How to Create an Adjustable Soldering Iron




Intro: How to Create an Adjustable Soldering Iron

Recently my old soldering gun spoiled. I open the casing and try to repair, but I think the problem is the heating element, which is not repairable. So, its time to get a new soldering tools. After some research, I bought an Antex branded 25W soldering iron, at price of RM70. Initially, I am thinking of getting a 18W or 16W Antex, but what they have there at that time is 25W, and I simply take it.

After I power it up and do some testing, I found out that the 25W is a bit over heat compare to my old soldering gun. I am a bit regret about choosing 25W, but I don’t think I can return it back because I already power it up and the colour changes of the heated tip is very obvious. So, I decide to add a dimmer to the soldering iron to make it adjustable.

Step 1: Using a Dimmer to Adjust the Power

To enable the adjustable power for soldering iron or soldering gun, you will need a dimmer (any home lighting dimmer will do). For me, I get an UMS 6600S Dimmer Switch from an electrical store. The wiring instruction do state that the max power supported by the dimmer is 600W, so, my 25W shouldn’t be a problem for the dimmer.

Also, you will need a box for the dimmer as a protection to the wiring. You can this kind of box (I am not sure what it is called) in a normal electrical store.

Step 2: Cut Small U-Shape at the Box

From the pictures, you can see that I do cut a small U-shape clearance for the in and out wire. I do it using a cutter, you can try to use a drill (maybe you can drill holes for in and out wire), and please be careful while doing this.

Step 3: Wiring of the Dimmer and the Soldering Iron

Now, proceed with the wiring according to the Wiring Instruction. Simply replace the Lamps with your soldering Iron.

Step 4: Completed Adjustable Soldering Iron

The complete adjustable soldering iron.

Please leave a comment if you have any suggestions or better solution.




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    9 Discussions


    10 months ago

    I bought a dimmer switch (600W/250V) , connected the live (brown) and switched live (neutral-blue) wires the same how the instruction says but the soldering iron doesn't heats. Waiting for about 20mins when before was ready to go after 5mins. Any advice?????


    2 years ago

    If you use the double / twin gang box then just hook your ground to the regular socket / outlet ground and dont forget the dimmer often needs one to but don't just use bare single earth use an insulated cable.


    2 years ago

    Made a few of these over the years. Both for 240V UK and here now in Canada for 110V. I usually get a double box and mount a socket (outlet) on one half and the dimmer on the other half. Advantage is you can use it for other electrical devices too as there is no need to take off the plug. Have used them for fixed speed dremel type drills or where I needed a hair dryer to operate a lot cooler than the simple two setting switch allows. Also occasionally used them to lower input voltages on adaptors to lower the output voltage but that can be a bit hit and miss depending on the internal construction of the power supply. Just about to build another and have the parts but figured I would see what was on here in case there were any new ideas.

    I find that the controllers here for 110V have a drop off / stall point so that I often need to be at least quarter turn before I get any action. Also watch out for the newer ones as they are often electronic and don't always work well. Older style like this instructable are the best with simple rotary controls.


    3 years ago on Introduction

    i plan on making this but where dose the earth wire go dose it just go directly in to the soldering iron like the neutral or do you have to mount it anywhere different.



    Reply 6 years ago on Introduction

    I plan on doing this soon. How can I figure the different watt settings to properly label the box?


    Reply 5 years ago on Introduction

    It might be easier, and better, to calibrate, and label, dimmer with the temperature. I saw some digital thermometer for soldering irons that measure the temp of the tip by placing the tip on the sensor pad. They were about $15.00US. But you can get an adjustable soldering iron for less than that (don't know about the quality), not a soldering station, just a soldering iron with a temp adjustment knob on the side of it


    Reply 4 years ago on Introduction

    Labelling for temperature is a useful suggestion but a dedicated digital thermometer for soldering irons sounds preposterous. Any good infrared thermometer will measure up to 500° C—just remember to aim it at the tip.