Analog Education

2-wire analog outputs with precision DACs

Most students of electricity begin their study with what is known as direct current (DC), which is electricity flowing in a constant direction, and/or possessing a voltage with constant polarity. DC is the kind of electricity made by a battery (with definite positive and negative terminals), or the kind of charge generated by rubbing certain types of materials against each other. Alternating Current vs Direct Current As useful and

Learn About L/R Time Constants It is often perplexing to new students of electronics why the time-constant calculation for an inductive circuit is different from that of a capacitive circuit. For a resistor-capacitor circuit, the time constant (in seconds) is calculated from the product (multiplication) of resistance in ohms and capacitance in farads: τ=RC. However, for a resistor-inductor circuit, the time constant is calculated from the quotient (division) of

Don’t just sit there! Build something!! Learning to mathematically analyze circuits requires much study and practice. Typically, students practice by working through lots of sample problems and checking their answers against those provided by the textbook or the instructor. While this is good, there is a much better way. You will learn much more by actually building and analyzing real circuits, letting your test equipment provide the “answers” instead

What Is the Skin Effect? As previously mentioned, the skin effect is where alternating current tends to avoid travel through the center of a solid conductor, limiting itself to conduction near the surface. This effectively limits the cross-sectional conductor area available to carry alternating electron flow, increasing the resistance of that conductor above what it would normally be for direct current: (Figure below) Skin effect: skin depth decreases with increasing

The first, and perhaps most important, the relationship between current, voltage, and resistance is called Ohm’s Law, discovered by Georg Simon Ohm and published in his 1827 paper, The Galvanic Circuit Investigated Mathematically. Voltage, Current, and Resistance An electric circuit is formed when a conductive path is created to allow electric charge to continuously move. This continuous movement of electric charge through the conductors of a circuit is called a

The SPICE circuit simulation program provides for modeling diodes in circuit simulations. The diode model is based on characterization of individual devices as described in a product data sheet and manufacturing process characteristics not listed. Some information has been extracted from a 1N4004 data sheet in Figure below. Data sheet 1N4004 excerpt, after [DI4]. The diode statement begins with a diode element name which must begin with “d” plus optional

Instrumentation is a field of study and work centering on measurement and control of physical processes. These physical processes include pressure, temperature, flow rate, and chemical consistency. An instrument is a device that measures and/or acts to control any kind of physical process. Due to the fact that electrical quantities of voltage and current are easy to measure, manipulate, and transmit over long distances, they are widely used to

Let’s analyze a simple series circuit, determining the voltage drops across individual resistors: Determine the Total Circuit Resistance From the given values of individual resistances, we can determine a total circuit resistance, knowing that resistances add in series: Use Ohm’s Law to Calculate Electron Flow From here, we can use Ohm’s Law (I=E/R) to determine the total current, which we know will be the same

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

If you’ve ever witnessed a lightning storm, you’ve seen electrical hysteresis in action (and probably didn’t realize what you were seeing). The action of strong wind and rain accumulates tremendous static electric charges between cloud and earth, and between clouds as well. Electric charge imbalances manifest themselves as high voltages, and when the electrical resistance of air can no longer hold these high voltages at bay, huge

Parts and Materials Operational amplifier, model 1458 or 353 recommended (Radio Shack catalog # 276-038 and 900-6298, respectively) Three 6 volt batteries Two 10 kΩ potentiometers, linear taper (Radio Shack catalog # 271-1715) One light-emitting diode (Radio Shack catalog # 276-026 or equivalent) One 330 Ω resistor One 470 Ω resistor This experiment only requires a single operational amplifier. The model 1458 and 353 are both “dual” op-amp units, with two complete amplifier circuits housed in the same 8-pin DIP package. I recommend

The circuits in the figure below are known as clampers or DC restorers. The corresponding netlist is also in the figure below. These circuits clamp a peak of a waveform to a specific DC level compared with a capacitively coupled signal which swings about its average DC level (usually 0V). If the diode is removed from the clamper, it defaults to a simple coupling capacitor– no clamping. What is Clamp

∫f(x) dx Calculus alert! Calculus is a branch of mathematics that originated with scientific questions concerning rates of change. The easiest rates of change for most people to understand are those dealing with time. For example, a student watching their savings account dwindle over time as they pay for tuition and other expenses is very concerned with rates of change (dollars per year being spent). In calculus, we have

De Forest’s Audion tube came to be known as the triode tube because it had three elements: filament, grid, and plate (just as the “di” in the name diode refers to two elements, filament, and plate). Later developments in diode tube technology led to the refinement of the electron emitter: instead of using the filament directly as the emissive element, another metal strip called the cathode could be heated

We're in Section 10-4 and this will be split into sections A and B. A will look at digital applications and B will look at analog applications. We're going to limit ourselves to just looking at the applications within this particular chapter. Entire books have been written on transistor applications because there are just so many of them. We're just going to be looking at just a small sampling of

Thevenin’s Theorem states that it is possible to simplify any linear circuit, no matter how complex, to an equivalent circuit with just a single voltage source and series resistance connected to a load. The qualification of “linear” is identical to that found in the Superposition Theorem, where all the underlying equations must be linear (no exponents or roots). If we’re dealing with passive components (such as resistors, and

The Q factor of a series inductive circuit is given by the following equation: Q = XL Rseries Likewise, we know that inductive reactance may be found by the following equation: XL = 2 πf L We also know that the resonant frequency of a series LC circuit is given by this equation: fr = 1 2 π √ LC Through algebraic substitution, write an equation that gives the Q factor of a series resonant LC circuit exclusively

Since complex numbers are legitimate mathematical entities, just like scalar numbers, they can be added, subtracted, multiplied, divided, squared, inverted, and such, just like any other kind of number. Some scientific calculators are programmed to directly perform these operations on two or more complex numbers, but these operations can also be done “by hand.” This section will show you how the basic operations are performed. It is highly recommended that

PARTS AND MATERIALS Two 6-volt batteries Four NPN transistors—models 2N2222 or 2N3403 recommended (Radio Shack catalog # 276-1617 is a package of fifteen NPN transistors ideal for this and other experiments) Two PNP transistors—models 2N2907 or 2N3906 recommended (Radio Shack catalog # 276-1604 is a package of fifteen PNP transistors ideal for this and other experiments) Two 10 kΩ potentiometers, single-turn, linear taper (Radio Shack catalog # 271-1715) One 270 kΩ resistor Three 100

The invention of the bipolar transistor in 1948 ushered in a revolution in electronics. Technical feats previously requiring relatively large, mechanically fragile, power-hungry vacuum tubes were suddenly achievable with tiny, mechanically rugged, power-thrifty specks of crystalline silicon. This revolution made possible the design and manufacture of lightweight, inexpensive electronic devices that we now take for granted. Understanding how transistors function is of paramount importance to anyone interested in understanding modern electronics.