A Crummy Commercial

Interesting article in IEEE Spectrum : https://spectrum.ieee.org/familiar-machines-and-magic It's not a pet or a friend, it's a robotic familiar ?  The first thing I thought of was Jiminy Cricket - but this robotic familiar is trying to help humans become better rather than trying to turn a puppet into a real boy :) Here's the company site:  https://www.familiarmachines.com/ I dunno, seems like a mechanical pet or artificial friend to me.  And with real pets or friends you feel bad when they die.  This thing will eventually die.  I've heard that the Sony Aibo, the robotic dog, was beloved by it's owners and now that Sony doesn't support it anymore, they feel bereft when nothing more can be done.   They were called Artificial Friend (AF) in this book:  https://en.wikipedia.org/wiki/Klara_and_the_Sun I shudder to think what kinds of short videos will be made by teens for social media - the poor familiar ! Best Regards, Chuck, WB9KZY http://wb9kzy.co...

I took a second look at measuring the leakage current of the Renogy solar panel - that first reading of ZERO current kinda bugged me. https://wb9kzy.blogspot.com/2026/05/the-renogy-solar-panel-dischargeleakage.html   I used the newer Triplett DVM just in case there was some kind of problem with the Metex used before.   At 12.84 volts I again measured zero current in any of the three ranges. So I was thinking about that and this is my surmise: there are lower voltage Schottky diodes like the 1n5818, 1 A diode I used on the other solar panel.  The low voltage diodes have somewhat high leakage currents.  Then there are higher voltage Schottky diodes for use in switching supplies and the like.  They have higher forward voltages but smaller leakage currents.  Here is part of a Nexperia Schottky diode data sheet: I will have to pay the tariff tax and get some of these How does this fit in with the Renogy solar panel ?  The Renogy has 72 solar cells which I a...

The reason for action was a spam email from Starlink.  I had looked at Starlink some years ago but never went ahead.  But the spam said that through the end of April they had a special offer to try Starlink for $35 per month for four months.  It rises to $50 per month after that.  So I signed up on April 23rd.  It took a while but the antenna/transceiver, power supply and router with cabling arrived at the ferry dock on Saturday May 2. It was a long bicycle ride to the ferry and back so I just let the surprisingly heavy box sit until Sunday May 3.   Actually opening the box was quite a chore.  Starlink uses boxes like Mouser - no tape is employed, they must hot glue the tabs of the box lid.  Then you are supposed to rip off the pre-perf strips but the strips break - it would have been quicker to use a knife or scissors ! Anyway, once open there is a big pictorial diagram of how things go together. ground station on the left, diagram with the power...

Renogy made this 10 watt solar panel bought this year: https://wb9kzy.blogspot.com/2026/03/solar.html so as was mentioned yesterday: https://wb9kzy.blogspot.com/2026/05/32-diodes.html lets look at the leakage current involved.  As with the UPG solar panel from yesterday, I waited until dark, then covered the panel and measured the battery voltage and the battery to solar panel leakage (discharge) current: 12.84 volts but ZERO current, there must be some kind of low leakage circuit inside the Renogy panel ? I didn't bother to count the lines (diodes) on the Renogy, counting gets tedious after a while and also this panel seems to be different.  But the specs are almost identical: The problem with having the nice cables and clips is that I hate to cut them to add a diode but since there is no leakage, no cutting required, nice ! Best Regards, Chuck, WB9KZY http://wb9kzy.com/ham.htm

I was thinking about the series blocking diode addition to my recent solar panel purchase: https://wb9kzy.blogspot.com/2026/04/make-or-buy.html Certainly there is a drop across the diode when the panel is charging, less than 250 mV with low current.  But is it really needed ? Looking at the solar panel itself again there are 6 wafers, each wafer has 6 groupings of photodiodes with 6-5-5-5-6 diodes each or 32 total diodes in series. count the wider horizontal dark lines to determine the number of solar cells   Per Wikipedia the output voltage of a silicon solar cell (diode) is .5 to .6 volts.  Multiply 32 diodes times .56 volts gets to roughly 18 volts which is about the rated voltage: 21.6 volts divided by 32 is .675 volts so this sounds reasonable for a no-load situation. Now since the panel is charging a lead acid AGM / gel-cell battery the highest voltage that the battery could apply to those 32 diodes is roughly 13 volts: source:  https://voltagebasics.com/lead-a...

looking at this EDN Design Idea :  https://www.edn.com/custom-diy-dmm-smd-fixture-for-low-z-measurements The thing that caught my eye was the clamp - the article calls them: Lever arm-toggling ?  Really ?  In the olden days of the 1970s/80s/90s we called them: De-Sta-Co clamps because that's what was stamped into the clamp  :)   I imagine that there are many generic versions now.   In our receiving inspection department they were used for holding a device-under-test (DUT) in place on a test fixture.  With ICs this wasn't necessary but with other items it was required to hold the DUT in place to minimize affecting the temperature or whatever.  https://www.destaco.com/clamping/manual-clamping/hold-down-clamps Where did we get them ?  why here: https://www.mcmaster.com/products/destaco-clamps/ I wonder if Destaco ever considered doing what Louboutin did with their shoes - Destaco clamps always had red handles :) https://en.wikipedia.org/wik...

I was looking at this patent: https://patents.google.com/patent/US8774317B2 it *appears* that it's not in force ?   Otherwise if it was still in force it would run until 2032 as I understand it. Everset is the company that got the NIST to change the modulation of WWVB, adding BPSK to give better coverage in weak signal areas. This has never caught on, must be the cost ?  Two antennas are used with the Everset - the only clock I could find using the Everset chip is this one from Lacrosse: https://www.ebay.com/itm/388836130899 A video on the Ultratomic clock: source:  https://www.youtube.com/watch?v=wqJA7hVym90 two interesting points from the video:  first, the Ultratomic clock uses two (or strangely four) C cells rather than the single AA cell in most "atomic clocks".  C cells are harder to find than AA or D cells but a big point for me: Energizer doesn't sell lithium primary cells (leak proof) in C size.  So that's kind of a deal cruncher for me - I need th...