The RC Network Analyzer Using the High Permittivity Ceramics and its Applications

Described in this paper are the design considerations of the simple element of the two-dimensional RC distributed constant circuit and its applications for the analysis of the transient heat conduction problems in engineering work. This element is formed by coating with the resistive film the upper surface of the high permittivity ceramics plate whose back side to be silvered. In addition to a resistivity of every elementary area within the resistive film, there exists capacitive coupling between the area and ground. This element can be regarded as a typical two-dimensional RC distributed system and utilized as a simulator for the same dimensional heat conduction system. It has a convenience and high accuracy for the analysis of the transient heat conduction problems in engineering work

A Method of Direct Analog Simulation Using Transistor Switches and its Applications

In the analog circuits for the systms governed by the dilfercntial equations with the coefficients which are a function of one or mOre of the dependent variables, the magnitudes of their circuit elements must be variable in accordance with the nature of the function. Such circuit elements can be realized by means of inserting or removing the additional elements with high speed switches in the analog circuits. Particularly, in the case of varying stepwise this method is effective. But as an analog circuit is regarded as a short-time or repetitive type analyzer, the above switches must be instantaneous operation. In this paper, first, it is made sure by the experiments that some of the transistor switches arc met this condition, and moreover arc very low closed resistance, very high open resistance and neglegible small voltage offsets. Next, the basic technique for the direct analog simulation usiug transistor switches is described about the simple example, i.e. the oscillatory system with varying cross-scctional surge tank. Finally, as its applications, the transient problems of these oscillatory systems arc solved by means of these analog circuits

A Method of Automatic Washing for Salt Contaminated Insulators

Described in this paper is a method of automatic washing for salt contaminated insulators. An average value of leakage current through the surface of the pilot insulator in a duration is measured, for this is a function of the quantity of salt adhered and its moisture content. In each cycle, the program signals give one by one the instructions on a start and an end of the integration of leakage current, a detection of the integrated value, a stop of the washing device and a reset of the integrator. The integrator consists of RC circuit and the main detecting part consists of the thyristor whose firing gate voltage is used as a reference value. If the integrator output rises above the firing gate voltage, the pulse signals are made in the signal conversion part at the same time that the thyristor turns on, which are distributed to the pump motor or the electromagnetic valve. Then the insulators on hot-line are washed all together in the appointed duration. Finally, by the various experiments this method was proved to have enough accuracy and reliability in practical use. The conclusions are summarized as follows. (1) An average value of leakage current is justified to be the detecting variable. (2) The RC circuit used as the integrator is proved to be easy in maintenance. (3) Because of the fairly short duration of the detecting action, the integrator is kept in a sufficiently safe condition under expected environment