Abstract: A measuring device includes a first space for pressurizing a pressurization target and a second space independent of the first space. The measuring device includes a first exhaust valve closing or opening a communication port communicating the first space with another space. An open/closed state of the first exhaust valve changes in accordance with a pressure difference between the first space and the second space.

Abstract: Buck-boost type or buck type chopper circuits and transistors are employed as inverters (IV1, IV2) and power synchronizing switches (SW1, SW2), respectively. A PWM signal is applied to transistors of the chopper circuits to convert DC voltage generated by solar cells (DC1, DC2) into positive and negative half-wave AC voltages for an AC power supply (AC1). The inverters (IV1, IV2) output the AC voltages from their AC output terminals on alternate half cycles thereby to cause backflow of power. The power synchronizing switches (SW1, SW2) performs not only the function of transmitting the half-wave AC voltages generated by the inverters (IV1, IV2) to the AC power supply (AC1) in accordance with the AC cycle of the AC power supply (AC1), but also the function of, when one of the inverters is in operation, insulating the other from the AC power supply (AC1).

Abstract: A pulse generating circuit comprises means for charging from a DC power source through a resistor for charge to a capacitor; means for detecting a predetermined value of charge of the capacitor and triggering a main thyristor to discharge the charge of the capacitor through the main thyristor and means for generating the pulse output to a load by the discharge current.

Abstract: A pulse generating circuit is provided by charging from a DC power source through charging resistor to a capacitor; detecting the preset value of the charging condition of the capacitor; discharging the charge of the capacitor through a main thyristor by triggering the main thyristor and generating a pulse output to a load by the discharging current. The pulse generating circuit comprises a shunt circuit for dividing the voltage of the DC power source beside the circuit for charging the capacitor whereby the potential of the shunt point is compared with the charged voltage of the capacitor through a three terminal trigger element and the trigger element is turned on when the charged voltage of the capacitor becomes substantially equal to the voltage of the DC power source to obtain the trigger output of the main thyristor.

Abstract: A thyristor circuit for generating a pulse current is provided having a by-pass circuit of a predetermined impedance which is placed in parallel to a saturable reactor. In this manner a small current is passed through the by-pass circuit during the unsaturated period of the saturable reactor so as to saturate the saturable reactor after enlarging the turn-on region of the thyristor to pass a pulse current having a high di/dt.