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Tube Time

4 Jan, 5 tweets, 1 min read

ever wonder how an old-school Christmas tree "flasher bulb" works? check out this microscope video.

yes, it's one of those bulbs with the red tip. you plug it into a string of bulbs and it flashes the whole string because they're connected in series.

the metal contact that moves ever so slightly is actually a bimetallic strip -- a sandwich of two different types of metals.

when the filament heats up, the metals expand at different rates which causes the contact to curve away from one of the terminals, which breaks the circuit. the filament turns off and won't turn back on until the temperature falls again.

it's an electromechanical relaxation oscillator!

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More from @TubeTimeUS

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3 Jan

recently i found a surprisingly interesting IC socket. it looks like an ordinary socket BUT there's a patent pending notice on it, and...

...it's also a lot thicker than a regular IC socket. like twice as thick!

i pulled the lid off of it, and the bottom half appears to have some circuitry inside it. you can see some traces on a circuit board through the gap in the molded plastic.

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3 Jan

the resistor in the foreground has only one stripe. 🤔

this is because it is a zero ohm resistor. yes, zero. but wait--you say--isn't that just a wire?

so let's cut it in half and see. does it look like a wire to you?

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1 Jan

so i needed a tool for straightening IC pins because they often come with their leads splayed out and won't fit in a socket or a PC board. this is the version you can find at a variety of online stores. but--i need one *now*

ok, i have a 3d printer, so i'll go on Thingiverse and find one. here's one that looks good.

except--i don't have the right springs. i don't have the right fasteners. it only does 0.3" narrow DIP ICs. it's basically a mess.

Read 12 tweets

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31 Dec 20

Tube Time: a 2020 retrospective 🧵

https://twitter.com/TubeTimeUS/status/1215071399829622784

i started off the year by releasing a new Micro Channel sound card, the Plaid Bib CPLD edition. little did i know that this would not be the only sound card i would release this year.