Patent ID: 7908102

Claim:
A voltage measuring device comprising: a plurality of voltage measuring members respectively provided at blocks composed of series-connected unit cells made of secondary batteries composing an assembled battery for measuring voltages across the unit cells composing the blocks; and a control member for receiving measured results of the voltages across the unit cells via communication with the voltage measuring members, wherein when the voltage measuring members receive a sleep order via communication with the control member, the voltage measuring members enter a sleep mode in which the voltage measuring members stop the communication with the control member, wherein when an awakening signal is inputted to an awakening terminal, the sleep mode is exited, and the voltage measuring members restart the communication with the control member, wherein the voltage measuring member includes: an isolation device to output a high level awakening signal isolated from the control member corresponding to the awakening signal from the control member; a first semiconductor switch having a first control terminal to which the high level awakening signal is inputted from the isolation device, a first terminal connected to an anode of the assembled battery, and a second terminal connected to a cathode of the assembled battery, a junction between said first and second terminals conducting when the high level awakening signal is inputted to the first control terminal; and a plurality of second semiconductor switches provided corresponding to the blocks, wherein the second semiconductor switch has a second control terminal connected to the first terminal of the first semiconductor switch, a third terminal connected to an anode of the corresponding block, and a fourth terminal connected to the awakening terminal, a junction between said third and fourth terminals conducting when the second control terminal is connected to the cathode of the assembled battery.