IPC분류정보
국가/구분 |
United States(US) Patent
등록
|
국제특허분류(IPC7판) |
|
출원번호 |
US-0973389
(2010-12-20)
|
등록번호 |
US-8698484
(2014-04-15)
|
우선권정보 |
TW-98144328 A (2009-12-22) |
발명자
/ 주소 |
|
출원인 / 주소 |
|
대리인 / 주소 |
|
인용정보 |
피인용 횟수 :
0 인용 특허 :
2 |
초록
▼
An over-voltage and over-temperature detecting circuit includes a voltage-limiting circuit, a temperature sensing circuit, a current source, a first comparing circuit and a second comparing circuit. The equivalent resistance of the temperature sensing circuit varies with the temperature. The current
An over-voltage and over-temperature detecting circuit includes a voltage-limiting circuit, a temperature sensing circuit, a current source, a first comparing circuit and a second comparing circuit. The equivalent resistance of the temperature sensing circuit varies with the temperature. The current source provides a first current to a detecting terminal, so that a detecting voltage is generated at the detecting terminal. By comparing the magnitude of the detecting voltage with the first reference voltage value, the first comparing circuit generates a corresponding temperature status signal. By comparing the magnitude of the detecting voltage with the second reference voltage value, the second comparing circuit generates a corresponding voltage status signal. If the temperature exceeds the temperature upper limit, the temperature status signal is in an enabling status. If the first voltage exceeds the voltage upper limit, the voltage status signal is in an enabling status.
대표청구항
▼
1. An over-voltage and over-temperature detecting circuit for judging whether a temperature exceeds a temperature upper limit or a first voltage exceeds a voltage upper limit, said over-voltage and over-temperature detecting circuit comprising: a voltage-limiting circuit interconnected between a vol
1. An over-voltage and over-temperature detecting circuit for judging whether a temperature exceeds a temperature upper limit or a first voltage exceeds a voltage upper limit, said over-voltage and over-temperature detecting circuit comprising: a voltage-limiting circuit interconnected between a voltage source of said first voltage and a detecting terminal for limiting and controlling the electrical energy magnitude of said first voltage to be transmitted to said detecting terminal through said voltage-limiting circuit;a temperature sensing circuit interconnected between said detecting terminal and a common terminal, wherein the equivalent resistance of said temperature sensing circuit varies with said temperature;a current source connected to said detecting terminal for providing a first current to said detecting terminal, so that a detecting voltage is generated at said detecting terminal;a first comparing circuit connected to said detecting terminal and receiving a first reference voltage value, wherein by comparing the magnitude of said detecting voltage with said first reference voltage value, said first comparing circuit generates a corresponding temperature status signal; anda second comparing circuit connected to said detecting terminal and receiving a second reference voltage value, wherein by comparing the magnitude of said detecting voltage with said second reference voltage value, said second comparing circuit generates a corresponding voltage status signal,wherein if said temperature exceeds said temperature upper limit, said temperature status signal is in an enabling status, and if said first voltage exceeds said voltage upper limit, said voltage status signal is in an enabling status;wherein said voltage-limiting circuit has a limiting voltage value, and if the magnitude of said first voltage increases and is higher than a limiting voltage value, the electrical energy of said first voltage is transmitted to said detecting terminal through said voltage-limiting circuit, so that the magnitude of a second current flowing into said temperature sensing circuit and the magnitude of said detecting voltage increase. 2. The over-voltage and over-temperature detecting circuit according to claim 1, wherein if the magnitude of said first voltage is lower than said limiting voltage value, the electrical energy of said first voltage fails to be transmitted to said detecting terminal through said voltage-limiting circuit. 3. The over-voltage and over-temperature detecting circuit according to claim 1, wherein said voltage-limiting circuit comprises a Zener diode, which is interconnected to said voltage source of said first voltage and said detecting terminal for limiting and controlling the electrical energy magnitude of said first voltage to be transmitted to said detecting terminal through said voltage-limiting circuit. 4. The over-voltage and over-temperature detecting circuit according to claim 1, wherein as said temperature increases, said equivalent resistance of said temperature sensing circuit decreases, and the magnitude of said detecting voltage decreases. 5. The over-voltage and over-temperature detecting circuit according to claim 4, wherein as said temperature decreases, said equivalent resistance of said temperature sensing circuit increases, and the magnitude of said detecting voltage increases. 6. The over-voltage and over-temperature detecting circuit according to claim 4, wherein said temperature sensing circuit includes a first negative temperature coefficient thermister, which is interconnected between said detecting terminal and said common terminal. 7. The over-voltage and over-temperature detecting circuit according to claim 6, wherein said temperature sensing circuit further includes a second negative temperature coefficient thermister connected with said first negative temperature coefficient thermister in series. 8. The over-voltage and over-temperature detecting circuit according to claim 1, wherein said first comparing circuit comprises a first operational amplifier, said first operational amplifier has a positive input terminal receiving said first reference voltage value and a negative input terminal connected to said detecting terminal, and said first operational amplifier compares the magnitude of said detecting voltage with said first reference voltage value, thereby generating said temperature status signal. 9. The over-voltage and over-temperature detecting circuit according to claim 8, wherein as said temperature increases and exceeds said temperature upper limit, the magnitude of said detecting voltage is lower than said first reference voltage value, so that said temperature status signal outputted from said first operational amplifier is in said enabling status. 10. The over-voltage and over-temperature detecting circuit according to claim 8, wherein as said temperature decreases and is below said temperature upper limit, the magnitude of said detecting voltage is higher than said first reference voltage value, so that said temperature status signal outputted from said first operational amplifier is switched to a disabling status. 11. The over-voltage and over-temperature detecting circuit according to claim 8, wherein said first comparing circuit further comprises a first debouncing circuit for reducing influence of noise on said temperature status signal. 12. The over-voltage and over-temperature detecting circuit according to claim 1, wherein said second comparing circuit comprises a second operational amplifier, said second operational amplifier has a negative input terminal receiving said second reference voltage value and a positive input terminal connected to said detecting terminal, and said second operational amplifier compares the magnitude of said detecting voltage with said second reference voltage value, thereby generating said voltage status signal. 13. The over-voltage and over-temperature detecting circuit according to claim 12, wherein as said first voltage increases and exceeds said voltage upper limit, the magnitude of said detecting voltage is higher than said second reference voltage value, so that said voltage status signal outputted from said second operational amplifier is in said enabling status. 14. The over-voltage and over-temperature detecting circuit according to claim 12, wherein as said first voltage decreases and is below said voltage upper limit, the magnitude of said detecting voltage is lower than said second reference voltage value, so that said voltage status signal outputted from said second operational amplifier is switched to a disabling status. 15. The over-voltage and over-temperature detecting circuit according to claim 12, wherein said second comparing circuit further comprises a second debouncing circuit for reducing influence of noise on said voltage status signal. 16. The over-voltage and over-temperature detecting circuit according to claim 1, wherein said current source is a constant current source for receiving the electrical energy of a second voltage and generating said first current with a constant current value to said detecting terminal, and the magnitude of said second voltage is lower than said second reference voltage value. 17. The over-voltage and over-temperature detecting circuit according to claim 1, further comprising a first switch element, which is interconnected between said detecting terminal and said current source, wherein a second voltage set value is received by a control terminal of said first switch element, and said second voltage set value is lower than a difference between said second reference voltage value and a threshold voltage value of said first switch element. 18. The over-voltage and over-temperature detecting circuit according to claim 1, wherein said current source is a variable current source, and the magnitude of said first current varies with said second reference voltage value, wherein if the magnitude of said first voltage is lower than said voltage upper limit, said detecting voltage is limited to be lower than said second reference voltage value. 19. The over-voltage and over-temperature detecting circuit according to claim 1, wherein said current source is a variable current source, and the magnitude of said first current varies with said temperature, and wherein if the magnitude of said first voltage is lower than said voltage upper limit, said detecting voltage is limited to be lower than said second reference voltage value.
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