Carrier phase

Light Activated SCR

Like bipolar transistors, SCRs and TRIACs are also manufactured as light-sensitive devices, the action of impinging light replacing the function of triggering voltage. Optically-controlled SCRs are often known by the acronym LASCR, or Light Activated SCR. Its symbol, not surprisingly, looks like this: Optically-controlled TRIACs don’t receive the honor of having their own acronym, but [...]

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Square Wave Pulse Signal Generator

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 [...]

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Common Base Amplifier

Common Base Amplifier: The final transistor amplifier configuration we need to study is the common-base. This configuration is more complex than the other two, and is less common due to its strange operating characteristics. It is called the common base configuration because (DC power source aside), the signal source and the load share the base [...]

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Common Collector Amplifier

Fig – Common Collector Amplifier : Our next transistor configuration to study is a bit simpler in terms of gain calculations. Called the common-collector configuration.It is called the common collector configuration because (ignoring the power supply battery) both the signal source and the load share the collector lead as a common connection point: It should [...]

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Basic Transistor Operation

When a transistor is in the fully-off state (like an open switch), it is said to be cutoff. Conversely, when it is fully conductive between emitter and collector (passing as much current through the collector as the collector power supply and load will allow), it is said to be saturated. These are the two modes [...]

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Transistor Operation

The transistor is a three-layer semiconductor device consisting of either two n- and one p-type layers of material or two p- and one n-type layers of material. The former is called an n-p-n transistor, while the latter is called a p-n-p transistor. Both are shown in Fig. 3.2 with the proper dc biasing. The dc [...]

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Organic Light Emitting Diodes

The increasing use of digital displays in calculators, watches, and all forms of instrumentation has contributed to the current extensive interest in structures that will emit light when properly biased. The two types in common use today to perform this function are the light-emitting diode (LED) and the liquid crystal display (LCD). Since the LED [...]

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Pulse Waveforms

Our analysis thus far has been limited to alternating waveforms that vary in a sinusoidal manner. This chapter will introduce the basic terminology associated with the pulse waveform and will examine the response of an R-C circuit to a square wave input. The importance of the pulse waveform to the electrical/electronics industry cannot be overstated. [...]

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Band Pass Filters

A band pass filter works to screen out frequencies that are too low or too high, giving easy passage only to frequencies within a certain range. Band-pass filters can be made by stacking a low-pass filter on the end of a high-pass filter, or vice versa. The System level block diagram of a band-pass filter [...]

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