Patent ID: 7786619
Filing Date: 2010-08-31
Classification: H02J

Abstract:
1. A battery backup apparatus connected with a movable barrier operator which includes a DC power supply, the battery backup apparatus comprising: a battery; a battery charging circuit coupled to the battery; and a conduction path between the battery and the movable barrier operator, the conduction path including a unidirectional isolation device, the battery backup apparatus configured to connect to a plug of the movable barrier operator, and the battery charging circuit configured to receive a DC voltage from the DC power supply located within the movable barrier operator through the plug and an impedance element in parallel with a second unidirectional isolation device disposed in the movable barrier operator to charge the battery when the DC voltage from the DC voltage supply exceeds a predetermined voltage, the battery backup apparatus further configured to provide a battery backup voltage through the second unidirectional isolation device, the plug, and the unidirectional isolation device, the battery backup voltage being provided from the battery when mains voltage to the movable barrier operator fails.