Science/Engineering/Technical forums

Teardowns of cheater-cheap versions of these have been done to death on youtube. Dunno what flavor this one was, but... This was running my forepump for the fusor. Basically it was wired so either the turbo controller could activate it whenever the power needed to spin the turbo when past some (programmable) number, and turn it off below some other programmable number - or I could force it on or off manually with a switch. As well as the turbo speed itself being programmable, so that at slower speeds, it takes more gas present to be hard to spin etc. Nice system. But all they gave you was their version of a logic level (24v) and the rest is up to you.

Believing that of course a solid state relay has to be better than something with moving parts, back at the beginning of lab time when I built the basic system, I used this guy to change that logic level to 120v on/off for that forepump. Not sure what triggered this failure, actually, as it had worked for some years, and so has the rest of the batch of 10 I bought at the same time in various uses (2 control my Volt charger system). This never even got warm in this use that I could tell. Until it obviously got REALLY warm.

My best guess is that vibration eventually loosened the screw...and we had a high contact resistance there - or something similar happened inside, if it had been too cheap from the beginning, I'd think I'd have noticed it getting warm.

Of course, being put in at the very beginning of things, when the setup was far simpler, meant it's now really hard to get to. I had kinda clip-leaded and duct taped in a crummy replacement, but yesterday finally really changed it out to another "real I hope" SSR, which also doesn't get warm in testing. Along with a new battery to turn it on in "manual force on" mode, the old CR123 had worked for some years but...maybe it was the problem, but I doubt it, it had fried overnight while in auto mode - this is the mode my fusor spends almost all it's time in. Slow turbo rotation - around 133 hz (800 something is max) but turning on the forepump when we get to around e-3 mbar - usually when I check it's e-6 or -7 after sitting that way awhile. Saves wear, tear, and electricity, and that tank hasn't been opened for a really long time - I suspect it's really clean in there by now.

The interesting rhetorical question is:
Why did any of us getting into STEM - myself an engineer, then physics, with tech and chemistry along the way - think that this absolved us from having to crawl around in awkward spots showing our butt crack to the sky, aches and pains no extra charge? If it's computers, it was running coax, then catN cable, or digging into a tower under a bench for a VGA cable that got loose. And on and on.

I hear plumbers get paid well for that! And they probably do less of it!

Why did any of us getting into STEM - myself an engineer, then physics, with tech and chemistry along the way - think that this absolved us from having to crawl around in awkward spots showing our butt crack to the sky, aches and pains no extra charge? If it's computers, it was running coax, then catN cable, or digging into a tower under a bench for a VGA cable that got loose. And on and on.

ROFLMAO

So true, especially in the radio broadcast industry where management says "We can fit one more transmitter in that building", although studios seem to have more of the "crawling on your hands and knees" to get at a buried connection. Best thing to come along was the new LED "headlights", so that you have both hands free and can see what you are doing under that dark console desk.

Not to quote a crappy TV series or anything, but "Winter is coming" and I'm trying to get ready. Wood is a great battery for heat, and electricity is a great thing to run chainsaws with - the only issue with these is that without a clutch to slip, you have to be a little careful not to pull chains apart - no kidding. People used to those big heavy gas saws freak out when they see what 3 _real_ horsepower will do. This one was only 70 yards from the shop, so I didn't even need a portable generator (which will only run my 2 hp electric saw - barely). That's 64 meters for those who can only do things in powers of 10. Easy extension cord range for this little guy.

Of course, if you're more into dry British humor...The Register tech site has it's own units system. So here's their take.
Reg
Linguine
457.2175
Double-decker bus
6.9433
Brontosaurus
2.9122
Devon fatberg
1.0002

/////
for reference ... https://www.theregister.co.uk/Design/pa ... erter.html

I was so damned disappointed in GoT. In fact, damned mad that they barfed the last season so horribly.

I wish winter could come to Texas this year, though. Anything under 95 feels positively balmy, and the 70 degree mornings we've had recently are almost cold...

Ah, I never watched it, so...I got into it after hearing about everyone else being pissed off...and going backwards, as it were, it was funny...
Glad to hear you're in the land of the living, I'm on here to activate a couple new users....

Yeah, I'm alive, but it's been too damned hot to want anything but gazpacho or ice cream. I'll show some signs of life when it's below 80..

I probably don't agree with anyone all the way....but Sabine is one of my favorite skeptics/caller of BS on the high falutin academic theory world. I think she's worth at least a little time and attention, if only to make one think.
https://www.youtube.com/watch?v=5foUTeRdqII

And just for the fun of scrambling things up on the random thread further - "a homesteader's work is never done". Managed to drop that within a foot or two of the desired spot - right where my truck *was* before I moved it out of that driveway...Once this is trimmed and bucked and split, I might be done with the firewood part for this year. But now it's lunchtime and a wait for the shade to move to where I want to work on this. And I still have all my arms and legs - fun when stuff this big bounces around. Almost exactly 18" diameter at the base...that's a lotta wood there.

Well, I have a new security guard at my shop door..um. Hope I'm not the threat they are guarding against.
Actually, it's been peaceful coexistence for awhile, but I just stumbled across a pretty neat video on YT, showing a guy removing a huge nest of these - which this one originally was before a skunk dug it up - these are the survivors. I figured to document this before I tried what this guy did, in a lot easier state - they're going to be cold and asleep when I use the magic vacuum tool on them.
I don't have a nice suit like this guy. That was a pretty slick trick on his part.
https://youtu.be/cMrwlSh81AU

When we had a yellowjacket underground nest by our back door, we took it out by pouring ammonia down the hole (the ammonia bottle taped to a rake, so it could be done from six feet away) and an assistant quickly covered the hole with a shovel full of dirt. We did this near the end of civil twilight so that most of the critters would be at home, but we could still see what we were doing.