Continuous Sweep Wall Clock

50 ms/div, 0.5 seconds full screen

Plot of output from magnetic sensor placed near the back of the clock. It's not as consistent as I would expect. Part of this may be the location of the sensor. Moving the sensor a few cm or even a few mm here and there changes the look of the signal. This trace was made with the cleanest possible arrangement. But the general idea comes through: there are many pulses per second, not the usual one pulse per second found on almost all other quartz clocks.

25 ms/div, 0.25 seconds full screen

Zoom in by 2x. A consistent pattern is seen every 125 ms. It looks like a cycle of 2 medium peaks, 1 wide peak, 1 narrow peak, 1 wide peak. That would be 5 peaks in 125 ms, which is on average 1 peak per 25 ms, which is 40 pulses per second.

10 ms/div, 0.10 seconds full screen

Looking at the mid-point of the pulses, it looks like the pulses are about 5 ms or 10 ms or 20 ms wide. Again, this may be related to exactly there the sensor is placed and also the gain and bandwidth of the sensor and its signal conditioning. Still, it's an interesting view.

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