Abstract: An exemplary testing system and method are disclosed for mechanical testing and evaluation of geogrids and other geosynthetic materials to improve load distribution, durability, and performance. The exemplary testing apparatus and method are capable of uniaxial, biaxial, and triaxial testing on different geogrids and other geosynthetic building material, including all types of commercially available geogrids (uniaxial, biaxial, triaxial), geotextiles (woven, non-woven), as well as new-generation geogrids (including spider-web inspired that have hexagonal and other multi-scaled structures). The test apparatus can perform static (monotonic) application of load as well as cyclic tests on geosynthetic materials.

Abstract: A voltage conversion device includes a first conversion circuit configured to switch a DC voltage at a DC power supply to convert the DC voltage into an AC voltage, a second conversion circuit configured to rectify the AC voltage converted with the first conversion circuit to convert the AC voltage into a DC voltage, a controller configured to control switching operation of the first conversion circuit, and emergency power supply circuits (a clamp circuit and a constant-voltage circuit) provided between a connection point of an auxiliary switching element and a capacitor and the controller. When an input voltage at the DC power supply decreases due to start-up of a starter motor in releasing idling stop of a vehicle, the emergency power supply circuits obtain a power supply voltage necessary for operation of the controller from a voltage at the connection point, and supply the power supply voltage to the controller.

Abstract: A voltage conversion device includes a first conversion circuit, a second conversion circuit, a voltage detection circuit, and a CPU (failure detector). The first conversion circuit switches a DC voltage at a DC power supply to convert the DC voltage into an AC voltage. The second conversion circuit rectifies the AC voltage converted with the first conversion circuit to convert the AC voltage into a DC voltage. The voltage detection circuit detects voltage at a connection point of an auxiliary switching element and a first capacitor. The CPU monitors a change in voltage at the connection point in a predetermined period, the voltage being detected with the voltage detection circuit, and detects failure that occurs in one of or both a main switching element and the auxiliary switching element during operation based on the change in the voltage.

Abstract: A voltage conversion device includes a first conversion circuit configured to switch a DC voltage at a DC power supply to convert the DC voltage into an AC voltage, a second conversion circuit configured to rectify the AC voltage converted with the first conversion circuit to convert the AC voltage into a DC voltage, a controller configured to control switching operation of the first conversion circuit, and emergency power supply circuits (a clamp circuit and a constant-voltage circuit) provided between a connection point of an auxiliary switching element and a capacitor and the controller. When an input voltage at the DC power supply decreases due to start-up of a starter motor in releasing idling stop of a vehicle, the emergency power supply circuits obtain a power supply voltage necessary for operation of the controller from a voltage at the connection point, and supply the power supply voltage to the controller.

Abstract: A voltage conversion device includes a first conversion circuit, a second conversion circuit, a voltage detection circuit, and a CPU (failure detector). The first conversion circuit switches a DC voltage at a DC power supply to convert the DC voltage into an AC voltage. The second conversion circuit rectifies the AC voltage converted with the first conversion circuit to convert the AC voltage into a DC voltage. The voltage detection circuit detects voltage at a connection point of an auxiliary switching element and a first capacitor. The CPU monitors a change in voltage at the connection point in a predetermined period, the voltage being detected with the voltage detection circuit, and detects failure that occurs in one of or both a main switching element and the auxiliary switching element during operation based on the change in the voltage.