What's this "Cold Heat" soldering iron?

"Jeff Wisnia" wrote: (clip) As my Grandpa Schlomo used to say, "If I'd swallowed a whole pack of Ex Lax and washed it down with half a bottle of mineral oil, I'd sooner trust a fart than trust a deal like that!" ^^^^^^^^^^^^^ Do you have a collection of Schlomo's sayings? How about posting more?

Maybe it uses some kind of rapidly-discharged capacitor. Like a spot welder, but without a constant supply of power.

Dunno how such a thing would work off of 4 AAs, though.

There are no capacitors that can supply significant energy that are not many times larger than 4AA cells.

The tip is simply resistive but split such that the circuit is incomplete until touched to a conductor (the wires you are soldering). An ordinary soldering iron wastes nearly all the heat it generates, so I suppose battery operation is plausible for small tasks, where this design cleverly minimizes the area and time that the heat is applied.

The patented device is very simple. Looks like you could make your own from pencil lead.

"The present invention provides a soldering iron with a graphite tip having two separate halves that are electrically isolated from one another. When both halves of the tip are applied to an electrically conductive material, such as the material to be soldered, an electrical circuit between the tip halves and an electrical power source is completed. Therefore, the tip can reach operating temperatures quickly. When the tip is removed from the joint, the electrical circuit is broken and the tip material may quickly cool to a temperature safe for human contact."

Well, maybe that's the catch. ;^)

Or maybe it's good for nanoscale soldering.

Eh, just a thought.

Thirty years or so ago a TV shop I worked in had a NiCad-powered rechargable gadget about the same physical size with a small tip. IIRC it heated up in around 20 seconds and cooled down enough to touch in less than a minute. We used it for working on circuit boards and on service calls. Good for a few joints on small stuff only.

A friend of mine just bought one of these at Fry's. I think it was about $25 or so. It's simply a resistance soldering iron - 2 conductive tips that are insulated from each other. When the tips touch a wire to be solders it completed the circuit and the current flow gets everything hot. As long as you're soldering relatively small wire (16 ga or smaller) it seems to work OK. The product packaging specifies to only use 1/32" dia solder. 4 batteries gave about 20 solder joints before it started producing cold joints. It does heat up quickly - just a few seconds till the solder will start flowing.

Robert

Jeff,

This sounds like a resistance soldering unit. The principle is that the leads to the clips are very large gauge wire, one clip goes on one side of the joint to be soldered and the other clip goes on the other side. The current flow then causes the work to heat very rapidly because, at least in theory, the mechanical joint to be soldered is the part of the circuit with the most resistance.

Probably the best application for this type of soldering is brass metalwork, rather than electronics or electrical wiring.

Here's a fairly good link that explains it a little better:

If indeed this is what the unit you've described is supposed to be, then I'd say it isn't a very serious one. Resistive soldering units are ordinarilly based upon a huge power transformer that can deliver an enormous amount of current 'cause, for all practical purposes, you're using a short circuit to heat the solder joint.

HTH.

Scotty

*** This reply was written us> For the past week or so I've been seeing TV ads for a little "Cold Heat" < SNIP >

On Sun, 11 Jul 2004 21:52:18 GMT, "Siggy" calmly ranted:

They're $19.20 from QVC (+ shipping), replacement/different tips are $10 each, and batteries go quickly. Hmmm, fun toy but expensive to use. A nice little 6v gel cell would make it more handy at the expense of some portability.

They state minimum of 760 welds per charge on the site, too.

C'est la vie.

-------------------------------------------- -- I'm in touch with my Inner Curmudgeon. --

Comprehensive Website Development ============================================================

That's just what I was thinking about when I said "soldering tweezers". They've been around since G-d was a little boy. Here's some from American Beauty, they're called "pliers", but the principle is the same:

Frankly, I doubt if that patent would hold up against a determined infringer, there's just too much prior art on that kind of carbon resistance soldering. The patent examiner must have had a hot date that evening and figured it would take less effort to accept the claims and let the patent get granted than to have to collect and document all the reasons why it wasn't really an "invention".

Jeff

Only a few that I remember, but not enough for a book or even a column.

*************************************************************************

When someone did something unethical or low class Schlomo would usually say, "Vot do you expect from a pig but a grunt?"

When age started taking its toll on him he'd grumble, "Ach, ven you get old, everything either dries up or leaks."

But the one thing he said which changed my life forever was,

"Never waste an erection."

*********************************************************************

I miss Grandpa Schlomo....

Jeff

Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"If you can smile when things are going wrong, you've thought of someone to blame it on."

Yall can do the exact same thing with your basic old fashioned Weller loop style soldering gun, by simply cutting the loop in the center. Shrug..works great for soldering coax connectors and other type stuff. Works good on wire too.

That rifle hanging on the wall of the working-class flat or labourer's cottage is the symbol of democracy. It is our job to see that it stays there. - George Orwell

IIRC an article on resistance soldering appeared in Popular Electronics around fifty years ago. It involved a car battery, two heavy leads with alligator clips, and a lead pencil, or if you preferred two lead pencils. Gerry :-)} London, Canada

Boy does that bring back memories. I used one of those to assemble about a zillion AN3102 3106 ( I think ) connectors in the winter of 1953/54 as an engineers assistant. Often wished I had one at home but when I finally could afford one couldn't find it for sale. Havent checked the link but sounds like they may still be around. ...lew...

You must mean something like this?

Extremely handy for quick repairs! We had 2 or 3 of them in a shop I worked in for 20 years.

Best Regards, Keith Marshall snipped-for-privacy@progressivelogic.com

"Even if you are on the right track, you'll get run over if you just sit there." - Will Rogers (1879-1935).

clip

I've had a lot of battery-powered portable irons, starting with the original Weller Iso-tip back in the late '60s/early '70s when I was doing a lot of electronic repair. They were good for working on static-sensitive and heat-sensitive components and remote jobs, but inevitably the battery would run down mid-job. I also had to replace the battery packs for $20-25@ every couple of years, the tips would last maybe 6 months before they got eaten through, even with Ersyn Sav-bit solder. When the catalytic butane irons came along, I got one of the original, made-in-Ireland, Portasol units and never went back to an electric iron for remote on-site work. I think they're still the best bang for the buck. You do have to watch what you're doing if you're using it on a car, a gasoline fire could ruin your day.

For butane, I go to the local dollar store, they've got large Korean-made butane fills for $1.39(used to be a buck, though), like a large spray paint can in size. One can lasts a long time, I probably get at least a year's use out of one. The local supermarket gets like $4.50 for one of those dinky thumb-sized Ronson fills, I think it's to either discourage smoking or to encourage the sale of their house-brand disposable lighters.

Stan

I used a Wahl Ni-Cd soldering iron in the mid 80's when working on instrumentation for power station performance tests. Dead handy for repairing connections in pressure transducer cables while sitting on pipe-hangers 80' above the floor! I did almost s*1t myself on one occasion when unpacking my stuff after flying home. I discovered that the lock on the switch had failed and the iron had done its best to set fire to my suit case in the plane's hold. After that I always took the bit off the iron when travelling.

Mark Rand RTFM

This seems to be the patent on this device ( the link needs to be on one line to work ).

(Grigore+AND+Axinte)&OS=Grigore+AND+Axinte&RS=(Grigore+AND+Axinte) Jim

On Mon, 12 Jul 2004 16:06:53 GMT, "Keith Marshall" vaguely proposed a theory ......and in reply I say!:

I have to disagree. It's not uncommon to be the only one on the right track!