Low Voltage Insulation Resistance Measurement of Printed Circuits and its Implications

Circuit World ◽  
1988 ◽  
Vol 14 (2) ◽  
pp. 21-25 ◽  
Author(s):  
B.N. Ellis
Keyword(s):  
Low Voltage ◽  
Resistance Measurement ◽  
Insulation Resistance ◽  
Printed Circuits

The Effectiveness of Screening Techniques for Revealing Cracks in High Volumetric Efficiency MLCCs

2013 ◽  
Vol 2013 (1) ◽  
pp. 000651-000656
Author(s):  
Alexander Teverovsky
Keyword(s):  
Low Voltage ◽  
Dissipation Factor ◽  
Volumetric Efficiency ◽  
Insulation Resistance ◽  
Leakage Currents ◽  
Multilayer Ceramic Capacitors ◽  
Screening Techniques ◽  
Ceramic Capacitors ◽  
Defects Analysis ◽  
Electronic Assemblies

Multilayer ceramic capacitors (MLCCs) constitute the majority of components used in electronic assemblies and most of their failures are related to cracks. It is often assumed that dissipation factor (DF), insulation resistance (IR), and breakdown voltage (VBR) are characteristics that are sensitive to the presence of mechanical defects, and screening of capacitors by measurements of these characteristics, and by dielectric withstanding voltage (DWV) testing assures high quality products. This work analyzes the effectiveness of these screening techniques for revealing cracks in high-volumetric efficiency, low-voltage ceramic capacitors. Various types of class II dielectric capacitors with rated voltages from 6.3 V to 100 V, and capacitances from 0.1 μF to 100 μF from different manufactures were used in this study. Fractures in the parts were introduced mechanically and by thermal shock stress. It has been shown that cracking results in relatively minor variations of capacitance and DF. Absorption currents prevail over leakage currents during standard IR measurements at room temperatures, and at high temperatures the intrinsic leakage currents exceed substantially leakage currents caused by cracking thus masking the presence of defects. Analysis of distributions of breakdown voltages in normal capacitors and capacitors with cracks showed that the majority of defective capacitors can pass the DWV testing. New, more effective methods of electrical testing and possible improvement of the existing techniques are discussed.

Design of Insulation Resistance Measurement System for Electrical Steel Sheet Surface Coating

2014 ◽  
Vol 494-495 ◽  
pp. 895-898
Author(s):  
Kan Liu ◽  
Jun Yun Li
Keyword(s):  
Measurement System ◽  
Surface Coating ◽  
Steel Sheet ◽  
Electrical Steel ◽  
High Repetition Rate ◽  
Resistance Measurement ◽  
Insulation Resistance ◽  
Surface Insulation Resistance ◽  
Electrical Steel Sheet ◽  
Measurement Repeatability

The surface coating of insulation resistance is one of the key technical indexes of electrical steel sheet, and one of the important parameters of the products of electrical steel sheet. Nowadays the surface coating of insulation resistance device is relatively heavy, measurement error is relatively large, and measurement repeatability is not good. To solve these problems, we design an insulation resistance measurement system based on Infineon XE166 microcontroller. This article analyzes the measuring principle of silicon steel coating surface insulation resistance and includes the three aspects of mechanical, circuit and software. The experimental results validate the feasibility of this system. The measurement system is stable and reliable, high repetition rate, and has a good application prospect.

scholarly journals DIAGNOSTIC OF THE INSULATION STATE OF THE ASYNCHRONOUS MOTOR AND THE POWER SUPPLY CABLE UNDER CONDITIONS OF LOCAL COMPENSATION

2017 ◽  
Vol 60 (6) ◽  
pp. 536-543
Author(s):  
V. E. Krivonosov
Keyword(s):  
Power Supply ◽  
Reactive Power ◽  
Low Voltage ◽  
Asynchronous Motor ◽  
Reactive Power Compensation ◽  
Discharge Process ◽  
Insulation Resistance ◽  
Effective Measure ◽  
Battery Capacity ◽  
Resistance Value

More than 70 % of the load in metallurgy, mining, gas, and other industries of the CIS consist of asynchronous motors. A relevant objective for all enterprises is to reduce consumption of reactive power in the network and ensuring reliable start of the engine by controlling the resistance value of the insulation. The most effective measure for reactive power compensation is placing the capacitor batteries directly at the points of connection of the asynchronous motor i. e. local reactive power compensation. The aim of the present research was to reduce the cost of production of the enterprise (which provides reactive power compensation), and in the period of technological pause to use the power stored in the capacitor to batteries in order control the changes of resistance value of insulation. After disconnecting the motor from the mains and its stop, the windings is being connected in parallel to the capacitor bank. The discharge of the capacitor is performed in the circuit consisting of the inductance of the motor winding, the integrated insulation resistance and battery capacity. Characteristic features of the transitional discharge process of the capacitor depend on the size of the equivalent circuit elements. The transition process may be aperiodic and periodic in its nature. Aging of motor winding causes a decrease of its impedance. When the magnitude of the insulation resistance reaches a critical value, this causes a change of the nature of the process. The device that has been developed monitors the insulation condition of the motor and the power supply cable during technological pauses without the low voltage power source and additional switching.

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