Analog {if 0}- Education

2-wire analog outputs with precision DACs

This calculator computes the resonant frequency of a tank circuit

A third variation on the counter-DAC-based converter theme is, in my estimation, the most elegant. Instead of a regular “up” counter driving the DAC, this circuit uses an up/down counter. The counter is continuously clocked, and the up/down control line is driven by the output of the comparator. So, when the analog input signal exceeds the DAC output, the counter goes into the “count up” mode. When the

In our study of AC circuits thus far, we’ve explored circuits powered by a single-frequency sine voltage waveform. In many applications of electronics, though, single-frequency signals are the exception rather than the rule. Quite often we may encounter circuits where multiple frequencies of voltage coexist simultaneously. Also, circuit waveforms may be something other than sine-wave shaped, in which case we call them non-sinusoidal waveforms. Additionally, we may encounter situations

Inductors have the exact opposite characteristics of capacitors. Whereas capacitors store energy in an electric field (produced by the voltage between two plates), inductors store energy in a magnetic field (produced by the current through wire). Thus, while the stored energy in a capacitor tries to maintain a constant voltage across its terminals, the stored energy in an inductor tries to maintain a constant current through its windings. Because of

While the C-B (common-base) amplifier is known for wider bandwidth than the C-E (common-emitter) configuration, the low input impedance (10s of Ω) of C-B is a limitation for many applications. The solution is to precede the C-B stage by a low gain C-E stage which has moderately high input impedance (kΩs). The stages are in a cascode configuration stacked in series, as opposed to cascaded for a standard amplifier chain. �

Bipolar Junction Transistor or BJT Current Mirror An often-used circuit applying the bipolar junction transistor is the so-called current mirror, which serves as a simple current regulator, supplying nearly constant current to a load over a wide range of load resistances. We know that in a transistor operating in its active mode, collector current is equal to base current multiplied by the ratio β. We also know that the ratio between

All About Contactors When a relay is used to switch a large amount of electrical power through its contacts, it is designated by a special name: contactor. Contactors typically have multiple contacts, and those contacts are usually (but not always) normally-open, so that power to the load is shut off when the coil is de-energized. Perhaps the most common industrial use for contactors is the control of electric motors. The

If we connect the output of an op-amp to its inverting input and apply a voltage signal to the noninverting input, we find that the output voltage of the op-amp closely follows that input voltage (I’ve neglected to draw in the power supply, +V/-V wires, and ground symbol for simplicity): As Vin increases, Vout will increase in accordance with the differential gain. However, as Vout increases, that output

In the last section, we learned what would happen in simple resistor-only and capacitor-only AC circuits. Now we will combine the two components together in series form and investigate the effects. Series capacitor circuit: voltage lags current by 0° to 90°. Impedance Calculation The resistor will offer 5 Ω of resistance to AC current regardless of frequency, while the capacitor will offer 26.5258 Ω of reactance to AC current at 60 Hz. Because the resistor’s resistance

Bipolar junction transistors (Also known as BJTs) can be used as an amplifier, filter, rectifier, oscillator, or even a switch, which we cover an example in the first section. The transistor will operate as an amplifier or other linear circuit if the transistor is biased into the linear region. The transistor can be used as a switch if biased in the saturation and cut-off regions. This allows current to flow

PARTS AND MATERIALS Four 6 volt batteries Dual operational amplifier, model TL082 recommended (Radio Shack catalog # 276-1715) One NPN power transistor in a TO-220 package—(Radio Shack catalog # 276-2020 or equivalent) One PNP power transistor in a TO-220 package—(Radio Shack catalog # 276-2027 or equivalent) One 1N914 switching diode (Radio Shack catalog # 276-1620) One capacitor, 47 µF electrolytic, 35 WVDC (Radio Shack catalog # 272-1015 or equivalent) Two capacitors, 0.22 µF, non-polarized (Radio Shack catalog # 27

The purpose of the parallel-in/ parallel-out shift register is to take in parallel data, shift it, then output it as shown below. A universal shift register is a do-everything device in addition to the parallel-in/ parallel-out function. Above we apply four bit of data to a parallel-in/ parallel-out shift register at DA DB DC DD. The mode control, which may be multiple inputs, controls parallel loading vs shifting. The mode

SCRs are unidirectional (one-way) current devices, making them useful for controlling DC only. If two SCRs are joined in back-to-back parallel fashion just like two Shockley diodes were joined together to form a DIAC, we have a new device known as the TRIAC: (Figure below) The TRIAC SCR equivalent and, TRIAC schematic symbol Because individual SCRs are more flexible to use in advanced control systems, these are more commonly seen

What Is an Instrumentation Amplifier? An instrumentation amplifier allows an engineer to adjust the gain of an amplifier circuit without having to change more than one resistor value. Compare this to the differential amplifier, which we covered previously, which requires the adjustment of multiple resistor values. The so-called instrumentation amplifier builds on the last version of the differential amplifier to give us that capability: Understanding the Instrumentation Amplifier Circuit This

By definition, a low-pass filter is a circuit offering easy passage to low-frequency signals and difficult passage to high-frequency signals. There are two basic kinds of circuits capable of accomplishing this objective, and many variations of each one: The inductive low-pass filter in (Figure below) and the capacitive low-pass filter in (Figure also below). Inductive Low-Pass Filter Inductive low-pass filter The inductor’s impedance increases with increasing frequency. This high

Analog circuits are circuits dealing with signals free to vary from zero to full power supply voltage. This stands in contrast to digital circuits, which almost exclusively employ “all or nothing” signals: voltages restricted to values of zero and full supply voltage, with no valid state in between those extreme limits. Analog circuits are often referred to as linear circuits to emphasize the valid continuity of signal range forbidden in

Learning Objectives Rheostat use Wiring a potentiometer as a rheostat Simple motor speed control Use of voltmeter over ammeter to verify a continuous circuit Parts and Materials 6-volt battery Potentiometer, single turn, 5 kΩ, linear taper (Radio Shack catalog # 271-1714) Small “hobby” motor, permanent-magnet type (Radio Shack catalog # 273-223 or equivalent) For this experiment, you will need a relatively low-value potentiometer, certainly not more than 5 kΩ. Cross-References Lessons In Electric Circuits,

This chapter will cover the physics behind the operation of semiconductor devices and show how these principles are applied in several different types of semiconductor devices. Subsequent chapters will deal primarily with the practical aspects of these devices in circuits and omit theory as much as possible.

We're in Chapter 11 and we'll be looking at the subjection of operational amplifiers and circuits and they're commonly referred to as “op amps” for short. We'll be looking at this particular section, 11.1, in three different sections and so we're starting out with A. Introduction: An operational amplifier (op amp) refers to an integrated circuit having well-defined operating characteristics. We will be looking at those operating characteristics. A single IC may

Reactive Power We know that reactive loads such as inductors and capacitors dissipate zero power, yet the fact that they drop voltage and draw current gives the deceptive impression that they actually do dissipate power. This “phantom power” is called reactive power, and it is measured in a unit called Volt-Amps-Reactive (VAR), rather than watts. The mathematical symbol for reactive power is (unfortunately) the capital letter Q. True Power The