Flying capacitor type battery voltage detector
First Claim
1. A flying capacitor type battery voltage detector, comprising:
- a circuit substrate having a front surface and a back surface opposite to the front surface in its thickness direction;
a plurality of potential detecting substrate surface lines which are each disposed on the front or back surface of the circuit substrate, the potential detecting substrate surface lines being connected with a plurality of terminals of cells or groups of cells of a battery pack, respectively;
a first floating line disposed on the front or back surface of the circuit substrate;
a second floating line disposed on the front or back surface of the circuit substrate;
a multiplexer including a first portion disposed on the front surface of the circuit substrate and a second portion disposed on the back surface of the circuit substrate such that the second portion substantially lies over the first portion through the circuit substrate in the thickness direction of the circuit substrate, the multiplexer sequentially connecting the potential detecting substrate surface lines of each of pairs with the first and second floating lines, respectively, to connect the terminals of one of pairs corresponding to the potential detecting substrate surface lines of the pair with the first and second floating lines, respectively;
a flying capacitor, connected with the first and second floating lines, which holds an electric energy transmitted from the terminals of the corresponding pair through the potential detecting substrate surface lines of the pair and the first and second floating lines; and
an analog switch which is maintained in an off state when the potential detecting substrate surface lines of the pair are, respectively, connected with the first and second floating lines by the multiplexer, and which is turned on when the potential detecting substrate surface lines of the pair are disconnected from the first and second floating lines, the electric energy of the flying capacitor being outputted through the analog switch when turned on in a form of a signal as a function of an output voltage appearing between the terminals of the corresponding pair.
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Accused Products
Abstract
In a flying capacitor type battery voltage detector on a circuit substrate, a large number of photo MOS switches having performance highly depending from temperature are dividedly disposed on front and back surfaces of the circuit substrate such that the photo MOS switches of the back surface are lying over the photo MOS switches of the front surface. Each of pairs of photo MOS switches connects a pair of surface lines with first and second floating lines to transmit an output voltage of each cell of a battery pack connected with the surface lines to a differential amplifier through a flying capacitor connected with the floating lines. Because of the division of the photo MOS switches on the surfaces of the circuit substrate, temperatures of the photo MOS switches have less dispersion, and an S/N ratio of each signal indicating the output voltage can be improved.
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Citations
13 Claims
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1. A flying capacitor type battery voltage detector, comprising:
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a circuit substrate having a front surface and a back surface opposite to the front surface in its thickness direction;
a plurality of potential detecting substrate surface lines which are each disposed on the front or back surface of the circuit substrate, the potential detecting substrate surface lines being connected with a plurality of terminals of cells or groups of cells of a battery pack, respectively;
a first floating line disposed on the front or back surface of the circuit substrate;
a second floating line disposed on the front or back surface of the circuit substrate;
a multiplexer including a first portion disposed on the front surface of the circuit substrate and a second portion disposed on the back surface of the circuit substrate such that the second portion substantially lies over the first portion through the circuit substrate in the thickness direction of the circuit substrate, the multiplexer sequentially connecting the potential detecting substrate surface lines of each of pairs with the first and second floating lines, respectively, to connect the terminals of one of pairs corresponding to the potential detecting substrate surface lines of the pair with the first and second floating lines, respectively;
a flying capacitor, connected with the first and second floating lines, which holds an electric energy transmitted from the terminals of the corresponding pair through the potential detecting substrate surface lines of the pair and the first and second floating lines; and
an analog switch which is maintained in an off state when the potential detecting substrate surface lines of the pair are, respectively, connected with the first and second floating lines by the multiplexer, and which is turned on when the potential detecting substrate surface lines of the pair are disconnected from the first and second floating lines, the electric energy of the flying capacitor being outputted through the analog switch when turned on in a form of a signal as a function of an output voltage appearing between the terminals of the corresponding pair. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A flying capacitor type battery voltage detector, comprising:
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a circuit substrate having a front surface and a back surface opposite to the front surface in its thickness direction;
a plurality of potential detecting substrate surface lines which are each disposed on the front or back surface of the circuit substrate, the potential detecting substrate surface lines being connected with a plurality of terminals of cells or groups of cells of a battery pack, respectively;
a first floating line disposed on the front or back surface of the circuit substrate;
a second floating line disposed on the front or back surface of the circuit substrate;
a multiplexer, having a plurality of photo MOS switches which are each disposed on the front or back surface of the circuit substrate and connects one of the potential detecting substrate surface lines with the first or second floating line such that a part of the photo MOS switches disposed on the back surface of the circuit substrate are substantially lying over the remaining part of the photo MOS switches disposed on the front surface of the circuit substrate through the circuit substrate in the thickness direction, the multiplexer sequentially turning on the photo MOS switches of each of pairs to connect the terminals of one of pairs corresponding to the photo MOS switches of the pair with the first and second floating lines through the potential detecting substrate surface lines of one of pairs corresponding to the photo MOS switches of the pair, respectively;
a flying capacitor, connected with the first and second floating lines, which holds an electric energy transmitted from the terminals of the corresponding pair through the potential detecting substrate surface lines of the corresponding pair, the photo MOS switches of the pair and the first and second floating lines; and
an analog switch which is maintained in an off state when the multiplexer turns on the photo MOS switches of the pair, and which is turned on when the multiplexer turns off all the photo MOS switches, the electric energy of the flying capacitor being outputted through the analog switch when turned on in a form of a signal as a function of an output voltage appearing between the terminals of the corresponding pair.
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Specification