Galvanically isolated functional test for components
AssigneeSiemens Aktiengesellschaft
InventorsSimon Hüttinger, Thomas Komma, Kai Kriegel, Jürgen Rackles, Gernot Spiegelberg
Life of this patent
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Abstract
A method and a circuit functionally test a semiconductor component. The functional test is performed with galvanic isolation by using a transformer. The test itself is based on determining the frequency-dependent impedance of a series circuit of capacitors and inductors using the semiconductor component itself. The impedance is strongly influenced by the conduction state of the semiconductor component, in other words, by the instantaneous conductivity or blocking capability of the semiconductor component.
Claims10
A method for testing a switch, comprising:
- connecting the switch to an electrical test circuit which has a transformer;
- producing an AC voltage in the test circuit;
- determining an impedance of the test circuit and the switch for the AC voltage;
- selecting a conductivity state of the switch to be tested, the conductivity state being selected from first and second conductivity states, the first conductivity state representing the switch being switched-on, and the second conductivity state representing the switch being switched-off;
- and
- selecting a frequency for the AC voltage, which is matched to the conductivity state to be tested, wherein the frequency is selected such that when the switch is in at least one of the first and second conductivity states, the impedance determined should be virtually zero.
A test circuit for functional testing of a switch, comprising:
- a transformer;
- a feed circuit to produce an AC voltage at a testing frequency;
- and
- at least one measurement circuit to determine an impedance of the test circuit and the switch at the testing frequency,
- to select a conductivity state of the switch to be tested, the conductivity state being selected from first and second conductivity states, the first conductivity state representing the switch being switched-on, and the second conductivity state representing the switch being switched-off, and to select a frequency for the AC voltage, which is matched to the conductivity state to be tested, wherein the frequency is selected such that when the switch is in at least one of the first and second conductivity states, the impedance determined should be virtually zero.
An electrical circuit comprising:
- at least one switch;
- and
- a test circuit comprising:
- a transformer;
- a feed circuit to produce an AC voltage at a testing frequency;
- and
- at least one measurement circuit to determine an impedance of the test circuit and the component at the testing frequency,
- to select a conductivity state of the switch to be tested, the conductivity state being selected from first and second conductivity states, the first conductivity state representing the at least one switch being switched-on, and the second conductivity state representing the at least one switch being switched-off, and to select a frequency for the AC voltage, which is matched to the conductivity state to be tested, wherein the frequency is selected such that when the switch is in at least one of the first and second conductivity states, the impedance determined should be virtually zero.
A converter circuit having overvoltage protection, comprising:
- a converter to convert a single-phase voltage to a three-phase voltage;
- a diode, which is provided on a single-phase side of the converter;
- a semiconductor switch that includes a diode, the semiconductor switch being provided on a single-phase side of the converter;
- a single-phase battery, which is connected to the single-phase side of the converter;
- and
- a test circuit comprising:
- a transformer;
- a feed circuit to produce an AC voltage at a testing frequency;
- and
- at least one measurement circuit to determine an impedance of the semiconductor switch at the testing frequency.
Dependencies are inferred from the claim text.