How the Clapper Works

Clap-on! Clap-off!
Clap-on! Clap-off!

When 1980s comedians weren't making fun of airline food, they could usually be heard taking a dig at the Clapper. After all, 20 years after its release, the Clapper's infamous "clap-on, clap-off" television ad remains seared into public memory. In only 30 seconds of low-budget advertising, the TV-watching world was first introduced to a product that appealed to both seniors and couch potatoes alike.

First released in 1985, the Clapper allows its user to activate up to two appliances using sequences of claps. Two claps, and you can turn on a lamp. Three claps, and you can switch on a TV. The Clapper works on lights, radios, TVs, rotating disco balls -- anything that can be plugged into one of the Clapper's two electrical outlets. For only $20, a bundle of basic electronics had rendered the manual light switch obsolete. And almost overnight, a cheesy sound-activated product became a mainstay of American pop culture.

The device was built on the notion that remote controls weren't nearly convenient enough. Sure, they allowed people to operate appliances without getting up, but what if you had to get up to go find the remote control?

Today, you may be more likely to see the Clapper at a garage sale than a wall outlet. However, the Clapper era is far from over. Tens of thousands of Clappers continue to be sold every year. Produced by the San Francisco-based makers of the Chia Pet and the Ove Glove, the product remains alive and well and can still be seen on store shelves during the holiday season of October through December. The rest of the year, Clapper enthusiasts have to track down the product online.

We'll take a look at the sordid origins of the Clapper, the future of the device and even how to properly use your Clapper (it requires more than just clapping). But first, we'll learn how a small plastic box uses applause to turn things on.


Mechanics of the Clapper

The inner workings of the Clapper
The inner workings of the Clapper

Electronically speaking, the Clapper is not that complicated. Sound-activated toys have existed as far back as the 1950s. However, the brilliance of the Clapper is that it's able to distinguish between different sounds -- and it does so with only a few dollars worth of electronics. Crack open a standard Clapper, and you'll see little more than a microphone, an electronic sound filter and two electrical switches.

The microphone, mounted at the front of the device, is always tuned in to the surrounding environment. Every sound that hits the Clapper is "heard" by the microphone, turned into an electrical signal and sent to the electronic sound filter.

The filter's job is to determine which of the sounds being sent to it by the microphone are claps. It does this only by recognizing sounds that fall within a certain frequency range (hand claps are typically within the 2200 to 2800 hertz range) and ignoring everything else.

Every time the filter registers a "clap," it sends a signal to one of two electrical switches -- each of which activate a separate electrical outlets on the exterior of the device, which is where you've plugged in your TV, radio or lamp. The switches are each cued to only turn on if they receive a certain number of signals from the filter. Two signals will set off the first switch, and three signals will set off the second switch.

By clapping, you trigger the microphone to set off the sound filter, which in turn sends a signal to the electrical switches. Clap twice, and two signals are generated, setting off the first outlet. Clap three times, and three signals are generated, setting off the second outlet.

To turn off an outlet, simply repeat the process. When one of the electrical switches is on and it receives the appropriate sequence of signals from the filter, it'll simply switch off.

Keep reading to find out how what a Clapper and a Doberman have in common.

How to Use the Clapper

The Clapper is a notoriously finicky device. Clap too softly or clap too rapidly, and you might find yourself suddenly plunged into darkness when you meant to turn off the TV. It takes a while to get used to it, but after a brief meeting with your new Clapper, you can easily master the art of clapping.

"You don't have to clap very hard," assures the Clapper instruction booklet. The most important part of setting off your Clapper isn't volume, but getting the timing right. Each clap needs to be followed by a half-second-long pause, which allows the device to properly register the separate claps. Pausing after your last clap is particularly important, since the device needs to be sure you're not going to clap again. Clapping twice, therefore, would look something like this: "clap" (half second pause) "clap" (one and a half second pause).

To help you along, the Clapper has a set of three "clap detection" lights. Whenever a clap is heard, a light glows. Claps that are too soft or too fast will be rejected by the Clapper -- and the light will fail to glow.

If, for some reason, your claps keep getting rejected as noise, the Clapper will automatically reduce its sound sensitivity. In those cases, you'll simply need to clap louder. You can also manually adjust the sensitivity, using a dial on the side of the device.

Of course, not everybody can clap, and this can present a problem -- especially given that elderly and disabled people compose a significant segment of the Clapper's target market. In those cases, the Clapper recommends using a "cricket" -- a handheld metal device that, when squeezed, emits loud clicking sounds. In a pinch, the Clapper can also be activated by yelling words in a Clapper-friendly cadence.

The Clapper can even be used as a rudimentary burglar alarm. A switch on the device allows it to be put in either a "HOME" or "AWAY" setting. When set to "HOME," the device functions normally. When toggled to "AWAY," the Clapper becomes ultra sensitive. In "AWAY" mode, both plugs on the Clapper are set to go off at even the slightest noise. The idea is that a burglar will break in, accidentally turn on the lights or TV and be startled out of the house. This system is particularly effective if the switched-on TV happens to be tuned to a Clapper commercial.

So how did the Clapper get its start?

Clapper Origins

An electronic sound filter inside the Clapper is able to recognize your claps.
An electronic sound filter inside the Clapper is able to recognize your claps.
Ralf Nau/Getty Images

Originally dubbed "The Great American Turn-on," the predecessor to the Clapper was first conceived in a Toronto workshop by two Canadian inventors. The pair brought a prototype to advertising mogul Joseph Pedott.

Pedott was a tough customer. Founder of Joseph Enterprises Inc., he was a career marketing and advertising man. Whatever might be said about his grating and repetitive TV commercials, they sold products. "If you do something repetitive, you're doing a little brainwashing," Pedott once said in an interview [source: McMackin].

In the early 1980s, Pedott already had the Chia Pet under his belt, and he was on the lookout for his next big moneymaker. Only one out of every thousand products Pedott saw ever made it into distribution, but the Clapper was special; it was convenient, simple and, above all, patentable. Pedott sealed an agreement with the two inventors, and a Clapper ad campaign and assembly line was soon underway.

The only problem was that the device didn't work. The first Clapper buyers soon found themselves with blown-out television sets. Luckily, Pedott had insurance, but he still lost $60,000 in advertising for the defective product. Meanwhile, the two Canadians tried to make off with funds from Clapper investors. Pedott faced them down in a Canadian courtroom, and the two fathers of the Clapper were driven into bankruptcy.

The public's first look at the Clapper was a spectacular failure. Nevertheless, Pedott refused to give up on the clap-activated switch concept and hired a couple of engineers to redesign the device. Two years later, a functioning Clapper finally hit the market. A jingle was penned, a commercial was shot and American kitsch history was made.

Clappers in the 21st Century

The Clapper Plus comes with a remote control.
The Clapper Plus comes with a remote control.

Clap-on, clap-off technology just doesn't have the same zing it used to. After all, in an era of voice- or motion-activated lights, who can be bothered to clap their hands together anymore?

The Clapper is also incompatible with most modern electronics. Older televisions could be turned on simply by plugging them in to a power source. But most current TVs, radios and computers are switched on by computer-controlled activation. It isn't enough anymore just to plug them in -- which is basically all that the Clapper does. And for the energy-savvy consumer, the Clapper also doesn't work with fluorescent light bulbs.

Still, as much as they can, the makers of the Clapper have tried to keep their product fresh for the 21st century. The Clapper Plus, developed in the late 1990s, ups the ante by coming equipped with a remote control. Users can still activate it with claps, but they can also opt to switch on their lights using handheld buttons. Unlike a standard TV remote, the Clapper's remote control uses radio waves, which allows it to pass through walls or windows -- much like a remote key entry system for a car.

Newer versions of the Clapper have also allowed users to "train" the device. Rather than stick to the old two- and three-clap model, Clapper owners can now set their devices to trigger by individualized clap sequences. Five claps could turn on a table lamp, while two claps, a pause and a third clap could turn on the lights on a Christmas tree.

Even with thought-controlled appliances rumoured to be just over the horizon, the novelty of clap-activation still has a future. A recent iPhone app allows owners to turn their phone into a miniature clap-activated bedside lamp.

The manual light switch has remained generally unchanged since the 19th century, yet it remains a top seller. Whatever inconvenience there is in fumbling through the dark for a switch, the simplicity of the device is what keeps it around. As so it is with the Clapper. It's been called kitschy, cheap and tacky -- but it works, and it's here to stay.

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More Great Links


  • Bud, Barbara. "The Chia Man." As It Happens. May 8, 2009. (December 9, 2009)
  • Gardiner, Virginia. "The purpose of products." Dwell. Vol 4, no. 5. Page 140. April, 2004.
  • Harry, Lou. Stall, Sam. "As seen on TV: 50 amazing products and the commercials that made them famous." Quirk Books. 2002.
  • Joseph Enterprises. "The Clapper Instructions." (December 5, 2009)
  • Key, Stephen. "The success behind Chia Pet, The Clapper & the Ove Glove. What's The Secret?" All Business. May 4, 2009. (December 9, 2009)
  • McMackin, Emily. "The Big Idea." October/November, 2009. (December 6, 2009)
  • United States Patent and Trademark Office. "United States Patent No. 5,493,618." February 20, 1996. (December 9, 2009),493,618.PN.&OS=PN/5,493,618&RS=PN/5,493,618