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.

Tag: Rants

And kvetching, too

Branson 200 Ultrasonic Cleaner: Wiring Fix

Our ancient Branson 200 Ultrasonic Cleaner began behaving erratically due to water seeping under the rather casual seal from last year’s fix. Although drying the switches let it start up again, it would run for only a few seconds before shutting down again, which suggested a deeper problem than just the switches.

Take a picture of the PCB’s component side:

Branson 200 Ultrasonic Cleaner – PCB component side

And of the solder side:

Branson 200 Ultrasonic Cleaner – PCB solder side

Transform those pictures to be the nice real rectangles shown above, resize to a common pixel format, mirror the solder side, turn it into a layer atop the component side, then tweak its opacity to make both sides visible at once:

Branson 200 Ultrasonic Cleaner – PCB overlay

Some pondering produces a partial schematic of the left half of the board:

Branson 200 Ultrasonic Cleaner – partial schematic

The 1:1 transformer is constantly powered, so the ON button connects the 120 V (!) half-wave rectified output to the +12V supply bus, with the 750 Ω resistor dropping most of the voltage while the switch is pressed.

The hotwired +12V supply forces the relay closed, which (in some as-yet unidentified way) fires up a +12V power source to hold the relay closed, with the 555 timer driving an MC14060 14-bit divider to count down the time until it turns itself off.

Reminder: this design dates back to the days when a pair of chips and a handful of through-hole components cost less than one of those fancy microcontroller thingies.

Plug the cleaner into an isolation transformer and trace the half-wave rectified signal through ON button to find it got all the way to the contact on the end of the orange wire in the connector, but did not reach the pin header on the PCB.

A closer look at the connector revealed a broken contact on the white wire, which I (rather crudely) soldered together while considering my choices:

Branson 200 Ultrasonic Cleaner – soldered contact

While plugging that wire back in place, this happened:

Branson 200 Ultrasonic Cleaner – another broken contact

Neither of those are the (presumably) similarly failed orange wire, but even I can get a clue from three similar failures.

So I replaced the OEM connector with a JST-XHP 2.54 mm connector from an assortment I got for another project, replaced the chunky 22 AWG wires with flexy 26 AWG silicone wires in the same cheerful rainbow colors, and it began working perfectly again.

The buttons needed another water seal, so I tweaked the previous layout to kiss-cut GITD tape and through-cut colorful vinyl sheets:

Branson 200 Ultrasonic Cleaner – power button cutting

Capped with a transparent cover sheet cut from a pack of PDA screen protectors (remember PDAs?):

Branson 200 Ultrasonic Cleaner – power button cover

In truth, the GITD tape is too thick, so I’ll probably repeat this dance later this year.

FWIW, I was totally ready to buy a new ultrasonic cleaner, but all of them have scathing one-star Amazon reviews, to the extent I decided fixing this cleaner would be much easier than fixing a new one that’s been cheapnified to the point of no return. A common complaint seems to be water leaking into their capacitive switches and killing the circuitry stone cold dead: not an improvement over this one.

2026-05-06
Work Sharp Precision Sharpener: Turn Signals

The blade clamp on the Work Sharp Precision Sharpener fits into a socket that can rotate 180°:

Work Sharp Precision Sharpener – Blade Clamp operation

What’s not obvious is that the socket can rotate only 180°, which means you (well, I) must remember which way to turn it based on the presence or absence of the small white mark. I get it wrong somewhat more than half the time while sharpening a small symmetric blade, rather than a knife with a handle, so I added arrows to the socket.

With the white mark upward, turn 180° counterclockwise:

WorkSharp – turn CCW

Then turn it 180° clockwise:

WorkSharp – turn CW

As with the slug filling the uncomfortable button on the back side of the socket, this seems like it should be a standard feature.

2026-05-04
Walkway Over the Hudson: Camera LEDs

Under the plausible assumption the security / surveillance cameras along the Walkway Over the Hudson aren’t the cheapest junk available from a randomly named Amazon seller, this came as a surprise during a recent Walkway At Night stroll:

Walkway Over the Hudson – camera LEDs

The IR LEDs emit just enough red light to be dimly visible to the human eye, but appear much brighter to a silicon detector. I think the long gap at the bottom right is a sensor of some sort, so the array of 18 LEDs has two deaders, one near death, and six more fading away.

The necklace lights on the Mid-Hudson Bridge are once again in good repair:

Mid-Hudson Bridge – 2026-04-24

They were showing fixed white light, rather than a moving color display, but it’s still a nice effect.

2026-04-27
Auto Parking Light LED Bulbs: FAIL

After about eight years and a similar failure last year, this came as no surprise:

White W5W Parking Light – failed chips

It’s a W5W “parking light” in the same fixture as the melty halogen high-beam bulbs (used as daytime running lights at half power), so it gets toasted on those occasions when we drive somewhere.

The adhesive holding the LED strip to the aluminum shell fossilized and came loose:

White W5W Parking Light – failed adhesive

Now that I know what to look for, I’d get LED bulbs with chips soldered directly to the PCB, although it’s not obvious what holds the PCB to the aluminum frame.

I reinstalled the original incandescent bulbs.

2026-04-06
Tax Season: 2026 Edition

Having recently filed our income taxes, this email came as a mild surprise:

IRS Audit email

The From field seemed a bit sketchy, but, hey, maybe the IRS subcontracted their email vendor after having lost much of their staff in the name of efficiency.

The attached PDF document seemed scant:

IRS Audit document

Yeah, I’m definitely clicking that link …

2026-03-20
LED Garage Light: Autopsy

The hidden part of all three LED arrays in the dead garage light looked like this:

LED Garage Light – inadequate heatsink compound

Although the compound was still gooey, there wasn’t nearly enough of it. The few tendrils on the heatsink suggest the LED array had bowed upward, pulled away from the cast aluminum, and eliminated any direct conduction.

A bit of probing showed each LED array had 16 series groups of 4 parallel LEDS, with one group in each array failed open. That group was toward the end away from the inadequate heatsink compound: the LEDs died from heatstroke brought on by neglect.

The Drawer o’ LED Arrays disgorged a bag of surplus LEDs labeled “10 W 9-12 V 750 mA”:

LED Garage Light – epoxy replacement

It’s sitting on a generous blob of steel-filled JB Kwik epoxy that should do a great job of conducting heat. A bag of cheap constant-current supplies is on order.

Amazon has similar “10 W 9-12 V 350-450 mA” arrays.

Try as I might, I can’t get 10 W from those numbers, but I’ve never understood advertising math.

2026-03-10
LED Garage Light: FAIL

A three-wing garage light Came With The House in the basement, where it served to light up the foot of the stairs. One of the 48 LEDs in one of the three LED panels began flickering brightly and, over the course of a few days, that panel went dark. The next time I turned on the basement lights, all three panels were dark.

Removing the screw-in lamp base:

LED Garage Light – overview

A closer look inside:

LED Garage Light – detail

The middle of the PCB is darker than the perimeter, with the darkest area around the black inductor standing up near the green filter cap. A blackened lump on the solder side that may have once been an SMD resistor evidently served as a fuse.

All three panels are in wired parallel, so the failed panel reduced the load on the supply, thus increasing the voltage on the remaining two panels enough to kill them off, too.

Worth noting: the black wire goes to the positive side of the LED panel. You can just see the + mark near the two connectors on the left side.

I wired each panel to a lashed-up bridge rectifier with a widowmaker extension cord from a variable transformer controlling the voltage, but none of them responded to the 150 VDC peaks: they’ve suffered Real Death.

The electronics landed in the recycling box and the three heatsinks are now in the Big Box o’ Heatsinkery, where they will surely come in handy for something.

The surprisingly readable 09/21 date code on the case says it’s just over four years old. Similar garage lights now run around ten bucks each and I wouldn’t expect them to last more than a couple of years.

2026-03-05