We’re used to those high voltage projects which use a self-oscillating transformer circuit with a TV flyback winding, and we have even at times railed against them for their inefficiency compared to a real flyback circuit using the same parts. But what happens if the same idea is used to create a low voltage instead of a high one? [D. Creative] has a soldering gun project doing just this, making a low voltage at a very high current.
The video of the project is below the break, and while electrically it’s nothing unexpected, we’re taken by the quality of the build. All the parts come from scrap electronics, the main transformer is three ferrite cores with a piece of copper busbar as the secondary. The circuitry is built dead bug style, and it’s housed in a gun-style case made by hand from sheet Perspex. It takes 12 volt power from a laptop power supply, and feeds it to the oscillator which is perched up at the back of the device. The transformer fits in the “barrel”, and a pair of large capacitors fit in the handle. We expect it to get hot, but the duty cycle on these devices in use is probably low enough to keep it from melting.
We like anything that uses scrap parts to make something useful, and we’re particularly taken with the casing of this one. It looks as though the parts come from old switch mode power supplies, something we’ve been known to rob ourselves.
The induction part is a neat trick, even if it’s pretty low power. But the neatest part about this build is the ability to power it from 12 volts, untethered by a wall cord. That is useful.
So it’s almost a shame to then hard-wire it into a 12 V power supply. Especially since line-powered transformer-type soldering guns can be made easily, and more powerful than this, with zero electronics.
And is that a piece of copper wire as the heating element? A bit of iron fence wire should work better: higher electrical resistance (more heat deposited in the element rather than the power supply); higher thermal resistance (less heat conducted away from the hot end to the terminals); higher melting point.
Pretty much every transformer type iron I’ve ever used has a copper tip and I’ve never struggled to solder or desolder with them. I’m really not sure why I’d need higher temperatures unless I was intentionally trying to destroy stuff?
Never used a Weller with anything but copper, either their tips or 10 gage solid wire 12 in a pinch it don’t last nearly as long and runs hot so just use low. I haven’t bought tips in decades, I always save cutoffs. Won’t do without my gun at work or home. Big current things need more than a pencil iron.
lol. 50 years ago, pre internet or having a supply store in your area , we teenagers scrounged most every junk/trash pile we encountered.
That random couple feet of wire from a demollished barn service line, could have the next dozen homemade Weller tips hidden as the ground lead in the bundle!
P.S. a little gentle taping with a small hammer and some random bit if metal as a makeshift anvil and you could get a fairly good shape of the fold back or tip region.
A bit more work with an emory board or a small file and you could make a pretty decent tip. Just things ya do when resources and money are spread thin
Working with a 100 watt iron..
You had to learn to be fast with your heat application and do Good prep work on your joints before quickly tapping that 100 watt iron tip and getting it back off the joints.
Older eyes and hands nowadays. Thankfully 20 watt pens are a bit more forgiving for making up random headphone cords in my later years
Yet another “doing DIY only for views” youtube channel pumping out slop every few days.
If you’re looking for an actual transformer soldering iron, do yourself a favor, go to TME and search for ZDZ LT-75/45 (symbol
LT-75-45) or ZDZ LT-125 (symbolLT-125) for those tough jobs. Oh, and don’t forget to get some genuine Cynel 60-40 solder with its delicious rosin flux core.Those soldering irons are no-bullshit tools made in Poland. They will last you a lifetime and if a switch goes wrong or you drop it and it cracks – don’t worry, spare parts are available from manufacturer: http://www.zdz-lodz.pl/akcesoria-do-lutownicy-transformatorowej-c-2.html
I can definitely second this, I have ZDZ LT-75/45 manufactured in the ’80s, and despite of taking some serious abuse, and falling a few times, it’s still going strong without a single need for repairs
Ad.
You bet it’s an ad, and I’m not even being paid for it.
In this age of single use, non-repairable chabuduo crap from China we should promote honest local companies making honest tools designed to last decades.
The last video on this channel was 5 months ago, and everything was hand built in the video as far as I can tell. It’s neat. I don’t know why people like you come into the comments to tell people to just buy things.
it’s a 19V power supply from HP
Why build a low voltage soldering gun and then attach a power brick to it? It would be much more useful if it was run from batteries.
This thing is rather lightweight and less tiring to hold, this not 20 to 40 watts it up above 100 watts. That’s a real brick size of a power bank. If you are up an antenna tower or on a boat or such the battery power would be useful for sure. Workbench’s have power around most things happen there unless you do field work, then you’ll want to pack some real power on your belt for this gun.