jonoff t1_ixpfx5n wrote on November 25, 2022 at 6:55 AM Reply to comment by NamityName in Alarm clock lasted over two decades and somehow knows when daylight savings is still by VapeMySemen It's not the sound waves nor speaker that matters here, but what powers the diaphragm of that speaker. The speaker's very small electric coil puts out EM waves at a harmonic frequency the device picks up. Pretty neat trick. Building just a wire loop greatly improves the signal without any audio. http://www.jrcomputing.com.au/Set_Watch/Set_Watch_Manual.html Permalink Parent 47
jonoff t1_ixpfx5n wrote
Reply to comment by NamityName in Alarm clock lasted over two decades and somehow knows when daylight savings is still by VapeMySemen
It's not the sound waves nor speaker that matters here, but what powers the diaphragm of that speaker. The speaker's very small electric coil puts out EM waves at a harmonic frequency the device picks up. Pretty neat trick.
Building just a wire loop greatly improves the signal without any audio. http://www.jrcomputing.com.au/Set_Watch/Set_Watch_Manual.html