Abstract: There is provided an angle type check valve which enables simple and quick replacement operations of a valve body and a valve seat without releasing a piping coupled state and has excellent maintainability. In the angle type check valve according to the present invention, as a valve unit, a valve seat, a valve body, and a hinge mechanism are integrally assembled so as to be made into a unit part. The valve unit is attachable to and detachable from a unit fitting portion in the valve box main body. A gripping member is provided on the valve seat. As a result, access to the valve unit attached to the unit fitting portion through the access hole becomes remarkably easier. Therefore, a maintenance operator can perform a fitting operation and a removal operation of the valve unit to and from the unit fitting portion quickly with high work efficiency.

Abstract: There is provided an angle type check valve which enables simple and quick replacement operations of a valve body and a valve seat without releasing a piping coupled state and has excellent maintainability. The angle type check valve according to the present invention includes: a valve box main body which is provided with an inflow port opened on a lower side, an outflow port opened on a lateral side, and an access hole opened on an upper side, and in which a valve chamber that has a bent shape is formed; a lid body which seals the access hole; a valve seat which is provided with a valve port; a valve body which opens and closes the valve port; and a hinge mechanism which supports the valve body. As a valve unit, the valve seat, the valve body, and the hinge mechanism are integrally assembled so as to be made into a unit part. The valve unit is attached to and detached from a unit fitting portion in the valve box main body.

Abstract: There is provided an angle type check valve which enables simple and quick replacement operations of a valve body and a valve seat without releasing a piping coupled state and has excellent maintainability. The angle type check valve according to the present invention includes: a valve box main body which is provided with an inflow port opened on a lower side, an outflow port opened on a lateral side, and an access hole opened on an upper side, and in which a valve chamber that has a bent shape is formed; a lid body which seals the access hole; a valve seat which is provided with a valve port; a valve body which opens and closes the valve port; and a hinge mechanism which supports the valve body. As a valve unit, the valve seat, the valve body, and the hinge mechanism are integrally assembled so as to be made into a unit part. The valve unit is attached to and detached from a unit fitting portion in the valve box main body.

Abstract: There is provided an angle type check valve which enables simple and quick replacement operations of a valve body and a valve seat without releasing a piping coupled state and has excellent maintainability. In the angle type check valve according to the present invention, as a valve unit, a valve seat, a valve body, and a hinge mechanism are integrally assembled so as to be made into a unit part. The valve unit is attachable to and detachable from a unit fitting portion in the valve box main body. A gripping member is provided on the valve seat. As a result, access to the valve unit attached to the unit fitting portion through the access hole becomes remarkably easier. Therefore, a maintenance operator can perform a fitting operation and a removal operation of the valve unit to and from the unit fitting portion quickly with high work efficiency.

Abstract: An input circuit of a one-chip microcomputer is connected to an external switching circuit. When an analog input signal of a significant level generated in the external switching circuit is received at an analog input terminal of the input circuit, an A/D conversion start request signal is generated in an A/D conversion start request generating circuit and is sent to an A/D converter. The operation of the A/D converter is started in response to the A/D conversion start request signal, the analog input signal received at the analog input terminal is converted into digital data, and an A/D conversion finish signal is sent from the A/D converter to a CPU of the one-chip microcomputer. The operation of the CPU is started in response to the A/D conversion finish signal, and the digital data is readout to the CPU.

Abstract: An input circuit of a one-chip microcomputer is connected to an external switching circuit. When an analog input signal of a significant level generated in the external switching circuit is received at an analog input terminal of the input circuit, an A/D conversion start request signal is generated in an A/D conversion start request generating circuit and is sent to an A/D converter. The operation of the A/D converter is started in response to the A/D conversion start request signal, the analog input signal received at the analog input terminal is converted into digital data, and an A/D conversion finish signal is sent from the A/D converter to a CPU of the one-chip microcomputer. The operation of the CPU is started in response to the A/D conversion finish signal, and the digital data is readout to the CPU.

Abstract: An operation mode transfer system capable of solving a problem of a conventional system in that a processing load of a host computer cannot be reduced as long as a device is physically connected with the host computer because the host computer must carry out, even when the device is inoperative, the same communication processing as that performed when the device is operative. The present system connects a pullup resistor to a pullup power supply to set the device operative, and disconnects it from the pullup power supply to set the device inoperative, in response to the instructions from a CPU of the device.

Abstract: A semiconductor integrated circuit comprising a terminal connected to the ground potential between an input and an output terminal of an oscillator so that a ground wire pattern of sufficient width is provided between the input and output terminals on the wiring substrate.

Abstract: A D/A converter arranged to improve the resolution by changing the number of resistors to be interposed between a resistance ladder, from which a divided voltage between positive and negative voltage sources is taken out, and the positive and negative voltage sources while maintaining the total resistance value at a constant value, in which the resistance value of the resistor to be interposed between the resistance ladder and the positive and negative voltage sources is selected to uniformly lower the divided voltage which is taken by the resistance ladder by a level corresponding to 1/2 LSB to perform 1/2 LSB correction.

Abstract: An analog-to-digital converter includes a comparator for comparing a voltage output by a digital-to-analog converter with an input analog voltage at each bit of an n-bit word. The input analog voltage and the analog output voltage of the digital-to-analog converter are alternatingly used as the reference in the comparison, i.e., for every other bit of the n bits. A one-bit result-of-comparison signal indicative of the result of the comparison is output for each of the n bits. Only alternating result-of-comparison signals are inverted and the inverted and non-inverted result-of-comparison signals are stored in a successive approximation register as the converted digital signal and are supplied to the digital-to-analog converter for use in the comparison.

Abstract: A resistance ladder which divides a potential difference between two power sources into 2.sup.m levels by a resistance group in the center portion, then adjusting the number of resistors which are disposed at the both end portions of the resistance ladder and interposed between the resistors of the center portion and the two power sources so that the division voltages of 2.sup.m levels are changed in (n-m) levels, with the result that the potential difference is divided into 2.sup.n levels. A D-A converter uses the resistance ladder. An A-D converter with the D-A converter which generates a reference voltage to be compared with an input voltage.

Abstract: A signal input/output circuit for a semiconductor integrated circuit being provided with a reset signal input/output terminal 1 which inputs external reset requesting signal REQ from the outside of the semiconductor integrated circuit 10 and outputs internal reset requesting signal TWD generated at the inside, and a reset signal input circuit 3 which is connected to the reset signal input/output terminal 1 through the protection resistance 4 and generates reset signal RST resetting the semiconductor integrated circuit 10 when the external reset requesting signal REQ is inputted to the reset signal input/output terminal 1.