Maker, Warren Telechron, Inc., Ashland, Massachusetts, USA. Model Type E, c. early 1930's, serial no. 17. Originally set up at the Tennessee Valley Authority (TVA), to control the 60 cycle frequency of the generators across the power grid. One second compensated pendulum (Invar) with separate magnetic control trimmer. Designed to be operated under partial vacuum. 59"h, base 20" diameter, glass tube 49.5" x 10.5" diameter.
Parts of the movement as well as the metal used in the enclosure are made from aluminum. This example contains automatic time error correction through a series of servo motors, switches, levers and cams that detect the rate of the pendulum and adjust themselves to it. Telechron's first model, the Type A required an operator to observe the difference and initiate changes manually. It appears that the Type E had a very limited production and little is known about it. Only one other non-working example, s/n 11, is known at this time.
Click on the picture to go to a page for more detail.
Why did this clock never see regular production? One can only speculate but I submit a few reasons based on my experience with this artifact and the context of the times when it was launched. First, this was introduced during the Great Depression, so any new product launch would be severely crippled, even by a firm and inventor as renown as Henry Warren and his Telechron company. Second, Warren's design, while incredibly ingenious suffered from complexity and fast moving parts. Whereas the competition relied on precision machining and perfect execution (Reifler, Shortt). Warren's movement was, an 'erector set' quality in comparison. He made up for this with his ingenious frequency feedback control system, but nonetheless, it required a great number of rapidly moving components. A master clock must be able to run for long periods of time undisturbed to achieve a good rate of accuracy and Warrens design precluded this. Perhaps this was not an issue in the narrow scope of power house frequency control, but I doubt it. The fact that the clock was meant to be sealed in a partial vacuum indicates that had to be reliable for long periods of time which, in my opinion, was impossible using this design.
The first video shows the front view. The three incandescent lamps are not an original feature but was put in to demonstrate the output of the commutator. The combination of electrical output would be used to control a device to regulate the generators in a power plant or other device. Very similar to the function of a governor. In the second video one can see the epicyclical wheel rotation and in the third it's rotation in step with that of the commutator. The epicyclical wheel is tied into the regulation of the clock's dial while the commutator sends the same motions as electrical commands for remote control. The fourth and fifth videos show the frequency sampler driven by a rotating cam and delivered via a set of stepped contacts to the bi-directional motor connected to both the epicyclical wheel and commutator. Last two show an overall view of the clock before and after restoration. It should be noted that under normal operating conditions the bi-directional motor and thus the epicyclical wheel as well as the commutator would move quite seldom. After all adjustments are made and the system has time to settle, the line frequency and the pendulum would generally be in agreement. I have purposefully upset this equilibrium for purposes of this display.
Telechron_E_vid1.MPG Telechron_E_vid2.MPG Telechron_E_vid5.MPG Telechron_E_vid3.MPG Telechron_E_vid4.MPG Telechron_E_vid6.MPG Telechron_E_vid7.MPG