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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