Semiconductor switch including a device for measuring a depletion layer temperature of the switch
First Claim
1. A semiconductor switch including a device for measuring a depletion-layer temperature of a semiconductor switch (V) which conducts load current through load current conductors including at least first and second load current conductors, the device comprising:
- a network (N) having an output and at least one RC member which electrically simulates thermal characteristics of the semiconductor switch (V), a converter (W) provided between the first load current conductor of the semiconductor switch (V) and the network (N) for producing a current (iV) which is proportional to a power dissipation in the semiconductor switch (V) and a comparator (A) having a first input which is connected to the output of the network (N), a second input to which a signal which is proportional to a permissible depletion-layer temperature is supplied and having an output, the semiconductor switch (V) having an electrode (G) which controls the load current in the semiconductor switch (V), the converter element (W) being constructed as an ohmic resistor (RW), a first series circuit including the converter element (W), a first switch element (S1), and a capacitor (C1) of the network (N) connected parallel to the first and second load current conductors;
a second series circuit including an ohmic resistor (R1) of the network (N), a second switch element (S2) and a first voltage source (Uoff) connected parallel to the capacitor (C1);
the electrode (G) which controls the load current being connected via a third switch element (S0) to a second voltage source (Uon);
the comparator output being coupled to act on said first switch element (S1), said second switch element (S2), and said third switch element (S0).
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Accused Products
Abstract
A semiconductor switch includes a device for measuring the depletion-layer temperature of a semiconductor rectifier (V) which conducts load current. This device consists of a network (N) which electrically simulates the thermal behavior of the semiconductor rectifier (V), a converter element (W) provided between semiconductor rectifier (V) and the network (N) for producing a current (iv) which is proportional to the power dissipation in the semiconductor rectifier (V), and a comparator (A) which is controlled by the output of the network (N) and acts on the semiconductor rectifier (V). The semiconductor rectifier has a simple construction, is secured against short circuits and overloads and at the same time is also capable of easily controlling capacitive loads. This is achieved so that, on the one hand, the converter element (W) is configured as an ohmic resistor (Rw) and is connected together with a first switch element (S1) and a capacitor (C1) of the network (N) in parallel to the semiconductor rectifier (V). On the other hand, two voltage source (Uoff, Uon) are provided which are controlled via further switches (S0 and S2) by the comparator (A) which acts on the semiconductor rectifier (V).
8 Citations
3 Claims
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1. A semiconductor switch including a device for measuring a depletion-layer temperature of a semiconductor switch (V) which conducts load current through load current conductors including at least first and second load current conductors, the device comprising:
a network (N) having an output and at least one RC member which electrically simulates thermal characteristics of the semiconductor switch (V), a converter (W) provided between the first load current conductor of the semiconductor switch (V) and the network (N) for producing a current (iV) which is proportional to a power dissipation in the semiconductor switch (V) and a comparator (A) having a first input which is connected to the output of the network (N), a second input to which a signal which is proportional to a permissible depletion-layer temperature is supplied and having an output, the semiconductor switch (V) having an electrode (G) which controls the load current in the semiconductor switch (V), the converter element (W) being constructed as an ohmic resistor (RW), a first series circuit including the converter element (W), a first switch element (S1), and a capacitor (C1) of the network (N) connected parallel to the first and second load current conductors;
a second series circuit including an ohmic resistor (R1) of the network (N), a second switch element (S2) and a first voltage source (Uoff) connected parallel to the capacitor (C1);
the electrode (G) which controls the load current being connected via a third switch element (S0) to a second voltage source (Uon);
the comparator output being coupled to act on said first switch element (S1), said second switch element (S2), and said third switch element (S0).- View Dependent Claims (2, 3)
Specification
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- Resources
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Current AssigneeASEA Brown Boveri SA de CV (ABB Limited)
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Original AssigneeASEA Brown Boveri SA de CV (ABB Limited)
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InventorsHobelsberger, Max
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Primary Examiner(s)Callahan, Timothy P.
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Application NumberUS07/588,018Time in Patent Office777 DaysField of Search361/103, 307/572, 307/573, 307/304, 307/443, 307/310, 307/570US Class Current327/512CPC Class CodesH02H 6/00 Emergency protective circui...H03K 17/0822 in field-effect transistor ...
