Versatile Linear and Digital Optocouplers to Reduce Noise and Ground Loop Errors in Measurements

Abstract

The paper describes design details of low-cost, versatile, linear as well as digital optocoupler circuits used to reduce noise and ground loop errors in measurements. A detailed description of a linear optocoupler circuit for providing galvanic isolation between photodiode signal conditioner ground and the data logger ground is given. We also report use of two single-channel high-speed digital optocouplers to communicate through RS232 protocol isolating the ground of the devices in the detection region of the Cs fountain frequency standard being developed at NPL India. These isolators are versatile, affordable, and give very good results.

Keywords:

• Galvanic isolation
• Ground loops
• Optocoupler

Additional information

Notes on contributors

Aishik Acharya

Aishik Acharya received his Bachelor of Technology (B-Tech) degree in Electronics and Communication Engineering from West Bengal University of Technology, India, in 2009. He has received M-Tech degree in Electronics and Communication Engineering (Specialization in Microwaves) from University of Burdwan, Burdwan, India in 2011. Presently he is working CSIR-National Physical Laboratory as Senior Project Fellow in the field of development of electronic subsystem for Cs Atomic Fountain Clock development. E-mail: [email protected]

Rahul Kumar

Rahul Kumar received his Bachelor of Technology (B.Tech) degree in Electronics and Communication Engineering from Uttar Pradesh Technical University, India, in 2010. After completing graduation, he joined the Time and Frequency Division of National Physical Laboratory, New Delhi, India, as a Project Assistant. Presently, he is working in Ericsson India Pvt. Ltd. as a Engineer-Network Consulting. E-mail: [email protected]

Subhajit Banerjee Purnapatra

Subhajit Banerjee Purnapatra received his Bachelor of Technology (B.Tech) degree in Electronics Engineering-from Indian School of Mines, Dhanbad, India, in 2010. Following his graduation, he joined the Time and Frequency Division of National Physical Laboratory, New Delhi, India, as a project assistant and contributed towards research and development of the electronic and control sub-systems for the Cesium Atomic Fountain Clock project. He is presently pursuing his M.Sc. (Engg.) degree from the Instrumentation & Applied Physics department of the Indian Institute of Science, Bangalore, India, working on biophotonics and nano-scale imaging. E-mail: [email protected]

Kavindra Pant

Kavindra Pant received his M.Sc. degree from Agra University, U. P. in 1972. He joined CSIR-CEERI, Pilani in 1980 and was involved development of power projects, electronic circuits etc. till 2005. He joined NPL in 2005 and contributed in the development of Electronic circuits for Cesium Atomic Fountain Clock project till his superannuation in June, 2012 as Senior Principal Scientist. E-mail: [email protected]

Suchi Yadav

Suchi Yadav received Diploma in Electronics & Communication in the July 2003.After that she recieved her B.E.degree in Electronics & Communication from IETE ( Institute of Electronics & Telecommunication Engineers) New Delhi in year 2010. She has joined the CSIR National Physical Laboratory in June 2009 as Technical Associate in Time & Frequency Division. She is engaged now in the research & development of Primary Cs Atomic Frquency Standard.She is working in the area of electronic circuitry development. She is lifetime corporate member of Instititute of Electronics & Telecommunication Engineers. E-mail: [email protected]

Poonam Arora

Poonam Arora received her B.Sc. degree from Kurukshetra University, Haryana in 2000. She received M.Sc. (Physics) and M.Tech. (Applied Optics) degrees from IIT Delhi in 2002 and 2004, respectively, and Ph.D. degree from Technical University of Darmstadt, Germany in 2007. She is a Scientist at CSIR-NPL since 2009 and is currently working in the area of atomic clocks. E-mail: [email protected]

Amitava Sen Gupta

Amitava Sen Gupta rec eived the M.Sc. and Ph.D. degrees in Physics from the University of Delhi, India, in 1974 and 1980, respectively. His Ph.D. work involved experimental and theoretical studies of traveling ionospheric disturbances using satellites. He joined the CSIR - National Physical Laboratory in January 1979. Presently he is a Scientist-H/ Outstanding Scientist and the Head of the Time & Frequency Division. E-mail: [email protected]