Most bipolar junction transistors and field-effect transistors (FETs) have three terminals. In the BJT symbol, the base lead is perpendicular to and lands at the midpoint of a short line segment representing the semiconductor substrate. The emitter has an arrowhead embedded in the lead, so the remaining lead has to be the collector. If the […]
Difference between arc-fault circuit interrupters and ground-fault circuit interrupters
Arc-fault circuit interrupters (AFCIs) are sometimes confused with similar appearing ground-fault interrupters, GFCIs, which protect against electric shock. Rather than protecting against electric shock, AFCIs protect buildings and occupants from electrical fire. Internal electronics and operating principles of the two devices are entirely different. A GFCI protects the occupant from electric shock by detecting the […]
When a coronagraph comes in handy
You can think of a coronagraph as having the same effect as a total eclipse of the sun where only its outer edge is visible. It is a telescopic attachment designed to block out the direct light from a star. The early coronagraphs were intended to view the corona of the Sun. But a new […]
Working with fiber optic internet connections
Fiber internet service is often called the gold standard of residential internet connections thanks to the fact that a fiber internet connection can easily provide a 10x speedier connection than ordinary coax cable. Fiber-to-the-Home (FTTH) deployments by Verizon Fios and AT&T Fiber are capable of 4K video conferencing and ultra-fast file uploads. Such connections also […]
Signal jitter and RF receiver sensitivity
Traditional frequency modulation has long been used in broadcast applications, but modern digital communication schemes use various digital versions of FM. Communication parameters for digital communication techniques differ somewhat from those for their analog counterparts. It can be useful to review some of these changes. Perhaps the most basic is communication receiver sensitivity. For purposes […]
Single-sideband modulation and its measurement
The most basic form of amplitude modulation is known as double-sideband AM, so called because mirror-image sidebands are produced above and below the carrier frequency. Early researchers found that they could use simple band-pass filters to eliminate one of the sidebands and even the carrier signal, improving the ratio of information-bearing power to total transmitted […]
Tools: Galileo and the sector
Galileo was born the same year as William Shakespeare. He was a builder or instruments and used them to measure earthly and extraterrestrial phenomena. He published his findings, only to become embroiled in disputes with the religious authorities. In a trial before the Inquisition, he was compelled to recant his views and he spent his […]
Integration and differentiation operations and how they appear on a scope
Differential calculus is the study of rates at which quantities change. To find the derivative of a waveform at a specific point, we draw a tangent line through the point. The slope of the line, Δy/Δx, equals the derivative of the function at that point. Integral calculus quantifies the area bounded by a curve and […]
Online calculators that are handy for EEs
Online calculators have proliferated. Consider that one site dubbed omnicalculator.com now hosts over 1,800 online calculators in various disciplines. But when it comes to electronics and engineering, the pickings are slimmer. Calculatoredge.com provides numerous online calculators for engineers of which a little over 100 are in electronics and electrical engineering. That brings us to Digi-Key […]
Audio measurements and Dolby, dbx noise reduction
Audio engineers in the 1970s became aware that many of the traditional distortion mitigating methods were unsatisfactory. In this context, dbx and Dolby noise reduction systems emerged. Dbx Type I and Type II vastly improved audio fidelity in analog tape reproduction. Dbx-TV is another system component that provides stereo sound for TV systems in the […]
