Soon afterwards Alexander Graham Bell patented the blast in 1876 (just a few hours advanced of his rival, Elisha Gray), there was an astronomic appeal for his fresh invention. The antecedent bazaar was for the auction of telephones, which came in pairs. It was up to the chump to cord a distinct wire amid them. [...]
Unguided optical signaling has been in use for centuries. Paul Revere used binary optical signaling from the Old North Church just prior to his famous ride. A more modern application is to connect the LANs in two buildings via lasers mounted on their rooftops. Optical coherent signaling using lasers is inherently unidirectional, so each building [...]
For ease of drawing complex circuit diagrams, electronic amplifiers are often symbolized by a simple triangle shape, where the internal components are not individually represented. This symbology is very handy for cases where an amplifier’s construction is irrelevant to the greater function of the overall circuit, and it is worthy of familiarization: The +V and [...]
Our exploration of thyristors begins with a device called the four layer diode, also known as a PNPN diode, or a Shockley diode after its inventor, William Shockley. This is not to be confused with a Schottky diode, that two-layer metal-semiconductor device known for its high switching speed. A crude illustration of the Shockley diode, [...]
To overcome the challenge of creating necessary DC bias voltage for an amplifier’s input signal without resorting to the insertion of a battery in series with the AC signal source, we used a voltage divider connected across the DC power source. To make this work in conjunction with an AC input signal, we “coupled” the [...]
Standing waves at the resonant frequency points of an open- or short-circuited transmission line produce unusual effects. When the signal frequency is such that exactly half wave or some multiple thereof matches the line’s length, the source the load impedance as it is. The following pair of illustrations shows an open-circuited line operating at 1/2 [...]
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