1. A protection circuit, comprising:
a first terminal;
a second terminal;
a current limiting device coupled to the first terminal;
a solid state relay having switch terminals coupled in series with the current limiting device between the first terminal and the second terminal, the solid state relay having a control terminal and being configured to selectively decouple the first and second switch terminals from each other responsive to a control signal applied to the control terminal;
a detection circuit coupled to the solid state relay and the first terminal and being configured to detect a voltage applied to the first terminal having a magnitude that is greater than a specific value, the detection circuit being configured to apply the control signal to the solid state relay responsive to detecting the voltage having a magnitude greater than the specific value; and
an electromechanical relay having a relay contact switch coupled in series with the solid state relay between the first and second terminals, the electromechanical relay having a relay coil coupled to the detection circuit, the electromechanical relay being configured to automatically open the relay contact switch in response to the detection circuit detecting the voltage having a magnitude greater than the specific value.
2. The protection circuit of claim 1 wherein the current limiting device comprises at least one depletion mode field effect transistor.
3. The protection circuit of claim 2 wherein the current limiting device comprises:
a first depletion mode field effect transistor having a drain coupled to the first terminal, a source coupled to the solid state relay, and a gate; and
a second depletion mode field effect transistor having a drain coupled to the second terminal, a source coupled to the solid state relay and to the gate of the first depletion mode field effect transistor, and a gate coupled to the source of the source of the first depletion mode field effect transistor.
4. The protection circuit of claim 1 wherein the solid state relay comprises:
a light-emitting diode coupled to the control terminal of the solid state relay; and
an opto-transistor optically coupled to the light-emitting diode, the opto-transistor being coupled between the switch terminals of the solid state relay.
5. The protection circuit of claim 1 wherein the detection circuit comprises a voltage detector coupled to the second terminal and configured to detect a voltage larger than a particular level, the voltage detector being configured to apply the control signal to the solid state relay to decouple the first and second switch terminals from each other responsive to detecting a voltage larger than the particular level.
6. The protection circuit of claim 1 wherein the detection circuit comprises a circuit extending between a first connection to the first terminal and a second connection to the first terminal, the second connection being separated from the first connection by the current limiting device.
7. The protection circuit of claim 6 wherein the solid state relay comprises a first solid state relay, and wherein the detection circuit comprises a second solid state relay having a pair of control terminals coupled between the first connection and the second connection, the second solid state relay further having a switch terminal coupled to the first solid state relay and configured to apply the control signal to the solid state relay responsive to a current flowing between the first connection and the second connection.
8. The protection circuit of claim 7 wherein the second solid state relay comprises:
a light-emitting diode coupled between the control terminals of the second solid state relay; and
an opto transistor optically coupled to the light-emitting diode of the second solid state relay and electrically coupled to the control terminal of the first solid state relay.
9. The protection circuit of claim 1 wherein the specific voltage that the detection circuit is configured to detect is dynamically adjustable by programming the detection circuit with different voltage detection levels.
10. A protection circuit, comprising:
a first terminal;
a second terminal;
a current limiting device coupled to the first terminal;
a solid state relay having switch terminals coupled in series with the current limiting device between the first terminal and the second terminal, the solid state relay having a control terminal and being configured to selectively decouple the first and second switch terminals from each other responsive to a control signal applied to the control terminal;
a detection circuit coupled to the solid state relay and the first terminal and being configured to detect a voltage applied to the first terminal having a magnitude that is greater than a specific value, the detection circuit being configured to apply the control signal to the solid state relay responsive to detecting the voltage having a magnitude greater than the specific value, wherein the detection circuit comprises a circuit extending between a first connection to the first terminal and a second connection to the first terminal, the second connection being separated from the first connection by the current limiting device, and wherein the detection circuit further comprises:
a first light-emitting diode having a cathode coupled to the first connection and an anode coupled to the second connection;
a second light-emitting diode having an anode coupled to the first connection and a cathode coupled to the second connection;
a first opto-transistor optically coupled to the first light-emitting diode, the first opto-transistor being coupled to the control input of the first solid state relay; and
a second opto-transistor optically coupled to the second light-emitting diode, the second opto-transistor being coupled to the control input of the first solid state relay.
11. The protection circuit of claim 10 wherein the first and second opto-transistors are coupled to the control input of the solid state relay through a circuit, comprising:
a comparator having an input coupled to the first and second opto-transistors and an output; and
a latch having a latch input coupled to the output of the comparator and a latch output coupled to the control input of the solid state relay.
12. A system, comprising:
an electronic device having a device terminal;
a system terminal;
a current limiting device coupling the system terminal to the device terminal;
a solid state relay having a first opto-transistor coupled between the system terminal and the device terminal in series with the current limiting device and a first light-emitting diode optically coupled to the first opto-transistor;
a detection circuit configured to detect a voltage applied to the system terminal having a magnitude that is greater than a specific value, the detection circuit being coupled to apply a voltage to the first light-emitting diode to cause current to flow through the first light-emitting diode responsive to detecting a voltage applied to the system terminal having a magnitude that is greater than a specific value; and
an electromechanical relay having a relay contact switch coupled in series with the solid state relay between the first and second terminals and a relay coil coupled to the detection circuit, the electromechanical relay being configured to automatically open the relay contact switch in response to the detection circuit detecting the voltage having a magnitude greater than the specific value.
13. The system of claim 12 wherein the current limiting device comprises:
a first depletion mode field effect transistor having a drain coupled to the system terminal, a source coupled to a first terminal of the opto-transistor, and a gate; and
a second depletion mode field effect transistor having a drain coupled to the device terminal, a source coupled to the gate of the first depletion mode field effect transistor and to a second terminal of the opto-transistor that is different from the first terminal of the opto-transistor, and a gate coupled to the source of the first depletion mode field effect transistor.
14. The system of claim 12 wherein the electronic device comprises an electrical testing device configured to selectively couple a current or voltage to the device terminal having a plurality of different magnitudes, and wherein the detection circuit is configured to be programmable to adjust the specific voltage that the detection circuit is configured to detect as a function of the current or voltage that the electronic device couples to the device terminal.
15. The system of claim 12, further comprising an electromechanical relay having a relay contact switch coupled between the system terminal and the device terminal, the electromechanical relay further having a relay coil coupled to the detection circuit to receive a signal from the detection circuit responsive to detecting the voltage having a magnitude greater than the specific value to open the relay contact switch.
16. A system, comprising:
an electronic device having a device terminal;
a system terminal;
a current limiting device coupling the system terminal to the device terminal;
a first opto-transistor coupled between the system terminal and the device terminal in series with the current limiting device;
a first light-emitting diode optically coupled to the first opto-transistor;
a detection circuit configured to detect a voltage applied to the system terminal having a magnitude that is greater than a specific value, the detection circuit being coupled to apply a voltage to the first light-emitting diode to cause current to flow through the first light-emitting diode responsive to detecting a voltage applied to the system terminal having a magnitude that is greater than a specific value, wherein the detection circuit comprises:
a second light-emitting diode having a cathode coupled to a first connection to the system terminal and having an anode coupled to a second connection to the system terminal, the second connection being separated from the first connection by the current limiting device;
a third light-emitting diode having an anode coupled to the first connection and a cathode coupled to the second connection;
a second opto-transistor optically coupled to the second light-emitting diode, the second opto-transistor being coupled to the first light-emitting diode; and
a third opto-transistor optically coupled to the third light-emitting diode, the third opto-transistor being coupled to the first light-emitting diode.
17. The system of claim 16 wherein the second and third opto-transistors are coupled to the first light-emitting diode through a circuit, comprising:
a comparator having an input coupled to the second and third opto-transistors and an output; and
a latch having a latch input coupled to the output of the comparator and a latch output coupled to the first light-emitting diode.
18. A method of protecting an electronic device from a voltage applied to a terminal, comprising:
coupling the terminal to the electronic device thorough a solid state relay having an opto-transistor;
optically coupling the opto-transistor to a light-emitting diode;
detecting a voltage applied to the terminal having a magnitude that is greater than a specific value;
limiting the flow of current from the terminal and the electronic device; and
in response to detecting the voltage having a magnitude that is greater than a specific value, interrupting an electrical connection between the terminal and the electronic device by causing current to flow though the light-emitting diode and automatically actuating an electromechanical relay contact switch in series with the terminal and the electronic device to open the contact switch.
19. The method of claim 18 wherein the act of detecting the voltage having a magnitude that is greater than a specific value comprises detecting a voltage differential in a path through which the terminal is coupled to the electronic device.
20. The method of claim 18 wherein the act of limiting the flow of current from the terminal and the electronic device comprises coupling the terminal to the electronic device by at least one depletion mode field effect transistor.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A terminal for managing parts inventory prepared for more than one unit of operating equipment, the terminal comprising a storage section and a control section;
the storage section storing failure-predicted pattern information including information for specifying;
a failure-predicted pattern which is a pattern of a value obtained from a sensor monitoring a state of the operating equipment and indicates that a failure is predicted as to a part used in the operating equipment, the part having a possibility of failure occurrence when the failure-predicted pattern appears, and a first failure rate indicating a probability that the part fails to operate properly when the failure is predicted, and
the storage section further storing operating equipment information including information for specifying; the operating equipment, the part used in the operating equipment, a quantity of the part used in the operating equipment, and a second failure rate indicating the probability that the part fails to operate properly when no failure is predicted, wherein,
the control section performs;
a process for specifying from the failure-predicted pattern information, a failure-predicted pattern which is associated with a pattern of the value, being determined as abnormal when obtained from the sensor which monitors the state of the operating equipment,
a process for specifying the part having a possibility of malfunction as a failure-predicted part according to the failure-predicted pattern being specified,
a process for specifying as a failure-predicted quantity from the operating equipment information, being a quantity of the failure-predicted part used in the operating equipment that has the value obtained from the sensor being determined as abnormal,
a process for specifying as a no-failure-predicted quantity from the operating equipment information, being the quantity of the part of the same sort as the failure-predicted part, used in operating equipment other than the operating equipment that has the value obtained from the sensor being determined as abnormal, among at least one unit of the operating equipment,
a process for calculating a first required quantity that is required as an inventory, when the part corresponding to the failure-predicted quantity fails to operate properly at the first failure rate,
a process for calculating a second required quantity that is required as the inventory, when the part corresponding to the no-failure-predicted quantity fails to operate properly at the second failure rate, and
a process for calculating a required inventory quantity of the part that is of the same sort as the failure-predicted part, by adding the first required quantity and the second required quantity.
2. The terminal according to claim 1, wherein,
the control section calculates the first required quantity according to a Poisson distribution, in such a manner that the first required quantity becomes equal to or less than a quantity according to a predetermined stockout probability, the first required quantity corresponding to a quantity which becomes necessary as the inventory, when the failure-predicted quantity of the part fails to operate properly at the first failure rate with a lead time of the part.
3. The terminal according to claim 1, wherein,
the control section calculates the second required quantity according to a Poisson distribution, in such a manner that the second required quantity becomes equal to or less than a quantity according to a predetermined stockout probability, the second required quantity corresponding to a quantity which becomes necessary as the inventory, when the no-failure-predicted quantity of the part fails to operate properly at the second failure rate with a lead time of the part.
4. The terminal according to claim 1, wherein,
the storage section stores, with respect to each operating equipment, parts inventory information for specifying a predetermined area which includes the operating equipment, the part used in the operating equipment, and an inventory quantity of the part in a warehouse assigned in the area, and
the control section performs,
a process for specifying from the parts inventory information, the inventory quantity of the part which is of the same sort as the failure-predicted part of the operating equipment which obtains from the sensor the value determined as abnormal,
a process for specifying as a replenishing quantity, a value obtained by subtracting the inventory quantity from the required inventory quantity, when the required inventory quantity is larger than the inventory quantity being specified, and
a process for outputting to the output section, an instruction for replenishing the replenishing quantity, from a warehouse other than the warehouse assigned to the predetermined area including the operating equipment which obtains from the sensor the value determined as abnormal.
5. The terminal according to claim 4, wherein,
the control section performs a process for placing an order for a shortage that is obtained by subtracting the inventory quantity of the other warehouse from the replenishing quantity, when the replenishing quantity is larger than the inventory quantity of the warehouse other than the warehouse assigned to the predetermined area including the operating equipment that obtains from the sensor the value determined as abnormal.
6. A program which allows a computer to function as a terminal for managing parts inventory prepared for more than one unit of operating equipment, the program allowing the computer to function as a storage means and a control means;
the storage means storing failure-predicted pattern information including information for specifying;
a failure-predicted pattern which is a pattern of a value obtained from a sensor monitoring a state of the operating equipment and indicates that a failure is predicted as to a part used in the operating equipment, the part having a possibility of failure occurrence when the failure-predicted pattern appears, and a first failure rate indicating a probability that the part fails to operate properly when the failure is predicted, and
the storage means further storing operating equipment information including information for specifying; the operating equipment, the part used in the operating equipment, a quantity of the part used in the operating equipment, and a second failure rate indicating the probability that the part fails to operate properly when no failure is predicted, wherein,
the program allowing the control means to perform;
a process for specifying from the failure-predicted pattern information, a failure-predicted pattern which is associated with a pattern of the value, being determined as abnormal when obtained from the sensor which monitors the state of the operating equipment,
a process for specifying the part having a possibility of malfunction as a failure-predicted part according to the failure-predicted pattern being specified,
a process for specifying as a failure-predicted quantity from the operating equipment information, being a quantity of the failure-predicted part used in the operating equipment that has the value obtained from the sensor being determined as abnormal,
a process for specifying as a no-failure-predicted quantity from the operating equipment information, being the quantity of the part of the same sort as the failure-predicted part, used in operating equipment other than the operating equipment that has the value obtained from the sensor being determined as abnormal, among at least one unit of the operating equipment,
a process for calculating a first required quantity that is required as an inventory, when the part corresponding to the failure-predicted quantity fails to operate properly at the first failure rate,
a process for calculating a second required quantity that is required as the inventory, when the part corresponding to the no-failure-predicted quantity fails to operate properly at the second failure rate, and
a process for calculating a required inventory quantity of the part that is of the same sort as the failure-predicted part, by adding the first required quantity and the second required quantity.
7. The program according to claim 6, allowing the control means to calculate the first required quantity according to a Poisson distribution, in such a manner that the first required quantity becomes equal to or less than a quantity according to a predetermined stockout probability, the first required quantity corresponding to a quantity which becomes necessary as the inventory, when the failure-predicted quantity of the part fails to operate properly at the first failure rate with a lead time of the part.
8. The program according to claim 6, allowing the control means to calculate the second required quantity according to a Poisson distribution, in such a manner that the second required quantity becomes equal to or less than a quantity according to a predetermined stockout probability, the second required quantity corresponding to a quantity which becomes necessary as the inventory, when the no-failure-predicted quantity of the part fails to operate properly at the second failure rate with a lead time of the part.
9. The program according to claim 6,
allowing the storage means to store, with respect to each operating equipment, parts inventory information for specifying a predetermined area which includes the operating equipment, the part used in the operating equipment, and an inventory quantity of the part in a warehouse assigned in the area, and
allowing the control means to perform,
a process for specifying from the parts inventory information, the inventory quantity of the part which is of the same sort as the failure-predicted part of the operating equipment which obtains from the sensor the value determined as abnormal,
a process for specifying as a replenishing quantity, a value obtained by subtracting the inventory quantity from the required inventory quantity, when the required inventory quantity is larger than the inventory quantity being specified, and
a process for outputting to the output section, an instruction for replenishing the replenishing quantity, from a warehouse other than the warehouse assigned to the predetermined area including the operating equipment which obtains from the sensor the value determined as abnormal.
10. The program according to claim 9, allowing the control means to perform a process for placing an order for a shortage that is obtained by subtracting the inventory quantity of the other warehouse from the replenishing quantity, when the replenishing quantity is larger than the inventory quantity of the warehouse other than the warehouse assigned to the predetermined area including the operating equipment that obtains from the sensor the value determined as abnormal.
11. An inventory management method in which a terminal manages parts inventory prepared for more than one unit of operating equipment, the terminal comprising a storage section and a control section;
the storage section storing failure-predicted pattern information including information for specifying; a failure-predicted pattern which is a pattern of a value obtained from a sensor monitoring a state of the operating equipment and indicates that a failure is predicted as to a part used in the operating equipment, the part having a possibility of failure occurrence when the failure-predicted pattern appears, and a first failure rate indicating a probability that the part fails to operate properly when the failure is predicted, and
the storage section further storing operating equipment information including information for specifying; the operating equipment, the part used in the operating equipment, a quantity of the part used in the operating equipment, and a second failure rate indicating the probability that the part fails to operate properly when no failure is predicted, wherein,
the control section comprising the steps of;
specifying from the failure-predicted pattern information, a failure-predicted pattern which is associated with a pattern of the value being determined as abnormal when obtained from the sensor which monitors the state of the operating equipment,
specifying the part having a possibility of malfunction as a failure-predicted part according to the failure-predicted pattern being specified,
specifying as a failure-predicted quantity from the operating equipment information, being a quantity of the failure-predicted part used in the operating equipment that has the value obtained from the sensor being determined as abnormal,
specifying as a no-failure-predicted quantity from the operating equipment information, being the quantity of the part of the same sort as the failure-predicted part, used in operating equipment other than the operating equipment that has the value obtained from the sensor being determined as abnormal, among at least one unit of the operating equipment,
calculating a first required quantity that is required as an inventory, when the part corresponding to the failure-predicted quantity fails to operate properly at the first failure rate,
calculating a second required quantity that is required as the inventory, when the part corresponding to the no-failure-predicted quantity fails to operate properly at the second failure rate, and
calculating a required inventory quantity of the part that is of the same sort as the failure-predicted part, by adding the first required quantity and the second required quantity.