Prior to Albert Einstein’s two theories of relativity, space was conceived as an inert, albeit multidimensional, frame of reference. It did not appear to move, but instead objects including earth moved through it. In the wake of Einstein’s revolution, physicists and eventually the general public came to see that space, along with time, was a […]
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Where to get free training in electronics and instrumentation
EdX began in May, 2012 as a not-for-profit joint venture of the Massachusetts Institute of Technology (MIT) and Harvard University. Currently, many top-level colleges and universities have come on board. Branded as a massive open online course (MOOC) provider, it is open to anyone who wants to take any of over 500 courses online. Prominent […]
Basic electronic troubleshooting from circuits to stereos
When electronics fails to operate properly, the engineer or technician must locate the fault and fix the problem. Often the actual repair is relatively easy but the initial diagnosis may be difficult. Certain diagnostic procedures are unique to electronic systems but often the logic and reasoning are no different than in the diagnosis of a […]
Basics of dark energy and dark matter
Observations beginning in the 1990s support the idea that the universe is expanding at an accelerating rate. No longer considered just a hypothesis, this accelerating expansion is now an accepted fact. But a major leap of faith is still required for it to actually work. Suppose the rate of expansion of the universe depended upon […]
When electric motors need over-load protection
The National Electrical Code (NEC) covers non-utility electrical installations from the point of view of safety. One primary focus of NEC articles is over-current protection and the related concept of ampacity. NEC Chapter three contains extensive tables for sizing electrical conductors in many intended applications. The implication of these tables is that choosing the correct […]
From the camera obscura to CCD and CMOS image sensors
Long before photography, there was the camera obscura. It consisted of a closed, darkened room, eventually reduced to the size of a small box, with a pinhole opening in one wall. At the opposite side on a screen would be projected an inverted image from outside. At first the only way to preserve the image […]
VIDEO: Oscilloscope Cursor Basics
Cursor bracketing of waveform segments in the Tektronix MDO 3104 oscilloscope.
TCP packet and IP packet switching
Packet switching is the fundamental protocol that lets the Internet and Local Area Networks function in their decentralized, user-directed, constantly evolving ways. The idea is to group data to be transmitted into discrete blocks known as packets. Because information is confined to discrete regions that have defined beginnings and endings, they can coexist without mixing […]
Basics of copper and aluminum conductors
When a positive anode and a negative cathode are attached at either end of a conductor, electrons flow from the negative end toward the positive end as the charges approach a state of equilibrium. The current diminishes as the difference between the charge levels grows smaller, unless the charges are replenished via chemical action, as […]
Basics of using a Spice simulation
Because they contain millions or even billions of microscopic components etched onto a silicon substrate, it is not feasible to breadboard integrated circuits prior to manufacture. And yet it would not be good policy to do a production run of ICs without a high degree of certainty that they will function as intended both internally […]