Mushrooms

We spotted a plump mushroom cluster nestled at the base of a neighbor’s tree:

Mushrooms at tree - A
Mushrooms at tree – A

Eight days later they’d started curling:

Mushrooms at tree - B
Mushrooms at tree – B

Mushrooms growing on tree roots generally mean the tree is in trouble and, indeed, it’s a battered Black Locust.

Lyme Disease

For reasons that made sense at the time, two weeks ago I ventured outside the house. A few days later, this appeared:

Lyme Disease - arm rash
Lyme Disease – arm rash

The pallid skin over on the left comes from a bike glove. The central bump is one of those annoying sebaceous hyperplasias appearing after a Certain Age and not relevant here.

Having been around this particular block a few times, Mary recognized the diffuse red rash, sleeping 30 of 36 consecutive hours, and a day-long 103 °F fever as Lyme disease. I’m currently taking 100 mg of doxycycline twice a day and (after a week) feeling better, while sleeping a lot more than usual at random intervals during the day.

We’re both highly aware of Lyme disease: Mary routinely dresses in a complete overlayer of permethrin-sprayed clothing and I generally strip-and-shower immediately after any yard work in similarly sprayed, albeit less enclosing, attire. In this case, we think a tiny Deer Tick nymph affixed itself to the outboard side of my wrist, where I could neither see nor feel it, and (because I didn’t take a shower after being outside for only a few minutes) remained attached long enough to infect me.

Caught and treated early, Lyme disease generally does not progress into “post-treatment Lyme disease”, an ailment rife with what can charitably be described as serious woo, despite some evidence of actual disease.

Some of Mary’s Master Gardener cronies have endured co-infections of Babesia microti and we’ll be watching for those symptoms after doxycycline tamps down the obvious problem.

I’ll be puttering very carefully around heavy machinery and posting irregularly for a few weeks …

Memo to Self: the Basement Shop has a lot to recommend it!

Small Spider vs. Marmorated Stink Bug

Spiders know how to handle much larger prey:

Spider draining Marmorated Stinkbug
Spider draining Marmorated Stinkbug

Apparently the stink bug’s armor doesn’t count for much when the spider has the luxury of attacking through a weak spot in the underbelly after the critter stops struggling.

Stink bugs cause considerable damage to crops (notably apples) in the Hudson Valley, but they haven’t been the existential catastrophe we all expected when they first arrived.

Hooray for spiders!

UPS SLA Battery Status

The UPS coddling the M2 printer began complaining about a bad battery, so I ran (nearly) all the UPS batteries through the tester:

UPS SLA 2021-10-10

The two blue flubs in the lower left come from the failed battery, with the dotted trace after charging to 13.7 V and letting the current drop to 20 mA.

The red and green traces come from two other UPS batteries installed in 2016, with the dotted traces after charging similarly. The orange-ish trace is from the battery in a Cyberpower UPS bought in 2016, so it looks like all batteries of that vintage fade equally.

Except for another pair of batteries in another UPS that had discharged stone cold dead; it may have been shut down and unplugged during a power outage and they never quite recovered.

After five years, it’s time to refresh the fleet …

BatMax NP-BX1 Status

The Sony HDR-AX30V helmet camera puts far more demands on its battery than the Planet Bike Superflash:

Batmax NP-BX1 - 2021-09 vs 2020-03
Batmax NP-BX1 – 2021-09 vs 2020-03

The four traces on the right show the BatMax NP-BX1 lithium batteries (cells, really) originally stored about 3 W·h when they arrived in March 2020. The four solid traces to their left show the capacity dropped to a little over 2 W·h after two riding seasons. Batteries B and C started out above average and are now below, for whatever that means.

The red dotted trace shows the effect of not using the NP-BX1 test holder for that length of time; those homebrew contact pins apparently needed some exercise.

Panasonic Eneloop AAA NiMH: Four Years of Blinking

Having replaced the Planet Bike Superflash on Mary’s Tour Easy with a 1 W red LED, testing the eight Panasonic Eneloop AAA cells that have been powering it (and the one on my bike) for the last four years seemed useful:

Panasonic Eneloop AAA - 2021-09 vs 2017-04
Panasonic Eneloop AAA – 2021-09 vs 2017-04

The sheaf of curves over on the right came from the first full charge, with the untidy collection below them show the current state after a full charge. This is at an unreasonably high 500 mA discharge.

The overall capacity has dropped by 10%, which isn’t all that bad, but the 10% voltage reduction toward the end of the curves is a Bad Thing for an LED flasher intended to run from 1.5 V alkaline cells. In practice, I recharge the batteries once a week while they are still going strong, but the difference between alkalines and NiMH cells is obvious even at full charge.

Now I can run four pairs through the aging Superflash on my bike …

Tour Easy Rear Running Light: Current Waveforms

There’s just enough slack in the LED wiring to clip a Tek current probe in there:

Tour Easy Rear Running Light - regulator wiring
Tour Easy Rear Running Light – regulator wiring

Which reveals the LED current waveform:

Red LED - LED current - 100 mA-div
Red LED – LED current – 100 mA-div

The LED is on continuously, except for the two 75 ms Morse code dits in the upper trace.

The lower trace shows the current ramping up at the end of the first dit, from zero to 400 mA in 1.5 ms.

Clamping the probe around the 6.3 V power supply lead:

Red LED - power supply - 100 mA-div
Red LED – power supply – 100 mA-div

The supply current includes maybe 20 mA for the Arduino running the Morse code program and the current ramps up from there to about 250 mA when the LED is on.

The LED drops 2.6 V at 400 mA, so it dissipates a smidge over 1 W. The 2.0 Ω current sense resistor (3.3 Ω in parallel with 5.1 Ω) dissipates 800 mV × 400 mA = 320 mW.

The dissipation from the Bafang headlight output, including the Arduino, is 1.6 W.

The running light ticks along at the hot side of comfortably warm on the Electronics Workbench and runs barely warm in free air out on the bike, so I’ll define it to be Good Enough™.