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Simple, yet Confusing. Answered

I have this Soldering Iron. It takes 4 AA's @ 6V, and 8W or 11W. My reasons aside, I want to make it into an AC Soldering Iron now. I have various Plug-in adapters, and the one I chose Outputs @ 9V, 100mA. So sticking with the 11W setting, the Soldering Iron: > 1.83 Amps; 6 Volts; 11 Watts; And the plug.. > .01 Amps; 9 Volts; .09 Watts; So, what are my options? I got one.. find a plug with a higher current output :P



9 years ago

I suggest using a computer power supply. Usually you can get one for free when an old computer is being thrown out. Freecycle is another place where you're likely to find one. They can output 5V at over 20A, or 12V at over 10A. Plenty of power for a soldering iron!


9 years ago

I always start with complex projects first. It's how I learn and how I've always been. It works well for me- knowing 8 languages now and still learning ;P.
I also learn by experience and trial and error.. these types of projects are one of many. I know you're thinking "Trial and Error; Electricity; Death," yeah, well it wouldn't be the first time {by far}. I'm somewhat kinda sorta a safe-ish kind of person...!

Okay, so I have this other adapter here
12v @ 500mA = 6W and 24 Ohms

My main concern still remains, but here is is reworded for better understanding:
I want to provide sufficient power for this soldering iron using an AC wall adapter as a replacement for batteries. What can I do, using the adapter above and the iron's previously stated specs, to make them cooperate nicely?

& I just realized I misplaced a decimal in my last post. 100mA is 1/10 of an Amp, not 1/100.

you can connect resistor to it to leave just 6 volts to the iron. then iron gets 3 W and resistor 3 W. its probably not enough for the iron you can pwm it with some more complex electronics. itll get 6 W then you can mod the txformer and add some good cooling. then you may overload it (like pc overclocking) and get more W to the iron if you can get a computer power supply itll be best methinks

Narnar....a suggestion if I may, when you reply to someone in particular, use the reply button just below their post, and they will get notice that you are speaking to them, and it will appear below that person's post in here to. Making it easier to figure out to whom you are speaking :-)

Thanks, I was wondering why my own replies were concatenating upon each other. I thought that was just some sort of feature of being a registered member. =P

NP :-) We all have to learn sometime.

I was fairly familiar with the format as I had at one time a Bravenet forum I ran.....I kind of let it fall by the wayside though.


9 years ago

Okay.. so if I bump down the voltage to, for instance, 6 volts (and how exactly would I do that? I am only familiar with resistors which resist current, not voltage..), then that leaves me with > .01 Amps; 6 Volts; 0.6 Watts; and 600 Ohms; (Resistance calculated with Voltage and Current) Correct? If so, the wattage seems significantly low to produce the amount of power imagined for a soldering iron.. but I may be wrong.

As Kelsey is indicating, the most common way to drop that much voltage is to run the house current through a transformer (the amperage will increase with the voltage drop, however), and then you will have to use a bridge to convert the ac to some semblance of dc, a regulator and some clamping capacitors to smooth it all out, or as Digital suggests, just get a psu or wall wart with a similar output.

. If there is no circuitry in the iron (ie, just batteries, switch, and tip), then AC will work fine. Take the batteries out before applying AC. . A 1W power supply is not going to drive a 10W device. You need a 6V supply that will put out 2A.

Yes, I guess I wasn't clear enough in saying that I am using a wall wart, and that all of said outputs are from the indications on them.

You're familiar with Ohm's law (V=IR). Current is conserved (well, technically, electric charge is conserved :-), so what resistors do is introduce a "voltage drop" as the let the current flow through them. The drop in voltage is a change in potential energy; that energy has to go somewhere, and it comes out as heat.

So you could use a simple resistor with a massive heatsink to drop the voltage, or you could use a more complex power supply that doesn't waste energy or produce so much heat. If you aren't comfortable with electronics concepts at this level, this project may be too complex for you to start with.

computer power supply 3.3 / 5 V give it lower voltage since the power supply has allmost no internal resistance (and batteries have)