摘要:
Capacitors act as bootstrap capacitors of a high side control circuits. The capacitors are charged in a period in which all of high arm switching devices are non-conductive, so-called in a precharge period. When any of U-phase current, V-phase current and W-phase current is smaller than a negative predetermined value (when an absolute value is larger), it is judged which is the largest value. The low arm switching device is turned on only for a phase corresponding to the current of the largest value and the low arm switching devices of other phases are turned off.
摘要:
A current detector and a voltage detector respectively detect a current value and a voltage value outputted from an engine generator. An operating block determines a weight constant on the basis of the current value and the voltage value, weights the operating time of an engine by using the weight constant, and integrates the weighted operating time to calculate an integral time. A judging block compares the integral time and a reference time, and gives a notification to an indicator when it judges that the integral time exceeds the reference time. Receiving the notification, the indicator makes an external indication. The current detector and the voltage detector can be made of electric circuitry, so that the life of the engine can be predicted at low costs and with high reliability.
摘要:
In a positioning apparatus (40), a fixed scroll (34) is positioned with respect to an assembly body (11) in which a compressor motor (25) has been incorporated. In positioning the fixed scroll (34), electric power is supplied to the compressor motor (25) from an inverter (81) to rotate a crank shaft (20) by the compressor motor (25), thereby shifting a movable scroll (31). In the positioning apparatus (40), the shift of the movable scroll (31) leads to calculation of an appropriate position of the fixed scroll (34). A striking unit (70) applies impact force to the fixed scroll (34) to stir the fixed scroll (34) to the appropriate position.
摘要:
An apparatus for warm up control of an autonomous inverter-driven hydraulic unit has a warm up control section and a switch section. The warm up control section performs a predetermined process using a current speed and current pressure as input information and outputs a first switch command. The switch section is controlled by the first switch command so as to control on/off of power supplied to a fan motor. The apparatus causes an oil temperature to quickly rise to a level where a hydraulic unit driven by a hydraulic pump can work in an optimum condition.