title: A low frequency supercapacitor circulation technique to improve the efficiency of linear regulators based on LDO ICs

authors: Kularatna, Nihal

subjects: converters

abstract: Linear regulators have output specifications far superior to switch-mode techniques, except for the overall efficiency. This efficiency limitation can be overcome by applying a very low frequency supercapacitor circulation technique at the input side of a low dropout regulator IC. The technique was proven in 12V to 5 V versions, and, can be easily applied to other power supplies such as 5 to 3.3V or 5 to 1.5V versions required by various processors. The paper outlines the concepts and experimental results related to this technique. With the commercial LDO chips available with output current ratings up to 10A, and, thin profile supercapacitors available are with DC voltage ratings from 2.3V to 5.5V, the technique assists developing medium current linear regulators which could compete with present day switch-mode power supplies in efficiency and compactness, maintaining the superior output specifications of a linear regulator.

text: A low frequency supercapacitor circulation technique to improve the efficiency of linear regulators based on LDO ICs Linear regulators have output specifications far superior to switch-mode techniques, except for the overall efficiency. This efficiency limitation can be overcome by applying a very low frequency supercapacitor circulation technique at the input side of a low dropout regulator IC. The technique was proven in 12V to 5 V versions, and, can be easily applied to other power supplies such as 5 to 3.3V or 5 to 1.5V versions required by various processors. The paper outlines the concepts and experimental results related to this technique. With the commercial LDO chips available with output current ratings up to 10A, and, thin profile supercapacitors available are with DC voltage ratings from 2.3V to 5.5V, the technique assists developing medium current linear regulators which could compete with present day switch-mode power supplies in efficiency and compactness, maintaining the superior output specifications of a linear regulator.

year: 2011

title: Balanced diagonals in frequency squares

authors: Cavenagh, Nicholas J.

subjects: Science & Technology

abstract: We say that a diagonal in an array is λ-balanced if each entry occurs λ times. Let L be a frequency square of type F (n; λ); that is, an n ✕ n array in which each entry from {1, 2, …, m=n / λ } occurs  λ times per row and  λ times per column. We show that if m≤3 , L contains a λ -balanced diagonal, with only one exception up to equivalence when m=2. We give partial results for m≥4 and suggest a generalization of Ryser’s conjecture, that every Latin square of odd order has a transversal. Our method relies on first identifying a small substructure with the frequency square that facilitates the task of locating a balanced diagonal in the entire array.

text: Balanced diagonals in frequency squares We say that a diagonal in an array is λ-balanced if each entry occurs λ times. Let L be a frequency square of type F (n; λ); that is, an n ✕ n array in which each entry from {1, 2, …, m=n / λ } occurs  λ times per row and  λ times per column. We show that if m≤3 , L contains a λ -balanced diagonal, with only one exception up to equivalence when m=2. We give partial results for m≥4 and suggest a generalization of Ryser’s conjecture, that every Latin square of odd order has a transversal. Our method relies on first identifying a small substructure with the frequency square that facilitates the task of locating a balanced diagonal in the entire array.

year: 2018

title: Whāia ngā pae o te māramatanga: our horizons of pursuit

authors: Ruru, Jacinta

abstract: In Aotearoa New Zealand there is a growing recognition that Māori engagement and leadership across the science and research sector is essential for addressing national challenges and realising the distinctive contribution of mātauranga Māori to innovation and knowledge creation (Ministry of Education 2013a). To reap the benefits of the nation’s changing demographics and to centre Te Tiriti o Waitangi in society, it is critical that Māori are engaged in research and decision making in all disciplines and in all sectors. This article considers how Ngā Pae o te Māramatanga (NPM), New Zealand’s Māori Centre of Research Excellence, is contributing towards addressing and developing challenges and opportunities at the interface between mātauranga Māori and science. The article traces the contribution of NPM as a positive transformative contributor to research in Aotearoa New Zealand and internationally

text: Whāia ngā pae o te māramatanga: our horizons of pursuit In Aotearoa New Zealand there is a growing recognition that Māori engagement and leadership across the science and research sector is essential for addressing national challenges and realising the distinctive contribution of mātauranga Māori to innovation and knowledge creation (Ministry of Education 2013a). To reap the benefits of the nation’s changing demographics and to centre Te Tiriti o Waitangi in society, it is critical that Māori are engaged in research and decision making in all disciplines and in all sectors. This article considers how Ngā Pae o te Māramatanga (NPM), New Zealand’s Māori Centre of Research Excellence, is contributing towards addressing and developing challenges and opportunities at the interface between mātauranga Māori and science. The article traces the contribution of NPM as a positive transformative contributor to research in Aotearoa New Zealand and internationally

year: 2019