The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

The New Hotness

  • 60 kHz Tuning Fork Resonator: Maximum Overdrive

    Datasheets loosely associated with the tuning fork resonators in hand suggest 1 μW maximum drive power, which works out to maybe 100 mVrms = 150 mVpk at about 10 kΩ ESR. If you inadvertently apply 500 mVpk = 375 mVrms, the resulting 14 μW does this:

    Broken 60 kHz Tuning Fork Resonator - overview
    Broken 60 kHz Tuning Fork Resonator – overview

    I was applying a precisely tuned 60 kHz sine wave to the first pass at a crystal filter grafted onto the loop antenna preamp and wasn’t paying attention to the amplitude. For all I know, though, the poor thing died from a power-on transient. I’m pretty sure I didn’t break it during extraction, because it stopped being a resonator while in the circuit.

    The missing tine fell out of the can:

    Broken 60 kHz Tuning Fork Resonator - tine detail
    Broken 60 kHz Tuning Fork Resonator – tine detail

    Laser trim scars form a triangle near the tip, a T a bit further down, a slot just above the nicely etched gap.

    A closer look at the fractured base:

    Broken 60 kHz Tuning Fork Resonator - detail
    Broken 60 kHz Tuning Fork Resonator – detail

    The metalization appears black here and gold in person.

    So, yeah, one down and 49 to go …