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Archive for October, 2016

Inside Another 9 V Battery

A long time ago, I discovered some quasi-AAAA cells inside 9 V batteries:

Inside a batteries.com 9V battery

Inside a batteries.com 9V battery

It occurred to me that I should dismantle a defunct Rayovac Maximum 9 V alkaline battery from the most recent batch (*) to see what it looked like:

Rayovac Maximum 9V battery - interior

Rayovac Maximum 9V battery – interior

Surprise!

A closer look at those pancake cells:

Rayovac Maximum 9V battery - detail

Rayovac Maximum 9V battery – detail

They look like separate cells bonded into a stack, although there’s no easy way to probe the inter-cell contacts; the leftmost cell probably died first.

(*) Which has apparently outlived the Rayovac Maximum brand, as they don’t appear on the Rayovac site.

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Running Lights

New Cadillacs have thin white LED running lights along the front edges, with angular chromed trim below:

Cadillac running lights

Cadillac running lights

Their SUVs have matching vertical-stripe taillight / markers; it’s obviously a stylin’ thing. If it weren’t for the power, I’d run LED strips along the edge of the fairing & seat frame on our ‘bents.

Probably due to having read Glory Road at an impressionable age, those lights always remind me of Heidelberg dueling scars:

Adolf Hoffmann-Heyden -- Dueling scar

Adolf Hoffmann-Heyden — Dueling scar

Cannot be unseen…

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Good Signage Seems Difficult

As expected, the mis-assembled cart corrals in the Walmart parking lot remain that way. One corral has an additional feature that’s surely been there since Day 0:

Walmart cart corral - backwards and upside down

Walmart cart corral – backwards and upside down

On the upside, that’s a high-reliability, high-availability trash can.

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Vacuum Tube LEDs: 6H6GT Dual Diode

Having accumulated a set of octal tube base clamps, it’s now a matter of selecting the proper clamp for each tube:

Octal tube base V-block clamps

Octal tube base V-block clamps

The process of shell-drilling the tube base, drilling the hard drive platter, printing a tube socket and case, wiring up the Arduino and base LED, then assembling the whole thing requires a bit of manual labor, assisted by some moderately exotic shop machinery.

The getter flash atop this small 6H6GT dual diode tube rules out a cap and there’s not enough space for a side light:

6H6GT - on platter

6H6GT – on platter

Fortunately, the base LED completely lights the internal glass:

6H6GT - purple phase

6H6GT – purple phase

The slowly changing color would make a fine night light:

6H6GT - cyan phase

6H6GT – cyan phase

It must be Art!

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Cast Iron Pan Electrolysis: Anode Fragment

Sacrificing a scrap EMI shield from a junked PC as the electrolysis anode, I grabbed a tab with the battery charger clamp:

Cast iron pan electrolysis - bucket

Cast iron pan electrolysis – bucket

Turns out it didn’t survive the encounter:

Cast iron pan electrolysis - anode front

Cast iron pan electrolysis – anode front

That white blob extends around to the other side:

Cast iron pan electrolysis - anode rear

Cast iron pan electrolysis – anode rear

Yeah, it got hot enough to melt a blob from the 6 gallon plastic bucket before burning through.

I tossed that into the garage so I wouldn’t forget it aaaand here we are …

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Hand Sprayer Hose Kink Prevention

Mary’s new half-gallon sprayer arrived with a kink in the hose just below the handle, which is about what you’d expect from a non-reinforced plastic tube jammed into the smallest possible box containing both the sprayer and its wand. Fortunately, the Box o’ Springs had one that just fit the hose and jammed firmly into the handle:

Sprayer hose with kink-resisting spring

Sprayer hose with kink-resisting spring

The kink slowly worked its way out after being surrounded by the spring and shouldn’t come back.

That was easy…

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Vacuum Tube LEDs: 5U4GB Vacuum Rectifier with Sidelight

A larger version of the V-block clamp accommodates the 35 mm = 1-3/8 inch octal base of a 5U4GB Full-Wave Vacuum Rectifier tube:

5U4GB - spigot milling

5U4GB – spigot milling

The evacuation tip nearly touched the inside end of the base spigot!

I had to cut the shaft and half the body off the shell drill in order to fit it into the space above the tube base and below the chuck:

5U4GB - base shell drilling

5U4GB – base shell drilling

A slightly larger shell drill would still fit within the pin circle, but the maximum possible hole diameter in the base really isn’t all that much larger:

5U4GB - base opening

5U4GB – base opening

The getter flash covers the entire top of this tube, so I conjured a side light for a rectangular knockoff Neopixel:

Vacuum Tube Lights - side light - solid model

Vacuum Tube Lights – side light – solid model

There’s no orientation that doesn’t require support:

Vacuum Tube Lights - side light support - Slic3r preview

Vacuum Tube Lights – side light support – Slic3r preview

A little prying with a small screwdriver and some pulling with a needlenose pliers extracted those blobs. All the visible surfaces remained undamaged and I cleaned up the curved side with a big rat-tail file.

I wired the Arduino and Neopixels, masked a spot on the side of the tube (to improve both alignment and provide protection from slobbered epoxy), applied epoxy, and taped it in place until it cured:

5U4GB - sidelight epoxy curing

5U4GB – sidelight epoxy curing

The end result looks great:

5U4GB Full-wave vacuum rectifier - side and base illumination

5U4GB Full-wave vacuum rectifier – side and base illumination

 

It currently sends Morse code through the base LED, but it’s much too stately for that.

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