Title:
INSULATION RESISTANCE DETECTION CIRCUIT
Document Type and Number:
WIPO Patent Application WO/2012/120683
Kind Code:
A1
Abstract:
A CPU (4) calculates an insulation resistance value of a direct current power supply (2) using: a first current value, which is measured on the basis of a voltage (Vm21) (first measured voltage) measured by means of a divided voltage measuring circuit (6), and on a current (Isence1) (first grounding current) measured by means of a current measuring circuit (8), said voltage and said current having been measured when a switch (S1) is opened; and a second current value, which is measured on the basis of a voltage (Vm22) (second measured voltage) measured by means of the divided voltage measuring circuit (6), and a current (Isence2) (second grounding current) measured by means of the current measuring circuit (8), said voltage and said current having been measured when the switch (S1) is closed. Time intervals, at which the switch (S1) is opened and closed, said time intervals determining measuring times for measuring the first and the second current values, are variably set, corresponding to a change quantity between the first and the second grounding currents measured by means of the current measuring circuit (8).
Inventors:
IMAI YOSHITO (JP)
Application Number:
PCT/JP2011/055673
Publication Date:
September 13, 2012
Filing Date:
March 10, 2011
Export Citation:
Assignee:
MITSUBISHI ELECTRIC CORP (JP)
IMAI YOSHITO (JP)
IMAI YOSHITO (JP)
International Classes:
G01R27/18; G01R31/02
Foreign References:
| JPH03179272A | 1991-08-05 | |||
| JP2006526378A | 2006-11-16 | |||
| JPH02237421A | 1990-09-20 | |||
| JPH02221873A | 1990-09-04 |
Attorney, Agent or Firm:
SAKAI, HIROAKI (JP)
Hiroaki Sakai (JP)
Hiroaki Sakai (JP)
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Claims: