Patent ID: 7872447
Filing Date: 2011-01-18
Classification: H02J

Abstract:
1. An electrical storage apparatus connected between a main power supply and a load, the electrical storage apparatus comprising: a first bypass FET (Field Effect Transistor) and a bypass diode connected in series between the main power supply and the load; an electric charger circuit connected to the main power supply; an electric storage device connected to the electric charger circuit; a first main path FET (Field Effect Transistor) and a second main path FET (Field Effect Transistor) connected in series between the electric storage device and the load; a voltage detector circuit that detects a voltage (Vb) of the main power supply, a voltage (Va) of the load, a voltage (Vc) at a connection point between the first bypass FET and the bypass diode, and a voltage (Vd) at a connection point between the first main path FET and the second main path FET; and a controller connected to the first bypass FET, the first main path FET, the second main path FET, the electric charger circuit and the voltage detector circuit, wherein the bypass diode has an anode connected to the first bypass FET and a cathode connected to the load, wherein the controller judges that the first bypass FET suffers an open-circuit failure in either one of a case where the voltage (Va) of the load detected by the voltage detector circuit is equal to or smaller than a first threshold value Vth wherein the controller judges that the bypass diode suffers an open-circuit failure if the voltage (Va) of the load is equal to or smaller than a third threshold value Vth wherein the controller judges that the second main path FET suffers an open-circuit failure if the voltage (Va) of the load is equal to or smaller than a sixth threshold value Vth wherein the controller judges that the second main path FET suffers an open-circuit failure if the voltage (Vd) at the connection point between the first main path FET and the second main path FET is equal to or smaller than a seventh threshold value Vth wherein the controller judges that the first bypass FET suffers a short-circuit failure if the voltage (Vc) at the connection point between the first bypass FET and the bypass diode is equal to or larger than an eighth threshold value Vth wherein the controller judges that the bypass diode suffers a short-circuit failure if the voltage (Vc) at the connection point between the first bypass FET and the bypass diode is equal to or larger than a ninth threshold value Vth