Monday, 4 March 2013

Current source

A current source is an electronic circuit that delivers or absorbs an electric current which is independent of the voltage across it. A current source is the dual of a voltage source. The term constant-current sink is sometimes used for sources fed from a negative voltage supply. Figure 1 shows the schematic symbol for an ideal current source, driving a resistor load. There are two types. An independent current source sources or sinks a constant current. A dependent current source delivers a current which is proportional to some other voltage or current in the circuit

Monday, 16 July 2012

Open source

In production and development, open source is a philosophy, or pragmatic methodology that promotes free redistribution and access to an end product's design and implementation details. Before the phrase open source became widely adopted, developers and producers used a variety of phrases to describe the concept; open source gained hold with the rise of the Internet, and the attendant need for massive retooling of the computing source code.Opening the source code enabled a self-enhancing diversity of production models, communication paths, and interactive communities. The open-source software movement was born to describe the environment that the new copyright, licensing, domain, and consumer issues created.

The open-source model includes the concept of concurrent yet different agendas and differing approaches in production, in contrast with more centralized models of development such as those typically used in commercial software companies. A main principle and practice of open-source software development is peer production by bartering and collaboration, with the end-product, source-material, "blueprints", and documentation available at no cost to the public. This is increasingly being applied in other fields of endeavor, such as biotechnology.

Monday, 11 June 2007

Free Software, Free Society

I just spent the Queen's Birthday long weekend at our (extended) family's beach shack (circa 1920s). Three days with no interweb, *sob*, so I spent most of the time doing schoolwork...yawn. But in the downtime, I read two books: Antony Beevor's Downfall: Berlin 1945, which is an excellent history book: I can't wait to read his one on Stalingrad. The second was Richard M. Stallman's Free Software, Free Society, and I must say I have been tremendously reformed by reading this book, and I recommend everyone read it: right here, for free (PDF ~ 3mb). It's really changed my thinking about Free Software, and it will change your's too.