Electronic interval timing device
First Claim
1. An elapsed-time reminder circuit, comprising:
- (a) a pair of electrolytic timing cells, each having first and second operating states, said timing cells having a relatively low resistance in said first operating state and a relatively high resistance in said second operating state, said timing cells being configured and arranged so as to change state from said first operating state to said second operating state in response to the application thereto for a known time interval of a current having a first polarity, and further to change state from said second operating state to said first operating state in response to the application thereto of a current having a second polarity opposite to said first polarity;
(b) means supplying a current of said first polarity to one of said timing cells when said one timing cell is in said first operating state;
(c) electrical circuit means for detecting when said one timing cell changes state from said first operating state to said second operating state, including means generating an output signal upon detection thereof;
(d) means operative simultaneously with said detecting means for applying a current of said second polarity to the other timing cell when said other timing cell is in said second operating state, and changing the state of said other timing cell to a first operating state such that said other timing cell has been changed to a first operating state when said one timing cell changes state from said first operating state to said second operating state;
(e) indicator means responsive to said output signal for indicating to an operator when said one timing cell changes state from said first operating state to said second operating state and hence, when said known time interval has elapsed; and
(f) means adapted to permit alternating reversal of said pair of timing cells, respectively, between a first connection in said detecting means and a second connection in said applying means.
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Accused Products
Abstract
Reversible, elapse-time indicator utilizing two solid electrolyte cells in which current of one polarity is applied to one cell to cause silver ions to move from the positive electrode to the negative electrode. When all the ions have been removed from the positive electrode after a predetermined specific interval of time, the cell resistance increases to trigger an alarm such as a lamp. While the first cell is timing out, the second cell is being charged from a zero time value by a current of an opposite polarity equal to the time begun within the first cell. When the time interval has elapsed, the cells are reversed so that the second cell now becomes the timing device and the first cell is being recharged.
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Citations
14 Claims
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1. An elapsed-time reminder circuit, comprising:
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(a) a pair of electrolytic timing cells, each having first and second operating states, said timing cells having a relatively low resistance in said first operating state and a relatively high resistance in said second operating state, said timing cells being configured and arranged so as to change state from said first operating state to said second operating state in response to the application thereto for a known time interval of a current having a first polarity, and further to change state from said second operating state to said first operating state in response to the application thereto of a current having a second polarity opposite to said first polarity; (b) means supplying a current of said first polarity to one of said timing cells when said one timing cell is in said first operating state; (c) electrical circuit means for detecting when said one timing cell changes state from said first operating state to said second operating state, including means generating an output signal upon detection thereof; (d) means operative simultaneously with said detecting means for applying a current of said second polarity to the other timing cell when said other timing cell is in said second operating state, and changing the state of said other timing cell to a first operating state such that said other timing cell has been changed to a first operating state when said one timing cell changes state from said first operating state to said second operating state; (e) indicator means responsive to said output signal for indicating to an operator when said one timing cell changes state from said first operating state to said second operating state and hence, when said known time interval has elapsed; and (f) means adapted to permit alternating reversal of said pair of timing cells, respectively, between a first connection in said detecting means and a second connection in said applying means. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An elapsed-time reminder circuit, comprising:
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(a) electrolytic timing means having first and second operating states, said timing means having a relatively low resistance in said first operating state and a relatively high resistance in said second operating state, said timing means being configured and arranged so as to change state from said first operating state to said second operating state in response to the application thereto for a known interval of a current having a first polarity and further operative to change state from said second operating state to said first operating state in a response to the application thereto of a current having a second polarity opposite to said first polarity; (b) means supplying a current of said first polarity to said timing means when said timing means is in said first operating state; (c) electrical circuit means for detecting when said timing means changes state from said first operating state to said second operating state, including means generating an output signal upon detection thereof; (d) means applying a current of said second polarity to said timing means when said timing means is in said second operating state, thereby changing the state of said timing means to said first operating state; (e) indicator means responsive to said output signal for indicating to an operator when said timing means changes state from said first operating state to said second operating state and hence, when said known time interval has elapsed; and (f) means adapted to permit alternate connection of said timing means in said detecting means when said timing means is in said first operating state and in said applying means when said timing means is in said second operating state. - View Dependent Claims (9, 10, 11, 12, 13)
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14. An elapsed-time service indicator for installation in motor vehicles for indicating when servicing of the vehicle is required, comprising:
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(a) a pair of electrolytic timing cells, each having first and second operating states, said timing cells having a relatively low resistance in said first operating state and a relatively high resistance in said second operating state, said timing cells being configured and arranged so as to change state from said first operating state to said second operating state in response to the application thereto for a known time interval of a current having a first polarity, and further to change state from said second operating state to said first operating state in response to the application of a current having a second polarity opposite from said first polarity; (b) battery operated means located in the vehicle for supplying a current of said first polarity to one of said timing cells, when said one timing cell is in said first operating state, said supplying means thus operating substantially only when said motor vehicle is in operation; (c) electrical circuit means for detecting when said one timing cell changes state from said first operating state to said second operating state in response to application of the current of said first polarity thereto, said electrical circuit means including means generating an output signal upon detection that said one timing cell has changed state from said first operating state to said second operating state; (d) battery operated means operative simultaneously with said detecting means to apply a current of said second polarity to the other timing cell when said other timing cell is in said second operating state, thereby changing the state of the other timing cell to said first operating state over the time interval said one timing cell is in said first operating state such that said other timing cell is in said first operating state when said one timing cell changes state from said first operating state to said second operating state; (e) indicator means energized by said output signal for indicating to the operator of the motor vehicle when said one timing cell changes state from said first operating state to said second operating state and hence, when said known time interval has elapsed and servicing of the vehicle is required; and (f) means adapted to permit reversal of said pair of timing cells, respectively, between a first connection in said detecting means and a second connection in said applying means.
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Specification