Development of Professional-Grade Passive Components in India

Abstract

Vigorous efforts have been made since early seventies to establish sources of professional grade electronic components for defence applications. As a step in this direction, a number of Joint Service Specification were framed.CIL has provided the bulk of testing to assess the conformance of the indigenous components to the various JSS. This has resulted in locating a No. of sources for a variety of passive components to the approved list for defence use. There were very few manufacturers of Carbon Film Resistors, Ceramic and Electrolytic Tantalum Capacitors, Circuit Breakers, Switches and Relays prior to 1974. However, at present the sources have been established to meet requirement of the JSS for passive components like carbon and metal Film Resistors. Ceramic Mica Polystyrene, Metallised Polyester, Aluminium Electrolytic and Tantalum Electrolytic Capacitors, different type of Switches, relays, circuit breakers, Fuse holders, Fuse links and Ferrites etc. Besides Qualification Approval project on behalf of LCSO, CIL has also undertaken testing of No. of indigenous products from large No. of manufacturers where they are not covered by the pattern-styles of JSS, but are required to be used in the equipment for defence applications. As a result of evaluation of these products, No. of additional sources have also been established for the above components to supplement the items not covered under JSS, until such time approved sources are located.Approval of component to JSS have been achieved with improvements in products for the failure noticed during the initial testing. For this CIL has helped the manufacturers to improve their products by providing them feedback about the quality of their product in the form of failure analysis and suggestions and also testing their product on payment to assess its quality before submission for Qualification Approval. With concerted efforts of manufacturers and testing agency the quality of approved sources in respect of resistors, ceramic capacitors, relay and switches have improved considerably and no significant failures have been noticed for these items when subjected to Qualification Approval during last 3 years. Number of sources have also been established for polystyrene and metallised polyster capacitors after overcoming initial failures mostly after damp heat, damp-heat steady-state and life electrical tests in insultation resistance, fans and change of capacitance value. Failure of relays were mostly in contact bounce test, for circuit breakers in tripping and over load test for the fuse link in over load test and fuse holders in insultation resistance test. Corrosion was observed in number of cases in salt corrosion test.A large number of indigenous products have also been tested in CIL to check their conformance to Indian Standard Specifications either on request of manufacturers or on behalf of ISI, P and T etc leading to recognition of sources capable of meeting requirement of Indian Standard Specifications.