power source is activated, comprising:a primary input that is arranged to selectively receive energy from the power source; a switching circuit that is arranged to selectively couple the power source to the primary input when enabled; a primary charge-path circuit that is arranged to selectively couple power from the primary input to the battery when enabled, such that the battery is selectively charged by a primary charging current; a controlled clamp circuit that is coupled to the primary input, wherein the controlled clamp is arranged to selectively limit a voltage associated with the primary input when enabled; and a control circuit that is arranged to enable the controlled clamp circuit when the power source is deactivated, enable the primary charge-path circuit when the power source is activated, and enable the switching circuit when the power source is activated such that the controlled clamp provides a voltage limit to the primary input, whereby the controlled clamp protects the charger system from a short circuit condition in the switching circuit.