Electricity: electrical systems and devices – Safety and protection of systems and devices – With specific current responsive fault sensor
Reexamination Certificate
2001-11-15
2003-11-18
Toatley, Jr., Gregory J. (Department: 2836)
Electricity: electrical systems and devices
Safety and protection of systems and devices
With specific current responsive fault sensor
C361S100000
Reexamination Certificate
active
06650522
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a semiconductor relay system such as a solid state relay (to be referred to simply as SSR hereinafter), more particularly to a semiconductor relay system having a function to detect a disorder.
PRIOR ART
A semiconductor relay system such as an SSR is for driving a direct load such as a heater, motor, solenoid, etc. For example, an SSR, being driven and controlled by a temperature regulator, controls current passing through a heater or its direct load.
The SSR drives/controls a direct load such as a heater, by switching on/off a semiconductor element such as a triac, based on an element driving signal in response to a control input signal, for example, delivered by a temperature regulator. For example, if the semiconductor element is turned on, voltage across the semiconductor element falls and heat is generated. Therefore, to dissipate the heat, it will be necessary to introduce a heat sink.
Such a conventional semiconductor relay system as described above is often installed in a control panel. However, because the chamber of control panel is made so air-tight that the convection of air thereof is not sufficient, and ambient temperature tends to be high, the semiconductor relay system may be heated to an unduly high temperature, which may cause the semiconductor element such as a triac to be shunted for failure.
In spite of this, according to the conventional semiconductor relay system, it is impossible to reliably detect the failure of the semiconductor element thereof.
This invention has been proposed with the aforementioned situation as a background, and its object is to provide a semiconductor relay system capable of reliably detecting a disorder of a semiconductor element portion thereof.
DISCLOSURE OF THE INVENTION
To attain the above object, the semiconductor relay system of this invention comprising a semiconductor element portion which is inserted between terminals to connect/intercept passage between the terminals in response to an element driving signal, characterized by further comprising a sensor portion which monitors the operation of the semiconductor element portion and delivers a sensor output signal based on the monitoring result; and an element disorder detecting circuit which checks for the presence/absence of a disorder in the semiconductor element portion, based on the element driving signal and the sensor output signal.
As seen from above, according to this invention it is possible to reliably detect a disorder in the semiconductor element portion, because, according to the semiconductor relay system of this invention, detection of a disorder in the semiconductor element portion is achieved based on a sensor output signal incoming from the sensor portion which monitors the operation of the semiconductor element portion, and an element driving signal responsible for driving of the semiconductor element portion.
According to the semiconductor relay system of this invention, the sensor portion comprises an across-element voltage detecting circuit which detects voltage across the semiconductor element portion, and delivers an across-element voltage detection signal, i.e., a sensor output signal based on the detection result; and the element disorder detecting circuit checks for the presence/absence of a disorder in the semiconductor element portion based on the across-element voltage detection signal and the element driving signal.
As seen from above, according to this invention it is possible to reliably detect a disorder in the semiconductor element portion, because, according to the semiconductor relay system of this invention, detection of a disorder in the semiconductor element portion is achieved based on an across-element voltage detection signal indicating the voltage across the semiconductor element portion, and an element driving signal. Moreover, according to this invention it is possible to greatly reduce the size of the system as compared with a semiconductor relay system incorporating a CT (current transformation) type current sensor.
According to the semiconductor relay system of this invention, the across-element voltage detecting circuit delivers an across-element voltage detection signal depending on the presence/absence of an across-element voltage; and the element disorder detecting circuit comprises a logic-based judgement circuit which delivers a logic-based judgement signal depending on the presence/absence of an across-element voltage detection signal and of an element driving signal, and a filtration circuit which delivers an element safety check signal reflecting the presence/absence of a disorder in the semiconductor element portion based on the logic-based judgement signal.
As seen from above, according to this invention it is possible to deliver an accurate element safety check signal being removed of noises accompanying a logic-based judgement signal, because, according to the semiconductor relay system of this invention, delivery of a logic-based judgement signal is achieved depending on the presence/absence of an across-element voltage and of an element driving signal, and delivery of an element safety check signal reflecting the presence/absence of a disorder in the semiconductor element portion is achieved based on the logic-based judgement signal.
The semiconductor relay system of this invention comprises a power circuit for supplying power at least to either the across-element voltage detecting circuit or the element disorder detecting circuit, and the power circuit are supplied power by a load power circuit connected to the terminals.
As seen from above, according to this invention it is possible to securely prevent the across-element voltage detecting circuit and the element disorder detecting circuit from making an erroneous detection of a disorder in the semiconductor element portion, even if power supply from the load power circuit is discontinued, because then power supply to the across-element voltage detection circuit and to the element disorder detecting circuit is also discontinued.
The semiconductor relay system of this invention comprises a load circuit for driving a load being energized by a load power supply, and a semiconductor element portion for controlling the load circuit, and further comprises a dummy load portion connected in parallel with the load, and a control circuit for controlling the dummy load portion and the semiconductor element portion.
Further, the semiconductor relay system of this invention comprises a load circuit for driving a load being energized by a load power supply, and a semiconductor element portion for controlling the load circuit, and further comprises a dummy load portion connected in parallel with the load; a for-safety intercepting portion for connecting/intercepting the load with or from the lord power supply in the load circuit; and a control circuit for controlling the dummy load portion, semiconductor element portion and for-safety intercepting portion.
The semiconductor relay system of this invention comprises a load circuit for driving a load being energized by a load power supply; a for-safety intercepting portion having contacts through which connection/interception of the load with/from the load power supply is achieved in the load circuit; a dummy load portion which enables disorder detection by insuring a route for the passage through the semiconductor element portion in case passage through the load is intercepted; and a control means, wherein the control means puts the system into an initial check state when power is turned on during a state where no power is supplied to the semiconductor element portion, dummy load portion and for-safety intercepting portion, and then checks for the presence of disorder in the for-safety intercepting portion; when it finds, based on the detection result, the for-safety intercepting portion is not in disorder, the control means checks for the presence of disorder in the semiconductor element portion; and when it finds, based on the detection result, the semiconductor eleme
Harada Kazuhiro
Hashimoto Yuji
Horibata Kenji
Nakamura Toshiyuki
Nakayama Teruyuki
Benenson Boris
Foley & Lardner
Omron Corporation
Toatley , Jr. Gregory J.
LandOfFree
Semiconductor relay system and method for controlling the... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Semiconductor relay system and method for controlling the..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Semiconductor relay system and method for controlling the... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3117851