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Posts Tagged Rants

Low Budget Bench Power Supply

The idea behind this gadget surfaced while I was looking for something else and, although the front panel makes my skin crawl, it’s just an adjustable DC power supply:

Tattoo power supply - original front panel

Tattoo power supply – original front panel

This is apparently the cheapnified version of the item appearing in the eBay listing:

Tattoo Power Supply - eBay listing photo

Tattoo Power Supply – eBay listing photo

Let’s say it has the potential to be a DC power supply, although we might quibble about the “Precision” part.

As delivered, it’s a deathtrap. Of course, it’s not UL listed and I didn’t expect it to be.

How many lethal problems do you see?

Tattoo power supply - original AC wiring

Tattoo power supply – original AC wiring

For starters, it has a three-wire AC line cord with the green-and-yellow conductor chopped off flush with the outer insulation inside the heatshrink tubing just behind the transformer:

Tattoo power supply - ungrounded AC line

Tattoo power supply – ungrounded AC line

The blue wire is AC neutral, but it really shouldn’t be connected to the finger-reachable outer fuse terminal.

The brown wire is AC line, which goes directly to one power switch terminal. In the event of a hot wiring fault, an unfused conductor touching the case will test the GFI you should have on your bench wiring.

The AC line cord uses some mysterious copper-colored metallic substance that’s about as stiff as music wire:

Tattoo power supply - stiff AC wire

Tattoo power supply – stiff AC wire

The strands cannot be twisted together like ordinary copper wire, although they can be soldered. They may be copper-plated aluminum, because a magnet ignores them.

After soldering the strands together, they snap when bent:

Tattoo power supply - soldered broken AC wire

Tattoo power supply – soldered broken AC wire

Generous strain relief is not just a good idea, it’s mandatory.

After some Quality Shop Time, the ground wire now connects to the case through the transformer’s rear mounting screw, the neutral AC wire connects to the transformer, the hot AC wire goes to the tip of the line fuse, and the fuse cap terminal goes to the switch:

Tattoo power supply - AC line rewiring

Tattoo power supply – AC line rewiring

I relocated the white LED to the middle of the meter, where it looks a bit less weird:

Tattoo power supply - revised front panel

Tattoo power supply – revised front panel

I have no idea what “Porket indicate” might mean. Perhaps “Precision indicator”?

The right 1/4 inch jack, labeled “Foot”, normally goes to a foot switch you don’t need for a bench power supply, so I converted a length of drill rod into a dummy plug to short the jack contacts:

Tattoo power supply - dummy switch plug

Tattoo power supply – dummy switch plug

The tip comes from a bit of lathe and file work and the white cap comes from a bag of wire shelf hardware.

A genuine hologram sticker (!) on the back panel proclaims “1.5 – 15 VDC 2 A”, which seemed optimistic. Some fiddling with power resistors suggests tattoo liners (I learned a new word!) don’t draw much current:

  • 4 V @ 1 A
  • 8 V @ 800 mA
  • 10 V @ 600 mA

It can reach a bit over 18 V (pegging the meter) at lower current, so it’s Good Enough for small projects with un-fussy power requirements.

Caveat emptor, indeed.

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Wandering Washroom Water

You’d think architects would know better:

Fancy washroom counter

Fancy washroom counter

The washroom has in-the-wall towel + trash stations at each end of the counter, but they’re obviously inadequate for the purpose. Fortunately, the counters slope away from the attractive stacks of paper towels.

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Hooker Avenue at Raymond: Left Turn on Red

T=0: You can’t tell, but the signals for Hooker Avenue have been yellow for several seconds and are about to turn red:

Raymond - Left on Red - 2017-10-11 - 1

Raymond – Left on Red – 2017-10-11 – 1

T+3: The opposing signals have been red for a while, but nobody much cares about that:

Raymond - Left on Red - 2017-10-11 - 2

Raymond – Left on Red – 2017-10-11 – 2

T+11: Right-turning traffic (with a green arrow) blocks his path, so he just drops to a dead stop in the middle of the intersection:

Raymond - Left on Red - 2017-10-11 - 3

Raymond – Left on Red – 2017-10-11 – 3

T+14: Finally! All clear for a left on red:

Raymond - Left on Red - 2017-10-11 - 4

Raymond – Left on Red – 2017-10-11 – 4

When a cyclist delays a driver for two, maybe three, seconds, even while riding legally, outrage occurs.

And, yeah, I’ve made mistakes, too. Happens to everybody. Cyclists seem to arouse disproportionate outrage, so I try very hard to ride within the rules and the lines.

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Burnett Blvd at Rt 55: Passing on the Right, Redux

As usual, we’re at the Rt 55 end of Burnett Blvd, returning home from a grocery trip; I’m hauling two full bags of chow in the trailer. The white car pulling up immediately to our left will make a left turn from the left lane:

Burnett at Rt 55 - Right Pass - 2017-09-19 - 01

Burnett at Rt 55 – Right Pass – 2017-09-19 – 01

The more distant white car, turning left out of Overocker, is eases past us in the right lane to make a right turn:

Burnett at Rt 55 - Right Pass - 2017-09-19 - 02

Burnett at Rt 55 – Right Pass – 2017-09-19 – 02

We’re on the left side of the right lane, rather than the right, to avoid right hook collisions with drivers who flat-out do not stop before turning. Been there, had that happen, we know better.

The car approaching in the right lane will attempt to pass us on the right:

Burnett at Rt 55 - Right Pass - 2017-09-19 - 03

Burnett at Rt 55 – Right Pass – 2017-09-19 – 03

That’s happened before, too, so I’m watching this happen in  my mirror. My line will pass to the right of the inconveniently placed manhole cover in the intersection:

Burnett at Rt 55 - Right Pass - 2017-09-19 - 04

Burnett at Rt 55 – Right Pass – 2017-09-19 – 04

Mary’s nearing the right side of the lane, I’m in the middle, and the driver jams to a stop rather than run up over the sidewalk:

Burnett at Rt 55 - Right Pass - 2017-09-19 - 05

Burnett at Rt 55 – Right Pass – 2017-09-19 – 05

The passenger window is rolling down, which is always a Bad Sign:

Burnett at Rt 55 - Right Pass - 2017-09-19 - 06

Burnett at Rt 55 – Right Pass – 2017-09-19 – 06

It’s all the way down and I know what’s about to happen:

Burnett at Rt 55 - Right Pass - 2017-09-19 - 07

Burnett at Rt 55 – Right Pass – 2017-09-19 – 07

So I preempt the discussion by pointing out she was passing in an intersection and the license plate on the silver Chevy say FEX-4194:

Burnett at Rt 55 - Right Pass - 2017-09-19 - 08

Burnett at Rt 55 – Right Pass – 2017-09-19 – 08

She passes Mary and stops directly ahead of us in the middle of the right-hand lane. We jam to a stop behind her. The black car approaching us swerves into the middle lane:

Burnett at Rt 55 - Right Pass - 2017-09-19 - 09

Burnett at Rt 55 – Right Pass – 2017-09-19 – 09

She pulls around the corner onto Manchester and stops in the intersection. I stop well behind her to remain visible from Rt 55, which turns out to be a Good Idea:

Burnett at Rt 55 - Right Pass - 2017-09-19 - 10

Burnett at Rt 55 – Right Pass – 2017-09-19 – 10

Mary eases beside the drivers window, which rolls down. The driver says she’s going to call the police, “because we pulled directly in front of her”. Mary points out we have video of the entire encounter. The window rolls up and the driver pulls away.

Overocker, Burnett, and a short sprint on Rt 55 to Manchester is the only route from the grocery store to Rt 376 and home, so it’s not like we’re looking for trouble.

No helmet camera video, alas, because I tried those piece-of-crap Wasabi batteries in the Sony HDR-AS30V and the second one was flat-out dead. The first one, in the camera when I left home, showed empty after the half-hour ride to the grocery store, so they really are junk; “Premium Japanese cells” my foot.

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Wasabi NP-BX1 Batteries: Consistent FAIL

The replacement NP-BX1 batteries arrived and, as I expected, perform just as badly as the previous pair:

Sony NP-BX1 - Wasabi GHIJK - 2017-09-01 - annotated

Sony NP-BX1 – Wasabi GHIJK – 2017-09-01 – annotated

The note I sent to Wasabi’s tech support summarizes the details:

The second pair of NP-BX1 batteries are just as bad as the first two. In fact, all four perform worse than the nearly two-year-old Wasabi batteries I’ve been using.

The graph shows the test results from my CBA III analyzer. All batteries were all charged in a Wasabi wall charger.

The top solid red curve shows the as-delivered performance in late 2015 for the battery I labeled “G”, tested at 500 mA. It delivered only 1 Ah, not the claimed 1.6 Ah, even at that relatively low current, but has delivered over one hour of service in the camera.

The top dotted-blue curve shows the as-delivered performance for the NEW battery I labeled “J”, also tested at 500 mA. It delivers only 0.88 Ah, 55% of the claimed 1.6 Ah, at a much lower voltage while discharging.

After two years, OLD battery “G” has more capacity and a higher voltage than the NEW battery “J”!

The lower curves shows the results for the four most recent batteries I labeled H I J K, all tested at 1 A to better match the camera’s actual current; the dotted traces mark the second test of each battery.

The orange traces show battery K has about 0.77 Ah of capacity, less than half of the claimed 1.6 Ah and much worse than the others.

I also re-tested battery old battery G at 1 A, as shown by the dotted red curve labeled “G:2017-09”. It outperforms ALL of the new batteries!

Batteries H and I have date codes BQF22, which I interpret as 2017-06-22: fairly recent stock.

Batteries J and K have date codes BPL28: 2016-12-28. They’ve been sitting around for a while, which may account for the poor performance of battery K.

These Wasabi batteries cost roughly twice (*) as much as they did in late 2015, have /much/ lower capacity, and, to judge from the date codes, they’ve been consistently poor since late last year.

What is going on?

It’s worth noting that Wasabi NP-BX1 batteries are currently $16 for the pair on Amazon and were $9 in late 2015. Allegedly genuine Sony NP-BX1 batteries run $50 MSRP and a suspiciously consistent $37.99 from all the usual big-box sources, including Amazon, where they’re out-of-stock for the next few months. Combining the number of counterfeits in the supply chain with Amazon’s commingled SKU stock bins, I have my doubts about what I’d get by increasing my battery spend by a factor of five.

I think it’s about time to conjure an external 18650 holder / helmet mount for that camera and be done with it.

[(*) Edit: I screwed up the unit of measure: the old invoice had two single batteries. The new order was one pair, so I now pay slightly less for much worse performance. A refund is wending its way through the system.]

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Sharp EL-531W vs. EL-531X Calculators

(Typo in the permalink: should be W vs. X. Fixing it will break all the auto-linkies. Hate it when that happens.)

When our lass first began using calculators, I put a pair of Sharp EL-531W calculators in harm’s way around the shop, where they still reside. The new EL-531X seems to have an identical key layout and internal logic (*), as well as the same under-ten-buck price, but I don’t like it nearly as much:

Sharp EL-531W EL-531X calculators

Sharp EL-531W EL-531X calculators

It’s maybe 10 mm wider and doesn’t fit readily in my hand. I’m sure the rounded-rectangle stylin’ mimics a phone, but the cheapnified keys look ugly (particularly the ones around the arrow keys at the top) and don’t feel nearly as good.

The new one fills a gap next to the lathe, where it should collect plenty of swarf.

(*) Including engineering notation with multiple-of-three exponents, which I regard as vital.

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Wasabi NP-BX1 Batteries: FAIL

I just got a new pair of Wasabi Power NP-BX1 batteries for the HDR-AS30V helmet camera, charged them up, and ran them through the CBA:

Sony NP-BX1 - Wasabi FGHI - 2017-08-08

Sony NP-BX1 – Wasabi FGHI – 2017-08-08

Huh.

The new ones (H and I) cost near twice as much as the 2-1/2 year old previous pair (F and G), while delivering less energy at a lower terminal voltage. Tested ’em twice to be sure and the curves overlay just about perfectly, so it’s not a fluke.

The rep assures me the replacement cells will deliver their promised capacity. We shall see.

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