New Dimension

Here's what you need for home theater in the round

3 min read
New Dimension

(US $2000 to $7000)


The consumer electronics industry has so far lined up behind a single 3-D TV methodology—a regular HD screen with an inexpensive infrared-signal emitter on top, though other types of synchronization emitters, including Bluetooth and RF, can also be found. The signal emitter sends out chirps every 8.3 milliseconds that tell "active" 3-D LCD glasses to successively darken the right lens and then the left, and so on. This keeps down the cost of adding 3-D for manufacturers. Make sure your glasses and TV use the same type of signal.

Example: Sony Bravia KDL-HX800
US $2650


($250 and up)

panasonic DMP-BDT350

Photo: Panasonic
Example: Panasonic DMP-BDT350

In December, with the promise of an HDMI cable that would carry as much data as the highest-definition 3-D would require, the Blu-ray Disc Association announced its 3-D specs. That means any 3-D HD Blu-ray player on the market today that sports the 3-D Blu-ray logo will support the highest standard definition for 3-D content—1080p 3-D to both eyes at 240 frames per second—and will also spin regular Blu-ray discs and those stacks of DVDs and CDs in your media cabinet. In addition, some late-model Blu-ray players can upgrade to full HD 3-D in firmware.


(cost varies depending on subscription)

DirectTV 3-D set-top box

Photo: DirecTV
Example: DirecTV 3-D set-top box

The bad news: For at least the next few years, cable and satellite set-top boxes won't match the full HD resolution to each eye that 3-D Blu-ray discs do (1080p). The good news: This bit of hardware probably doesn't need replacing, just a (typically free) firmware upgrade.

Box makers have for the moment pushed to keep their 3-D and 2-D content the same size image with the same number of frames per second. Inevitably, it's 3-D's resolution that suffers. "Side-by-side 3-D" (which DirecTV uses) squishes the images seen by the left and right eye into a standard high-def frame (making the image that each eye sees 960 by 1080 instead of the full-HD 1920 by 1080), while "top/bottom 3-D" does the same trick in the vertical dimension. In both cases, the set-top box splits up the image being transmitted and fills the whole of your TV screen with the left eye's image while syncing with the active glasses to darken the right eye, and then vice versa.


connecting to the TV
($40 each and up)

Belkin HDMI cable

Photo: Belkin
Example: Belkin HDMI cable $40

The cable connecting your 3-D TV to the source of 3-D programming—whether it's a 3-D–enabled Blu-ray player or cable set-top or satellite box—should be a high-speed (1.4) HDMI cable, says Brian Markwalter of the Consumer Electronics Association. Watch out for stores that are still stocking the lower-speed standard (1.3) cables, which should have faded from the market after the new cables came out in the second half of last year. The older cables may not be able to handle the increased data rate of full HD 3-D video.


($150 to $200 per pair)

XpanD x103 3-D glasses

Photo: XpanD
Example: XpanD X103 3-D glasses

With the exception of LG's anomalous LD950 LCD panel—which requires merely the same cheap polarized glasses found in most 3-D movie theaters today—every consumer 3-D television in the marketplace uses active LCD glasses to achieve the optical illusion of depth. Turning each eye's lens dark and transparent again 60 or so times per second—and alternating that with another 60 or so "winks" per second in the other eye—active 3-D glasses give the relatively slow brain the impression of depth from the flat screen. You'll know that 3-D TV has really caught on when high-end eyewear designers start making frames for active 3-D glasses that look as flattering on the face as they make the television's frame look to you.

One 3-D–enabled HD televisionUS $2650
Two HDMI 1.4 cables (TV to Blu-ray; TV to set-top box)$80
One 3-D–enabled Blu-ray player$400
One 3-D–enabled set-top boxFree or monthly surcharge
Four pairs of 3-D glasses$600


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The Inner Beauty of Basic Electronics

Open Circuits showcases the surprising complexity of passive components

5 min read
A photo of a high-stability film resistor with the letters "MIS" in yellow.
All photos by Eric Schlaepfer & Windell H. Oskay

Eric Schlaepfer was trying to fix a broken piece of test equipment when he came across the cause of the problem—a troubled tantalum capacitor. The component had somehow shorted out, and he wanted to know why. So he polished it down for a look inside. He never found the source of the short, but he and his collaborator, Windell H. Oskay, discovered something even better: a breathtaking hidden world inside electronics. What followed were hours and hours of polishing, cleaning, and photography that resulted in Open Circuits: The Inner Beauty of Electronic Components (No Starch Press, 2022), an excerpt of which follows. As the authors write, everything about these components is deliberately designed to meet specific technical needs, but that design leads to “accidental beauty: the emergent aesthetics of things you were never expected to see.”

From a book that spans the wide world of electronics, what we at IEEE Spectrum found surprisingly compelling were the insides of things we don’t spend much time thinking about, passive components. Transistors, LEDs, and other semiconductors may be where the action is, but the simple physics of resistors, capacitors, and inductors have their own sort of splendor.

High-Stability Film Resistor

A photo of a high-stability film resistor with the letters "MIS" in yellow.

All photos by Eric Schlaepfer & Windell H. Oskay

This high-stability film resistor, about 4 millimeters in diameter, is made in much the same way as its inexpensive carbon-film cousin, but with exacting precision. A ceramic rod is coated with a fine layer of resistive film (thin metal, metal oxide, or carbon) and then a perfectly uniform helical groove is machined into the film.

Instead of coating the resistor with an epoxy, it’s hermetically sealed in a lustrous little glass envelope. This makes the resistor more robust, ideal for specialized cases such as precision reference instrumentation, where long-term stability of the resistor is critical. The glass envelope provides better isolation against moisture and other environmental changes than standard coatings like epoxy.

15-Turn Trimmer Potentiometer

A photo of a blue chip
A photo of a blue chip on a circuit board.

It takes 15 rotations of an adjustment screw to move a 15-turn trimmer potentiometer from one end of its resistive range to the other. Circuits that need to be adjusted with fine resolution control use this type of trimmer pot instead of the single-turn variety.

The resistive element in this trimmer is a strip of cermet—a composite of ceramic and metal—silk-screened on a white ceramic substrate. Screen-printed metal links each end of the strip to the connecting wires. It’s a flattened, linear version of the horseshoe-shaped resistive element in single-turn trimmers.

Turning the adjustment screw moves a plastic slider along a track. The wiper is a spring finger, a spring-loaded metal contact, attached to the slider. It makes contact between a metal strip and the selected point on the strip of resistive film.

Ceramic Disc Capacitor

A cutaway of a Ceramic Disc Capacitor
A photo of a Ceramic Disc Capacitor

Capacitors are fundamental electronic components that store energy in the form of static electricity. They’re used in countless ways, including for bulk energy storage, to smooth out electronic signals, and as computer memory cells. The simplest capacitor consists of two parallel metal plates with a gap between them, but capacitors can take many forms so long as there are two conductive surfaces, called electrodes, separated by an insulator.

A ceramic disc capacitor is a low-cost capacitor that is frequently found in appliances and toys. Its insulator is a ceramic disc, and its two parallel plates are extremely thin metal coatings that are evaporated or sputtered onto the disc’s outer surfaces. Connecting wires are attached using solder, and the whole assembly is dipped into a porous coating material that dries hard and protects the capacitor from damage.

Film Capacitor

An image of a cut away of a capacitor
A photo of a green capacitor.

Film capacitors are frequently found in high-quality audio equipment, such as headphone amplifiers, record players, graphic equalizers, and radio tuners. Their key feature is that the dielectric material is a plastic film, such as polyester or polypropylene.

The metal electrodes of this film capacitor are vacuum-deposited on the surfaces of long strips of plastic film. After the leads are attached, the films are rolled up and dipped into an epoxy that binds the assembly together. Then the completed assembly is dipped in a tough outer coating and marked with its value.

Other types of film capacitors are made by stacking flat layers of metallized plastic film, rather than rolling up layers of film.

Dipped Tantalum Capacitor

A photo of a cutaway of a Dipped Tantalum Capacitor

At the core of this capacitor is a porous pellet of tantalum metal. The pellet is made from tantalum powder and sintered, or compressed at a high temperature, into a dense, spongelike solid.

Just like a kitchen sponge, the resulting pellet has a high surface area per unit volume. The pellet is then anodized, creating an insulating oxide layer with an equally high surface area. This process packs a lot of capacitance into a compact device, using spongelike geometry rather than the stacked or rolled layers that most other capacitors use.

The device’s positive terminal, or anode, is connected directly to the tantalum metal. The negative terminal, or cathode, is formed by a thin layer of conductive manganese dioxide coating the pellet.

Axial Inductor

An image of a cutaway of a Axial Inductor
A photo of a collection of cut wires

Inductors are fundamental electronic components that store energy in the form of a magnetic field. They’re used, for example, in some types of power supplies to convert between voltages by alternately storing and releasing energy. This energy-efficient design helps maximize the battery life of cellphones and other portable electronics.

Inductors typically consist of a coil of insulated wire wrapped around a core of magnetic material like iron or ferrite, a ceramic filled with iron oxide. Current flowing around the core produces a magnetic field that acts as a sort of flywheel for current, smoothing out changes in the current as it flows through the inductor.

This axial inductor has a number of turns of varnished copper wire wrapped around a ferrite form and soldered to copper leads on its two ends. It has several layers of protection: a clear varnish over the windings, a light-green coating around the solder joints, and a striking green outer coating to protect the whole component and provide a surface for the colorful stripes that indicate its inductance value.

Power Supply Transformer

A photo of a collection of cut wires
A photo of a yellow element on a circuit board.

This transformer has multiple sets of windings and is used in a power supply to create multiple output AC voltages from a single AC input such as a wall outlet.

The small wires nearer the center are “high impedance” turns of magnet wire. These windings carry a higher voltage but a lower current. They’re protected by several layers of tape, a copper-foil electrostatic shield, and more tape.

The outer “low impedance” windings are made with thicker insulated wire and fewer turns. They handle a lower voltage but a higher current.

All of the windings are wrapped around a black plastic bobbin. Two pieces of ferrite ceramic are bonded together to form the magnetic core at the heart of the transformer.

This article appears in the February 2023 print issue.