Equal-Valued Resistive Ladders with Rational Input Resistance

ABSTRACT

Input resistance of a conventional semi-finite equal-valued resistive ladder (EVRL) is irrational. This paper presents EVRL that has rational input resistance, but at the cost of increase in the number of resistances. Expressions for the voltage of any node and the resistance between any two arbitrary nodes for such a ladder are derived. These can be obtained by conventional methods, but they are derived using the difference equation method so that one would know the difference in the two methods.

KEYWORDS:

• Difference equation method
• equal-valued resistive ladder
• input resistance
• ladder

Acknowledgement

The author thanks the reviewer for his help improving the presentation. The author acknowledges with thanks the help rendered by Dr Nandakumar Nambath of IIT Goa for drawing the nice figures.

Additional information

Notes on contributors

T. S. Rathore

T. S. Rathore received B. Sc. (Engg), M.E., and Ph. D. (Electrical Engineering) all from Indore University, Indore. He served SGSITS, Indore (1965–1978), IIT Bombay (1978–2006) and St. Francis Institute of Technology, Borivali (2006–2014) as Dean (R&D). Currently, he is a Visiting Professor at IIT Goa, India, since July 2017. He was a post-doctoral fellow (1983–1985) at the Concordia University, Canada and a visiting researcher at the University of South Australia, Adelaide (March–June 1993). He was an ISTE visiting professor (2005–2007). He has published and presented over 225 research papers. He has authored the book Digital Measurement Techniques, New Delhi: Narosa Publishing House, 1996 and Alpha Science International Pvt. Ltd., UK, 2003 and translated in Russian language in 2004. He was the Guest Editor of the special issue of Journal of IE on Instrumentation Electronics (1992). He is a member on the editorial boards of ISTE National Journal of Technical Education and IETE Journal of Education. Prof. Rathore is a Life Senior Member of IEEE (USA), Fellow of IETE (India) and IE (India), Member of ISTE, Instrument and Computer Societies of India. He has served Mumbai Centre as Secretary, Vice-Chairman and Chairman. He has received IEEE Silver Jubilee Medal, ISTE UP Government National Award (2002) and Maharashtra State National Award (2003), IETE MN Saha Memorial Award, Prof SVC Aiya Memorial Award, BR Batra Memorial Award, Prof K Sreenivasan Memorial Award, KS Krishnan Memorial Award, Hari Ramji Toshniwal Gold Medal Award and best paper awards published in IETE Journal of Education (2011, 2013).