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Atomic Clock Movement versus the Auto-Set Movement


Auto-Set High-Torque battery clock movements have now changed the way we adjust clocks for Daylight Saving Time(DST). For the past decade or so a radio controlled movement, or Atomic clock movements, were the only way to do this. The battery clock movement would receive a radio signal, and either stop or fast forward an hour to adjust for Daylight Saving Time.

In theory this was a great idea, because the time broadcast on radio station WWVB is based on the Caesium -131 Atomic Clocks in Fort Collins, Colorado. It’s very accurate and it’s broadcast on a low frequency AM radio wave. Unfortunately, there are a variety of AM broadcast issues which can potentially cause interference with the reception of the atomic clock signal being broadcast.

In practice, AM (amplitude modulation) radio waves can achieve long distances. There are potential problems include interference from, power tools, appliances light dimmer switches and especially solar geomagnetic storms, which are quite common.  At their strongest, these storms cause the atmosphere to “light up” in northern and southern regions of earth, producing the northern (and southern) lights.

An Auto-Set clock movement does not have the potential problems that an atomic clock movement does. It’s more reliable because it does not depend on receiving a radio signal. Now Auto-Set movements completely eliminate the need to receive a radio signal at all, and still adjust for Daylight Savings Time (DST) twice a year. All of the potential problems with a so called Atomic Clock Movement are gone.

We at are proud to introduce our High Torque Auto-Set movements. We have both a US and a World version. They are unique because they will power clock hands up to nearly 18” long if desired. They take advantage of a new technology which utilizes a digitally based computer chip, which serves as a pre-programmed digital clock movement.

The primary power source is the AA battery, but the time is sequenced by a tiny quartz chip which oscillates at a very regular frequency. It requires very low voltage. This common, long lasting LR44 battery will keep the chip operating when the standard AA battery is removed and replaced.

The High Torque Auto-Set Movements are capable of operating clock hands nearly 18″ long. A common use, is for large wall clocks that may be installed high up on a wall. Imagine not having to get out a ladder to change the time twice a year!

At the beginning of the fall season, the internal clock movement will signal the Auto-Set movement to stop operating for exactly one hour (fall back). In the Spring, it will make the movement run at a higher speed to advance the time by one hour (Spring forward). This process takes about 6 minutes. You don’t have to do a thing, just sit back and watch, if you are still up in the middle of the night.

We have Auto-Set movements for operation in all four of the time zones of the continental United States as well as a “world” model  that can operate in all 26 time zones around the world.  Amazing technology. Both of these movements have a 5/16″ threaded hand shaft length, which will work well with a clock dial thickness up to ¼”.

The clock hands use the common American “I” shaft configuration, which makes over 50 hand styles and lengths available for these movements. Anywhere from an inch and a half up to nearly 18 inches.

You can use these movements to repair an existing wall or table clock, or you can make your own design – large or small . You can even use one of our wall mounting cups to mount the US version to the wall, to make a very large wall clock. Use photos or our stick-on numbers to tell the time. People have also used metal house numbers from a local hardware store for large clock faces. Get creative.