Analog {if 0}- Education

2-wire analog outputs with precision DACs

In many circuit applications, we encounter components connected together in one of two ways to form a three-terminal network: the “Delta,” or Δ (also known as the “Pi,” or π) configuration, and the “Y” (also known as the “T”) configuration. It is possible to calculate the proper values of resistors necessary to form one kind of network (Δ or Y) that behaves identically to the other kind, as analyzed from the terminal connections

Real operational amplifiers have some imperfections compared to an “ideal” model. A real device deviates from a perfect difference amplifier. One minus one may not be zero. It may have have an offset like an analog meter which is not zeroed. The inputs may draw current. The characteristics may drift with age and temperature. Gain may be reduced at high frequencies, and phase may shift from input to output. These

In this circuit, three resistors receive the same amount of current (4 amps) from a single source. Calculate the amount of voltage “dropped” by each resistor, as well as the amount of power dissipated by each resistor:

We're in our final op amp applications, and we will be looking at a voltage comparator. A voltage comparator has two analogue input and one digital output, so if we looked at our op amp, we would have an input here, an input here, and we would have an output. The output will be a digital output, it will need to be a high or a low, and there will

PARTS AND MATERIALS One 12AX7 dual triode vacuum tube Two power transformers, 120VAC step-down to 12VAC (Radio Shack catalog # 273-1365, 273-1352, or 273-1511). Bridge rectifier module (Radio Shack catalog # 276-1173) Electrolytic capacitor, at least 47 µF, with a working voltage of at least 200 volts DC. Automotive ignition coil Audio speaker, 8 Ω impedance Two 100 kΩ resistors One 0.1 µF capacitor, 250 WVDC (Radio Shack catalog # 272-1053) “Low-voltage AC power supply” as shown in AC Experiments

A transistor is a linear semiconductor device that controls current with the application of a lower-power electrical signal. Transistors may be roughly grouped into two major divisions: bipolar and field-effect. In the last chapter, we studied bipolar transistors, which utilize a small current to control a large current. In this chapter, we’ll introduce the general concept of the field-effect transistor—a device utilizing a small voltage to control current�

No text on electrical metering could be called complete without a section on bridge circuits. These ingenious circuits make use of a null-balance meter to compare two voltages, just like the laboratory balance scale compares two weights and indicates when they’re equal. Unlike the “potentiometer” circuit used to simply measure an unknown voltage, bridge circuits can be used to measure all kinds of electrical values, not the least of

Another strategy for addressing the problem of secondary electrons being attracted by the screen was the addition of a fifth wire element to the tube structure: a suppressor. These five-element tubes were naturally called pentodes. The suppressor was another wire coil or mesh situated between the screen and the plate, usually connected directly to ground potential. In some pentode tube designs, the suppressor was internally connected to the cathode so

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). See Figure below. The stages are in a cascode configuration, stacked in series, as opposed to cascaded for a

PARTS AND MATERIALS High-quality “closed-cup” audio headphones Headphone jack: female receptacle for headphone plug (Radio Shack catalog # 274-312) Small step-down power transformer (Radio Shack catalog # 273-1365 or equivalent, using the 6-volt secondary winding tap) Two 1N4001 rectifying diodes (Radio Shack catalog # 276-1101) 1 kΩ resistor 100 kΩ potentiometer (Radio Shack catalog # 271-092) Two “banana” jack style binding posts, or other terminal hardware, for connection to potentiometer circuit (Radio Shack catalog # 274-662 or

PARTS AND MATERIALS Low-voltage AC power supply Two capacitors, 0.1 µF each, non-polarized (Radio Shack catalog # 272-135) Two 27 kΩ resistors I recommend ceramic disk capacitors because they are insensitive to polarity (non-polarized), inexpensive, and durable. Avoid capacitors with any kind of polarity marking, as these will be destroyed when powered by AC! CROSS-REFERENCES Lessons In Electric Circuits, Volume 2, chapter 1: “Basic AC Theory” Lessons In Electric Circuits, Volume 2, chapter 4: “Reactance and Impedance�

What is Rectification? Now we come to the most popular application of the diode: rectification. Simply defined, rectification is the conversion of alternating current (AC) to direct current (DC). This involves a device that only allows one-way flow of electrons. As we have seen, this is exactly what a semiconductor diode does. The simplest kind of rectifier circuit is the half-wave rectifier. It only allows one half of an AC

If at all possible, shut off the power to a circuit before performing any work on it. You must secure all sources of harmful energy before a system may be considered safe to work on. In industry, securing a circuit, device, or system in this condition is commonly known as placing it in a Zero Energy State. The focus of this lesson is, of course, electrical safety. However, many of

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

On this page, we’ll outline the three principles you should understand regarding series circuits: Current: The amount of current is the same through any component in a series circuit. Resistance: The total resistance of any series circuit is equal to the sum of the individual resistances. Voltage: The supply voltage in a series circuit is equal to the sum of the individual voltage drops. Let’s take a look

Resonance in a Tank Circuit A condition of resonance will be experienced in a tank circuit when the reactance of the capacitor and inductor are equal to each other. Because inductive reactance increases with increasing frequency and capacitive reactance decreases with increasing frequency, there will only be one frequency where these two reactances will be equal. Example: Simple parallel resonant circuit (tank circuit). In the above circuit, we have a 10 �

Suppose we had a simple one-battery, one-lamp circuit controlled by a switch. When the switch is closed, the lamp immediately lights. When the switch is opened, the lamp immediately darkens: (Figure below) Lamp appears to immediately respond to switch. Actually, an incandescent lamp takes a short time for its filament to warm up and emit light after receiving an electric current of sufficient magnitude to power it, so the effect

Anyone who’s studied geometry should be familiar with the concept of a theorem: a relatively simple rule used to solve a problem, derived from a more intensive analysis using fundamental rules of mathematics. At least hypothetically, any problem in math can be solved just by using the simple rules of arithmetic (in fact, this is how modern digital computers carry out the most complex mathematical calculations: by repeating many

Typically, complex circuits are not arranged in nice, neat, clean schematic diagrams for us to follow. They are often drawn in such a way that makes it difficult to follow which components are in series and which are in parallel with each other. The purpose of this section is to show you a method useful for redrawing circuit schematics in a neat and orderly fashion. Like the stage-reduction strategy for

JFETs, like bipolar transistors, are able to “throttle” current in a mode between cutoff and saturation called the active mode. To better understand JFET operation, let’s set up a SPICE simulation similar to the one used to explore basic bipolar transistor function: jfet simulation vin 0 1 dc 1 j1 2 1 0 mod1 vammeter 3 2 dc 0 v1 3 0 dc .model mod1 njf .dc v1 0 2 0.05 .plot dc i(vammeter) .end Note that the transistor labeled “Q1” in