Moderated
Re: Attached graphics (was: creating a zenner like floating point using BJT)
On Tue, Apr 8, 2025 at 05:12 AM, wn4isx wrote:
Well, in theory I'm an owner or so it says by the Home icon at the top of the left hand panel. I'm not sure why I was selected ...
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I think perhaps whomever granted me owner's status might ought to remove it because clearly I have no clue what I'm doing and all I've done is irritate people, something I don't mind doing if I'm right, something I hate doing when I'm wrong.
Calm down.? This won't do you any good because you left already.? But you shouldn't take this so seriously.
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Steven Greenfield made you one of the Owners of this group (and others he also owns).? He is the one who created this group.? That also makes him responsible for setting up the "rules" that the rest of us should follow.
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This particular "rule" does not seem to be stated anywhere obvious.? You can't expect everyone to read all 99560 messages here to find that one rule.? It ought to be out in the open.? I'm glad that you found it.
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Andy
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Moderated
Re: Attached graphics (was: creating a zenner like floating point using BJT)
Oops, I am sorry!
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Attachments ARE actually stripped from messages, in this group.? I had missed that setting, and anyway it does not work the way I expected.
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This group was already set to "Strip" attachments from messages.
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That setting has strange consequences.? Apparently, it strips them ONLY from the emailed copy of the message that gets sent out from the group's servers to most group members.? But it is NOT stripped from the copy of the message that is posted in the group's web copy of the message.? That is weird, IMHO.? Furthermore, there is no warning to the sender that their message was modified.? In my opinion, that's a bad idea, but who am I to judge?
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Andy
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Moderated
Re: Attached graphics (was: creating a zenner like floating point using BJT)
On Tue, Apr 8, 2025 at 05:21 AM, wn4isx wrote:
This is what I based my decision upon:
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Attachments are not allowed. Images and files should be uploaded to the Photos or Files area
That may be so.? But a message from two and a half years ago, buried in the archives, does not quite make it a Rule.? The fact is that attachments ARE allowed here.? They could have been disabled (by Steven Greenfield), but they were not.? Or perhaps the group's policy was changed since 2022 when he wrote that.? It's a bummer when old stuff sticks around.? [Mod. note: Edited because it was revealed that attachments are indeed "Stripped" automatically, even without any obvious Rule in a clear place saying this.]
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If it were a Rule, it should have been (a) stated as such on the group's website where people join the group, and especially (b) enforced by turning Attachments off.? But I see neither of those having been done.
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Andy
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Locked
One needs to know when it's time to leave
I joined this group because it looked like fun and I didn't expect it to take up a lot of time.
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In the main, it has been fun, some minor issues with one member but nothing insurmountable.
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I hope most of my posts have been useful and I didn't cause too much confusion trying to 'enforce' what I thought were the rules for posting graphics in this group. I am sorry for any angst I caused. I like rules, imagine what it would be like if we weren't expected to drive on the proper side of the road. [which is why I'll never visit England.]
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However I've taken a hard look at how I spend time during the day, what rewards I get versus the time spent, and changes that could make my life more satisfying, and, I've come to the conclusion being a member of this group eats up time that would be better spent listening to shortwave, playing guitar, or doing any number of other things.
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Therefore, it won't be necessary for any other owner to remove my owner status because I'm leaving the group effective immediately and my last act as an owner will be to lock this post. There isn't any reason for anyone to reply, especially if they expect me to see their reply.
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The email I used to join this group has turned into a spam magnet, I'm receiving upwards of 100 spam messages a day and I've waded through Micro$loth's inane 'close this email account' process. For reasons only known to Micro$loth it takes 45 to 60 days for them to actually close the account. I don't know if senders receive any notification the account is either closed or being closed.
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Moderated
Re: Attached graphics (was: creating a zenner like floating point using BJT)
On Mon, Apr 7, 2025 at 07:38 PM, Andy wrote:
Really?? Here does it say that?? Where are the "rules of the road"?
This is what I based my decision upon:
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Attachments are not allowed. Images and files should be uploaded to the Photos or Files area.
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Don't worry, I won't try to 'enforce' any rules from now on.
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I've read the help section on owners and it appears I can't remove myself from the owner's catagory, can another owner please strip me of the godlike power?
Thank you
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Moderated
Re: Attached graphics (was: creating a zenner like floating point using BJT)
Well, in theory I'm an owner or so it says by the Home icon at the top of the left hand panel. I'm not sure why I was selected and I was under the impression based on earlier messages that graphics embedded in a message were a big no-no.
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I based this on:
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Attachments are not allowed. Images and files should be uploaded to the Photos or Files area.
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Since Steven created this (and other) group(s), I foolishly assumed his word was final.
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?I wasn't trying to insult anyone, only trying to follow what I understood to be the rules.
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I think perhaps whomever granted me owner's status might ought to remove it because clearly I have no clue what I'm doing and all I've done is irritate people, something I don't mind doing if I'm right, something I hate doing when I'm wrong.
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Moderated
Re: Attached graphics (was: creating a zenner like floating point using BJT)
Graphics belong in the files section, please edit your post; delete and move the graphic to the files section.
If you don't I, or another moderator will be forced to delete this post.
Sorry, such are the rules of the road.
Really?? Where does it say that?? Where are the "rules of the road"?
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Graphics in the messages section use a disproportionate amount of memory.
Graphics use about as much memory no matter where they are.? Admittedly, it is true that emailed graphics files use a bit more memory because the bytes need to be converted to make them text instead of binary, but that is a moderately small overhead.
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Andy
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Moderated
Re: Attached graphics (was: creating a zenner like floating point using BJT)
On Mon, Apr 7, 2025 at 11:24 AM, wn4isx wrote:
Hum, on both of my net PCs and my wife's win10 and Mac, there is a graphic of the circuit in question. I guess Groups IO now automagically inserts graphcs from URLs.
There was both.? John23's message had a URL to a video, and he also attached a screenshot with red squibblies scrawled on it.? By visiting the message on the groups.io website ( 99943), you can see it, below the URL.? It is a big graphic, with lots of circles and arrows and a paragraph on the -- oops, not that, but lots of scribbled stuff. ?
In my email program, the screenshot did not display; just a small icon saying something went wrong.? I don't know why.? Something about Gmail, perhaps.
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Since this group allows attachments like that, and the group's guidelines say nothing about where to not put screenshots, I don't think john23 did anything wrong in that respect.? You can't criticize him for that.
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I wish there was a Groups IO "how this system works" along with detailed rules.
It works pretty much straight-forward.? In most cases, it just works, the way it's supposed to work.? Yet you need to understand that there are things beyond groups.io's ability to control.??But if you want to know more about groups.io, read away.? They have plenty of instructions, with a link to them in the lower left corner of your screen.
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As for "rules", that is what group Owners are for.? Owners set the rules for their group.
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Andy
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Moderated
Re: Attached graphics (was: creating a zenner like floating point using BJT)
To prove I'm not totally nuts (yea good luck with that Terry) I'm going do a screen print and post it in files under "IsTerryNuts.PNG."
Please view IsTerryNuts.PNG in the files section.
Now can someone explain how I can see the graphic when no one else can?
Somehow I doubt I'm that special or chosen by a higher power endowed with special powers and privileges.
No burning bushes, no tablets on human behavior.??
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OK for the technobabble....
My primary net PC is a HP Probook 4530 8G of RAM laptop running Windows 64 bit professional with no tweaking, my secondary net computer is a HP netbook I keep for "on the road" [doctor's offices and the like.] The PCs are stock with no tweaking.
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My wife has an HP desktop running Windoze 11 and a Mac running "only God knows or cares."
[I've spent the last 40+ years avoiding any Apple project. I met Steve Jobs once...once was enough to turn me off for all Apple products until the sun runs out of hydrogen. Yes it is silly but I value my pet peeves all the more because I have so few.]
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All 4 of these machines see what I show in the screen print.
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I am really confused here.?
How can a Youtube video display as a PNG still graphic?
How/why are our PCs showing what no one else sees?
And, have I made a complete fool of myself yet? If not, lots of time left.
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Moderated
Re: Attached graphics (was: creating a zenner like floating point using BJT)
On Monday 07 April 2025 11:24:33 am wn4isx via groups.io wrote: Hum, on both of my net PCs and my wife's win10 and Mac, there is a graphic of the circuit in question. I guess Groups IO now automagically inserts graphcs from URLs. Odd since it comes from youtube and is a is is "2.png."
I wish there was a Groups IO "how this system works" along with detailed rules.
I'm going to delete my "edit and move the graphic or this post will be deleted."
Thank you for letting me know the graphic isn't embedded in a message. No graphic showed up here, either. -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
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Moderated
Attached graphics (was: creating a zenner like floating point using BJT)
Hum, on both of my net PCs and my wife's win10 and Mac, there is a graphic of the circuit in question. I guess Groups IO now automagically inserts graphcs from URLs. Odd since it comes from youtube and is a is is "2.png."
I wish there was a Groups IO "how this system works" along with detailed rules.
I'm going to delete my "edit and move the graphic or this post will be deleted."
Thank you for letting me know the graphic isn't embedded in a message.
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creating a zenner (Zener) like floating point using BJT
‘Floating’ is a poor choice of words on his part. That node will have a voltage Vbe(T6) above the minus node. ?
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Moderated
Attached graphics (was: creating a zenner like floating point using BJT)
There were no GRAPHICS in his post. It was a URL to a Video.
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creating a zenner (Zener) like floating point using BJT
Hello , In the manual shown in the link the author says that the point I sighed in red arrow is floating at 2:46 and 32:20 time of the video.
How is this floating happening?
every potential needs reference, Why the pair of BJT shown in the red arrows is creating floating point?
Thanks.
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Re: Battery powered soldering iron
On Thursday 03 April 2025 06:49:27 pm benx618(g) via groups.io wrote: You might check out a Ryobi item:? 18v 120w temp controlled pencil iron (400-900° settable with knob) useful for electronics, etc.? Uses Ryobi 18v standard batteries.? Uses 'standard' interchangeable tips.? I use mine mostly for short mobile or outside location or electronically isolated tip iron use.
Ryobi model PCL946B = tool only.? May also come in tool/batt/charger combos too. Hm. We have a number of Ryobi tools and are fairly satisfied with them. I'll have to keep that in mind should the need arise. -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
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Re: Battery powered soldering iron
On Thursday 03 April 2025 04:11:49 pm wn4isx via groups.io wrote: What's funny is she uses a PC with a CAD program for quilting and a computer controlled "sewing machine" with zero issues. And she's never caused a 2M HT to lock up.
In our case she does things the old fashioned way, and I've seen some of the results. Quite the seamstress! Her sister next door has one of those computerized sewing machines and has had lots of trouble with it. Watching videos like Big Clive tearing things down it amazes me how they're sticking a microcontroller chip in so much stuff these days. Never had an HT lock up... I think it was P. J. Plauger who said something like "No program should leave its sanity at the mercy of its input." -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
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Re: Battery powered soldering iron
On Thursday 03 April 2025 03:58:35 pm wn4isx via groups.io wrote: On Thu, Apr 3, 2025 at 11:14 AM, Roy J. Tellason, Sr. wrote:
Wahl Isotip 60
Take a look at
I'm not 100% sure, but I think that I may have gone around with those folks before. They show a yellow, a gray, and a black one. Mine's red. I'd have to find it to be sure of the model number but I think it might be a 7800. The normal thing is a continuous slow charge when it's in the stand, and there's a white plastic bit on the side of it that you can use to reset the thermostat, at which point it goes into a quick charge mode with the temperature of the battery actuating the thermostat, with a quite distinctive click. The battery has a metal cup on the top end for that thermostat to sit in, so it's pretty unique, can't just stick a couple of cells in there. The page you link led me to this one: But the link given to send it to them for a rebuild leads back to that same page. I may try contacting them but at this point I have no urgent need for another soldering iron, so it's one of those round tuit things... -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
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Re: switching BJT from saturation into active mode
A BJT is inherently a current-controlled and -controlling device.
Ibe controls Ice, within the limits of the surrounding circuitry.
I have no idea why you don't want to use current sources if you
are after a device behaviour model. If there is another goal, it
would be a good idea to tell us, otherwise we can lead you to a
perfect but perfectly useless circuit.
To get the device in your earlier schematic into active mode,
you'll have to drive the base with less current than I(e)/Hfe.
This is known as "biasing a transistor" and is pretty standard
electronic design. Most good biasing schemes that I know of use
some form of current sources, since Vbe varies with temperature so
much. Do a bit of net search for "transistor bias" and related
terms; you should be able to come up with something useful.
In your original schematic (I'm not going to bother downloading
another), note that V1 is 5V and V2 is -1V. The base current of Q1
will therefore be somewhere around ((5V) - (0.6V) - (-1V))/(100ohm
+ 1kohm) = 4.9mA. If Q1 has an Hfe of about 100 (just a WAG,
understand), then Q1 will be capable of carrying? 490mA through R3
-- that WON'T happen given R3's value and the 5V from V1. To be in
active region, Q1's base current has to be less than 0.01 *
whatever current V1 can provide through R2 + R3.
If you _really_ want to use V2 and R1 to bias Q1, you'll have to
increase V1 to a positive value near V1 - V(b,e): so somewhere
around 4.0V to 4.5V. A base-emitter shunt resistor might also be
helpful, but that will be left as an exercise for the student.
Donald.
On 4/4/25 08:09, john23 via groups.io
wrote:
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Show quoted text
Hello,I prefer not to use current sources
A you can see In the attached photos and simulationI this I got
it to be in active mode? by tweaking the resistors .
I made few equations for the BJT shown in the photo ,could
you help me to develp a mathmatical way of finding the values
for setting the PNP into active mode?
Thanks.
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Re: Battery powered soldering iron
I’m in the UK. Those are available here, but not cheap… Nuno T. ?
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Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of benx618(g) via groups.io
Sent: 03 April 2025 23:49
To: [email protected]
Subject: Re: [electronics101] Battery powered soldering iron ? You might check out a Ryobi item:? 18v 120w temp controlled pencil iron (400-900° settable with knob) useful for electronics, etc.? Uses Ryobi 18v standard batteries.? Uses 'standard' interchangeable tips.? I use mine mostly for short mobile or outside location or electronically isolated tip iron use.?? Ryobi model PCL946B = tool only.? May also come in tool/batt/charger combos too.? - currently in stock or free deliver from HomeDepot (I'm in southern Calif near Los Angeles) list $50.??- currently in stock at DirectToolsOutlet dot com (South Carolina based, Ryobi authorized etc) $32 + shipping $15.? note occasional deals with free or 50% shipping.? ? -- Nuno T.
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Re: switching BJT from saturation into active mode
Hello,I prefer not to use current sources
A you can see In the attached photos and simulationI this I got it to be in active mode? by tweaking the resistors .
I made few equations for the BJT shown in the photo ,could you help me to develp a mathmatical way of finding the values for setting the PNP into active mode?
Thanks.
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?Steven AE7HD?
Gooey