Digital battery capacity warning device

Claim 2

A voltage monitor for sensing the output voltage of a voltage source and producing an indication when said output voltage falls below a threshold voltage, said voltage monitor comprising: voltage sensing means for sensing said output voltage and including means for comparing said output voltage with said threshold voltage and generating an output when said output voltage is less than said threshold voltage; status storage means coupled to said voltage sensing means for storing said output and generating an accumulated status; comparator means for comparing said accumulated status with a first predetermined number when said output voltage has been sensed a second predetermined number of times; and output means for providing said indication when said accumulated status is equal to or greater than said first predetermined number.

Claim 3

A voltage monitor as defined in claim 1 wherein said status storage means comprises a plurality of storage means for storing a like plurality of said first comparator outputs.

Claim 4

A voltage monitor as defined in claim 2, wherein each of said plurality of storage means has an associated order, said order being from highest to lowest, and wherein said status storage means is responsive to a clock signal for discarding the contents of the highest-ordered of said storage means, sequentially moving the contents of each of said storage means to the next highest-ordered storage means, and storing said first comparator output in the lowest-ordered of said storage means.

Claim 5

A voltage monitor as defined in claim 3 further comprising a timing means for generating said clock signal.

Claim 6

A voltage monitor as defined in claim 3 wherein said status storage means comprises a shift register.

Claim 7

A voltage monitor as defined in claim 1 further comprising a threshold generating means for generating said threshold voltage.

Claim 8

A voltage monitor as defined in claim 1 wherein said means for comparing comprises a voltage comparator.

Claim 9

A voltage monitor as defined in claim 1 wherein said comparator means comprises a voltage comparator.

Claim 10

A voltage monitor as defined in claim 1 wherein said output means includes a field effect transistor.

Claim 11

A battery voltage monitor for sensing a depletable battery voltage and producing an indication when said battery voltage falls below a first threshold voltage, said battery voltage monitor comprising: threshold generating means for generating said first threshold voltage and a second threshold voltage; and voltage sensing means for sensing said battery voltage, including means for comparing said battery voltage with said first threshold voltage and generating an output when said battery voltage is less than said first threshold voltage; status storage means coupled to said voltage sensing means for storing said output and generating an accumulated battery status, said accumulated battery status comprising a voltage representing the number of times said battery voltage was sensed to be less than said first threshold voltage; comparator means for comparing said accumulated battery status with said second threshold voltage and generating a comparator output when said accumulated battery status is greater than said second threshold voltage; output means responsive to said comparator output for providing said indication; power supply means for generating a regulated supply voltage level and coupled to said means for comparing, said comparator means, said status storage means and said threshold generating means.

Claim 12

A battery voltage monitor for sensing a depletable battery voltage and producing an indication when said battery voltage falls below a first threshold voltage, said battery voltage monitor comprising: threshold generating means for generating said first threshold voltage and a second threshold voltage; and voltage sensing means for sensing said battery voltage, including means for comparing said battery voltage with said first threshold voltage and generating an output when said battery voltage is less than said first threshold voltage; status storage means coupled to said voltage sensing means for storing said output and generating an accumulated battery status, said accumulated battery status comprising a voltage representing the number of times said battery voltage was sensed to be less than said first threshold voltage; comparator means for comparing said accumulated battery status with said second threshold voltage and generating a comparator output when said accumulated battery status is greater than said second threshold voltage; output means responsive to said comparator output for providing said indication; power supply means for generating a regulated supply voltage level and coupled to said means for comparing, said comparator means, said status storage means and said threshold generating means.

Claim 13

A battery voltage monitor as defined in claim 10 wherein said status storage mean comprises a plurality of storage means for storing a like plurality of said first comparator outputs in response to a clock signal.

Claim 14

A battery voltage monitor as defined in claim 11 further comprising a timing means for generating said clock signal.

Claim 15

A battery voltage monitor as defined in claim 12 wherein said status storage means comprises a shift register.

Claim 16

A battery voltage monitor as defined in claim 11 wherein said means for comparing is a voltage comparator.

Claim 17

A battery voltage monitor as defined in claim 14 wherein said comparator means is a voltage comparator.

Claim 18

A battery voltage monitor as defined in claim 10 wherein said output means is a field effect transistor.

Claim 23

A method as defined in claim 18 including the further step of generating a clock signal to clock said periodic storing of said output.

Claim 24

A method as defined in claim 18 including the further step of maintaining said first threshold voltage and said second threshold voltage constant against variations in supply voltage and temperature.

Claim 25

A voltage monitor for sensing a voltage source output voltage and producing an indication upon an abnormal condition of said voltage source output voltage, said voltage monitor comprising: voltage sensing means for sensing said voltage source output voltage; first comparator means for comparing said voltage source output voltage with a threshold voltage and generating a first output when said voltage source output voltage is less than said threshold voltage; status storage means coupled to said voltage sensing means for storing a preselected number of said first outputs and generating an accumulated value; and second comparator means coupled to said status storage means for comparing said accumulated value with a predetermined value and generating said indication when said accumulated value is equal to or greater than said predetermined value.

Claim 26

A voltage monitor for sensing a voltage source output voltage and producing an indication upon an abnormal condition of said voltage source output voltage, said voltage monitor comprising: voltage sensing means for sensing said voltage source output voltage; first comparator means for comparing said voltage source output voltage with a threshold voltage and generating a first output when said voltage source output voltage is less than said threshold voltage; status storage means coupled to said voltage sensing means for storing a preselected number of said first outputs and generating an accumulated value; and second comparator means coupled to said status storage means for comparing said accumulated value with a predetermined value and generating said indication when said accumulated value is equal to or greater than said predetermined value.

Claim 27

A voltage monitor as define din claim 21 wherein said status storage means comprises a plurality of sub-storage means for storing a like plurality of said first outputs.

Claim 28

A voltage monitor as defined in claim 22, wherein each of said plurality of sub-storage means has an associated order, said associated order being from highest to lowest, and wherein said status storage means is responsive to a clock signal for discarding the contents of the highest-ordered of said sub-storage means, sequentially moving the contents of each of said sub-storage means to the next highest-ordered said sub-storage means, and storing said first output in the lowest-ordered of said sub-storage means.

Claim 29

A voltage monitor as defined in claim 23 further comprising timing means for generating said clock signal.

Claim 30

A voltage monitor as defined in claim 23 wherein said status storage means comprises a shift register.

Claim 31

A voltage monitor as defined in claim 21 further comprising a threshold generating means for generating said threshold voltage.

Claim 32

A voltage monitor as defined in claim 21 wherein said second comparator means comprises a voltage comparator.

Claim 33

A voltage monitor as defined in claim 21 wherein said second comparator means comprises a voltage comparator.

Claim 34

A voltage monitor as defined in claim 21 wherein said second comparator means includes one of: a filed effect transistor and a bipolar transistor.

Claim 35

A battery voltage monitor for sensing a depletable battery voltage and producing an indication when said depletable battery voltage signifies an abnormal condition, said battery voltage monitor comprising: threshold generating means for generating a first threshold voltage and a second threshold voltage; voltage sensing means coupled to said threshold generating means for sensing said depletable battery voltage;; first comparator means coupled to said voltage sensing means for comparing said depletable battery voltage with said first threshold voltage and generating a first output when said depletable battery voltage is less than said first threshold voltage; status storage means coupled to said first comparator means for storing a preselected number of said first outputs and generating an accumulated battery value; second comparator means coupled to said status storage means and said threshold generating means for comparing said accumulated battery value with said second threshold voltage and generating said indication when said accumulated battery value is greater than said second threshold voltage; and power supply means for generating a regulated supply voltage level and coupled to said first comparator means, said second comparator means, said status storage means and said threshold generating means.

Claim 36

A battery voltage monitor for sensing a depletable battery voltage and producing an indication when said depletable battery voltage signifies an abnormal condition, said battery voltage monitor comprising: threshold generating means for generating a first threshold voltage and a second threshold voltage; voltage sensing means coupled to said threshold generating means for sensing said depletable battery voltage;; first comparator means coupled to said voltage sensing means for comparing said depletable battery voltage with said first threshold voltage and generating a first output when said depletable battery voltage is less than said first threshold voltage; status storage means coupled to said first comparator means for storing a preselected number of said first outputs and generating an accumulated battery value; second comparator means coupled to said status storage means and said threshold generating means for comparing said accumulated battery value with said second threshold voltage and generating said indication when said accumulated battery value is greater than said second threshold voltage; and power supply means for generating a regulated supply voltage level and coupled to said first comparator means, said second comparator means, said status storage means and said threshold generating means.

Claim 37

A battery voltage monitor as defined in claim 30 wherein said status storage means comprises a plurality of sub-storage means for storing a like plurality of said first outputs in response to a clock signal.

Claim 38

A battery voltage monitor as defined in claim 31 further comprising a timing means for generating said clock signal.

Claim 39

A battery voltage monitor as defined in claim 32 wherein said status storage means comprises a shift register.

Claim 40

A battery voltage monitor as defined in claim 31 wherein said first comparator means is a voltage comparator.

Claim 41

A battery voltage monitor as defined in claim 34 wherein said second comparator means is a voltage comparator.

Claim 46

A method as defined in claim 37 including a further step of generating a clock signal to clock said periodic storing of said first output.

Claim 47

A method as defined in claim 37 including the further step of maintaining said first threshold voltage and said second threshold voltage constant against variations in supply voltage and temperature.