August 19, 2013

Complex simplicity


The HDTV (plasma or LCD) is another confirmation of a perhaps inexorable trend in consumer electronics over the past quarter-century: devices have gotten vastly simpler at the macro level as they've gotten vastly more complex at the micro level.

To start with a simple example: from three (audio/composite/S-Video) to five (audio/component) cables/jacks replaced by a single HDMI. The back of the TV is no longer a spider's web of wires.

The increasingly rare CRT is such an absurdly complex piece of equipment--basically a tiny linear accelerator--that it's amazing it works at all. From both a design and manufacturing standpoint, the LCD screen is incredibly simple by comparison.

The game-changer is that the micro level has been completely automated. Most of the macro assembly tasks are done by robots too. Back in the early days of the semiconductor, transistors were hand-made, just like vacuum tubes.

The planar process (the second great breakthrough in modern electronics, preceded by the transistor and followed by the integrated circuit) made it possible to mass-produce semiconductors using photolithography.

I grew up at the end of the vacuum tube era and dismantled my share of discarded TV sets (and even managed to fix a few). It's truly amazing what electronics engineers could accomplish with a handful of vacuum-tube driven discrete circuits.

A basic B&W set back then had a dozen or so tubes. The typical vacuum tube was the equivalent of two transistors. Your remote control has about a million times as many.

There wasn't a part in a vacuum tube TV you couldn't see with the naked eye, including the stuff inside the vacuum tubes. All of those parts were hand-assembled and quite literally added up to a scalding hot cauldron of energy-eating entropy.

The tuner alone was a two or three-tube local oscillator, frequency mixer and IF amplifier built around a multi-deck rotary switch the size of a gear shift lever. It was a major point of failure, fueling a small industry in cleaning sprays.
Courtesy Wikipedia Commons.

The tuning coils were hand-soldered to the contraption, which had to be bolted to the frame. As you can see in this blast from the past at Phil's Old Radios, even though printed circuit boards were coming into use, a lot of the guts were still hand-wired.

That meant manufacturing televisions was hugely labor-intensive. In inflation-adjusted terms, A 19-inch TV from that era cost almost $2000 in today's dollars!

An LCD TV is simply a specialized laptop with five SKUs: a mainboard, screen, power supply (power brick), remote (instead of a keyboard), and case. Like "white box" PC parts, wholesalers will happily sell them directly to you (preferable in lots of 1000).

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