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

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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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.

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In that case, you have to reduce the base drive. Separate bias and signals on the base would probably help.

I would change the series V2 and V3 into one current source - the DC offset is the bias and the Amplitude provides your signal. You can .STEP the DC offset to set different bias conditions.

Donald.

Seems a very good product. I'll consider it.

Thanks

Nuno T.

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On Thursday 03 April 2025 09:40:58 am acnestis via groups.io wrote:

Who knew that a fault in the radio would stop the passenger-side window from working?? The amount of digital electronics in modern cars is astounding (bordering on criminal.)

Yes!

I am not looking forward to ending up with something newer, though it's only a matter of time with one of our vehicles heading for 200K miles and showing some rust. The other one is approaching 150K. On one forum I participate in, there's a thread entitled "De-Crapifying cars", where the poster details a bunch of nonsense that he had to deal with in his Subaru, which basically took them off my list of brands to consider.

--
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

On Wednesday 02 April 2025 10:30:03 pm wn4isx via groups.io wrote:

An informative review can be found at


Looks very impressive.

It does. But although they mention a $26 price in there, the links to buy one are at $40 or so.

And what's with the default to conical tips in so many cases? I notice in that review that they mention "chisel" and "bevel" as being the ones they found most useful, and I tend to favor a chisel tip myself, where you can use a corner, an edge, or a flat to control how much heat goes into what you're trying to solder. I can't see a way to do that with a conical tip.

My bench iron at this point is the kind where you can screw a heating element into an edison socket in the handle, and screw various tips on to the heating element. I have a few assorted heating elements, and a couple of different handles. One of those was purchased at Radio Shack, and the rubber where you grip it has gone wonky, typical of their products. I think the original brand was Ungar, but I think they got bought out by Weller? My favored tip is a PL-113 (iron plated). So a while back I wandered into a Radio Shack store (when we still had some around) looking for a new heating element, or something, and they no longer carried that kind of an iron. What they did have was every single iron in the store had a conical tip on it, which I didn't want. I ended up ordering one online from someplace, temperature controlled and a 3-wire cord so the tip is grounded, which my older iron ain't. I haven't used it a whole lot, and am not overly confident in its ability to handle this PL-259 I need to solder here. I'll probably break out my Weller gun to deal with that one...

--
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

On Wednesday 02 April 2025 10:24:42 pm wn4isx via groups.io wrote:

I am really tempted, the price is reasonable, the power requirements practical and it avoids the risks inherent with an open flame.

It does look tempting, but that 30 day warranty put me off...

Oh, can you crash the OS? I ask because my wife has killed everything from windup watches to laptops simply by touching or holding them.

And no I don't believe some people have odd magnetic fields or whatever because I can measure almost everything and tests show she is a normal person...who just kills even primitive tech. I often wondered how on earth she can drive a car with 5 CPUs, but it gave me a headache so I gave up wondering and wrote it off as one of those mysteries of life. After all, she does love and put up with me and has for 46 years.

My late lady was like that. When working at a call center in the area, she hit some key or combination of keys on the terminal she was using and not only took down the whole call center, but also the two other ones that William-Sonoma had running at the time. It took them a few hours to get things back up again.

One or another of the youtube channels I watch had a similar iron with oled display and all. I don't recall the brand, nor do I recall what specific channel that was. They seemed to do all right with it, but I'd look around for something other than that one.

--
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

On Wednesday 02 April 2025 02:19:32 pm Nuno T. wrote:

Looking for good recommendations on a battery powered soldering iron.

Precision work is a requirement, doesn't need to work for hours on end,

1/2 hour every now and then is enough.



Any recommendations from your experience?

I have a Wahl Isotip 60, so called because it'll charge up in one hour. It needs a battery, and the battery is no longer available, so I can't use it. When it did work, it worked well, but it's currently useless...

--
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

开云体育

V2 is turning the Q1 on very hard, such that it is in saturation, and Vc (product of Ic and R3) is quite large. If you don't want Vc to be so large, you have to reduce the base drive (V2/R1) of Q1 or divert some of that current away from the B-E junction.

What is this supposed to do?

Donald.