My real-life name is Colin Hall. I am a retired electronics engineer and project manager. For many years I did not reveal my real-life identity on Wikipedia so that I could edit here without any concern over what my employers might think. Not that I have ever written anything about any company I worked for, or the products they make, except extremely tangentially. It was just that knowing an employer might be reading might subconciously colour my writing, which I did not want to happen. What I write is entirely for the purpose of improving Wikipedia, and I did not want any other consideration to creep in.
I have written mostly on technical subjects, with a strong bias to the history of technology. Some of my earliest work was on 1920s filter designs which were widely used at one time, but were almost entirely missing from Wikipedia. As this was an area I knew about, it led to my first big tranch of article creation. They weren't my very first articles—I think that was on games and puzzles which also interest me, especially if they are mathematically or logic orientated. But I haven't written anything in that field recently. The majority of electronic/electrical engineering articles that have achieved Featured Article status to date have been written by me.
I have occassionaly dabbled in writing medical articles, especially when there is an electrical aspect to the subject. I am especially attracted to doctors who have carried out bizarre procedures that never caught on. In one year, much to my surprise, I got an award (barnstar type thing) for being one of the top medical editors.
I am also still an active ice skater, but have contributed only a few sentences to Wikipedia in that field.
I will not tread your dusty path and flat,
denoting this and that by this and that,
your world immutable wherein no part,
the little maker has with maker's art.
I bow not yet before the Iron Crown,
nor cast my own small golden sceptre down.
Some editors will put articles on their lists to which they have merely made a small contribution. All the articles and images shown here and on the linked lists have been created by me from scratch, or at most from an insignificant stub.
Zobel invented the m-derived filter and the constant-resistance filter, which remains in use today. With Carson he helped to establish the nature of noise in electric circuits, concluding that—contrary to mainstream belief—it is not even theoretically possible to filter out noise entirely and that noise will always be a limiting factor in what it is possible to transmit. Thus, they anticipated the later work of Claude Shannon, who showed how the theoretical information rate of a channel is related to the noise of the channel.
Analogue filters have played an important part in the development of electronics. Especially in the field of telecommunications, filters have been of crucial importance in a number of technological breakthroughs and have been the source of enormous profits for telecommunications companies. It should come as no surprise, therefore, that the early development of filters was intimately connected with transmission lines. Transmission line theory gave rise to filter theory, which initially took a very similar form, and the main application of filters was for use on telecommunication transmission lines. However, the arrival of network synthesis techniques greatly enhanced the degree of control of the designer.
BBC engineers equalising audio landlines circa 1959 using adjustable Zobel networks
Zobel networks are a type of filter section based on the image impedance design principle. They are named after Otto Zobel of Bell Labs who published a much referenced paper on image filters in 1923. The distinguishing feature of Zobel networks is that the input impedance is fixed in the design independently of the transfer function. This characteristic is achieved at the expense of a much higher component count compared to other types of filter sections.
Zobel networks were formerly widely used in telecommunications to flatten and widen the frequency response of copper land lines, producing a higher quality line from one originally intended for ordinary telephone use. However, as analogue technology has given way to digital they are now little used.
Minimum orbit intersection distance, abbreviated MOID, is a measure used in astronomy to assess collision risk between astronomical objects. It is defined as the distance between the closest points of the osculating orbits of the two bodies in question. Of greatest interest is the risk of a collision with Earth; the MOID between an object and Earth is called Earth MOID. Earth MOID is often listed on comet and asteroid databases such as the Jet Propulsion Laboratory's Small-body Database. However, MOID can be defined with respect to other bodies as well: Jupiter MOID, Venus MOID and so on.
An object is classified as a Potentially Hazardous Object (PHO) – that is, posing a possible risk to Earth – if, among other conditions, its Earth MOID is less than 0.05 AU.
The components of a mechanical filter are all directly analogous to the various elements of an electrical circuit. It is therefore possible use electrical network analysis and filter design techniques on mechanical filters which is a great convenience for electrical engineers in the design of these circuits. Any of the classic frequency responses can be obtained with the right choice of component values.
A Murphy drip is a rectal infusion apparatus to administer the medical procedure of proctoclysis, also known as rectoclysis. During the procedure, an end of the Murphy drip is inserted into the rectum and large quantities of liquid are infused into the rectum drop-by-drop. Prior to fluids or medicines being given intravenously, the Murphy drip and hypodermoclysis were the prime routes to administer fluids such as for replacement when patients could not be fed by mouth. Wisconsin surgeon John Benjamin Murphy introduced the drip method of saline infusion per rectum in the treatment of peritonitis.