| 摘要 |
A circuit tester, e.g. a microohm meter, comprises a power supply 1, 2, a voltage generator 4, an energy storage device e.g. a capacitor 9, a monitor unit 21 and terminals 11, 12 for connecting to a circuit under test 13. In use, the capacitor is charged to a known voltage and then discharged into the circuit under test. The response from the circuit under test is measured and used to calculate impedance. Safety of the user may be achieved by means of an alarm, shorting the output terminals of the tester when not in use, measuring the load connected before testing to check for the impedance of a human body, or stepping up the voltage in stages to avoid electric shock. Measurements relating to resonant frequency, faults, break down of insulation may also be made. The circuit under test may be an induction motor or a printed circuit board. The device may also be used to measure conductivity of a material. |
