Abstract: Provided is a material testing system that can prevent the influence of noise to obtain an adequate test result by reducing a variation in test force in a plastic region. The material testing system is provided with: a displacement meter 15 that measures a displacement in distance between gage marks on a test piece 10; measuring means adapted to measure a displacement in rotational angle of a servo motor 31 that moves a crosshead 13; a computing part 48 that successively computes a change ratio R that is a ratio between the displacement in distance and the displacement in rotational angle; and a feedback control part 49 that, on the basis of the change ration R, performs feedback control of the servo motor 31, wherein when the change ratio R exceeds a setting value, a value of a parameter K used for the feedback control is changed to a value that makes the influence of the feedback control small.

Abstract: Provided is a material testing system that can prevent the influence of noise to obtain an adequate test result by reducing a variation in test force in a plastic region. The material testing system is provided with: a displacement meter 15 that measures a displacement in distance between gage marks on a test piece 10; measuring means adapted to measure a displacement in rotational angle of a servo motor 31 that moves a crosshead 13; a computing part 48 that successively computes a change ratio R that is a ratio between the displacement in distance and the displacement in rotational angle; and a feedback control part 49 that, on the basis of the change ration R, performs feedback control of the servo motor 31, wherein when the change ratio R exceeds a setting value, a value of a parameter K used for the feedback control is changed to a value that makes the influence of the feedback control small.

Abstract: A plug-in unit includes a breaker electrically connected with a busbar at a power supply side and an electric device electrically connected with the breaker. Joint surfaces making contact with each other are formed at the breaker and the electric device, respectively. The breaker includes a terminal metal fitting connecting the busbar thereto and a plug-in terminal metal fitting installed at the joint surface of the breaker, and the electric device includes a plug terminal, which is installed at the joint surface thereof and capable of being connected with the plug-in terminal metal fitting. The breaker is detachably joined with the electric device by an engaging member including an engaging unit and an engagement receiving unit. The engaging unit and the engagement receiving unit are installed at the joint surfaces of the breaker and the electric device, respectively, and detachably engaged with each other.

Abstract: A material testing machine is provided, in which a motor is used as a driving source of a loading mechanism, and the material testing machine can always perform a material test accurately, without requiring skilled operators, trial and error, or a longer time when setting control gains. A ratio K(t) of an inspection value F(t) of a control quantity to a displacement ?(t) of a motor 21 is calculated sequentially, and a value proportional to a value obtained by dividing a deviation {FD(t)?F(t)} by the calculated ratio K(t) is taken as a rotation angle command and supplied to a servo amplifier 36. The servo amplifier 36 supplies a current to the motor 21. Therefore, as the test proceeds, appropriate gains are automatically calculated and set, a gain setting operation before test is not necessary, and the material test can be always performed accurately.

Abstract: A plug-in unit includes a breaker electrically connected with a busbar at a power supply side and an electric device electrically connected with the breaker. Joint surfaces making contact with each other are formed at the breaker and the electric device, respectively. The breaker includes a terminal metal fitting connecting the busbar thereto and a plug-in terminal metal fitting installed at the joint surface of the breaker, and the electric device includes a plug terminal, which is installed at the joint surface thereof and capable of being connected with the plug-in terminal metal fitting. The breaker is detachably joined with the electric device by an engaging member including an engaging unit and an engagement receiving unit. The engaging unit and the engagement receiving unit are installed at the joint surfaces of the breaker and the electric device, respectively, and detachably engaged with each other.

Abstract: A material testing machine is provided, in which a motor is used as a driving source of a loading mechanism, and the material testing machine can always perform a material test accurately, without requiring skilled operators, trial and error, or a longer time when setting control gains. A ratio K(t) of an inspection value F(t) of a control quantity to a displacement ?(t) of a motor 21 is calculated sequentially, and a value proportional to a value obtained by dividing a deviation {FD(t)?F(t)} by the calculated ratio K(t) is taken as a rotation angle command and supplied to a servo amplifier 36. The servo amplifier 36 supplies a current to the motor 21. Therefore, as the test proceeds, appropriate gains are automatically calculated and set, a gain setting operation before test is not necessary, and the material test can be always performed accurately.

Abstract: A material testing machine includes a load mechanism for applying a load to a test piece, and a plurality of detectors for detecting physical values associated with the applied load. An A/D converter receives the output measurement data of each of the detected physical values, and digitalizes the received output data. The A/D converter has multiple channels, and can select use/nonuse of each of the multiple channels based on an external selection signal. Since the detecting rate and/or the detecting accuracy are inversely proportional to the number of multiple channels in use at one time, the machine enables a user to prioritize between the number of channels in use, the detecting rate, and the detecting accuracy.

Abstract: A material testing machine includes a load mechanism for applying a load to a test piece, and a plurality of detectors for detecting physical values associated with the applied load. An A/D converter receives the output measurement data of each of the detected physical values, and digitalizes the received output data. The A/D converter has multiple channels, and can select use/nonuse of each of the multiple channels based on an external selection signal. Since the detecting rate and/or the detecting accuracy are inversely proportional to the number of multiple channels in use at one time, the machine enables a user to prioritize between the number of channels in use, the detecting rate, and the detecting accuracy.

Abstract: According to this invention, a converter includes a voltage transformer, a switching transistor, a resistor, a control transistor, and a control circuit. The voltage transformer has a primary winding, a secondary winding, and a control winding. The switching transistor is connected in series with the primary winding. The resistor is connected between the switching transistor and one terminal of an input power source. The control transistor has a base connected to a connection point between the resistor and the switching transistor and a collector connected to a control electrode of the switching transistor. The control circuit controls the control transistor on the basis of a control voltage extracted from the control winding.