Variable Voltage Control

Sliding it upwards increases the brightness of the light . Therefore
it is not decreasing power but increasing it, ergo, this curcuit does not work for what I want.

Ahhhh, but sliding it down does dim the lights! Right?

The light dimmer cannot truly "add power to the outlet" what with those pesky thermodynamic laws and all.

Think of it like this:
If your dining room lights had just a simple on/off toggle switch, they would either be OFF (no brightness/no power) or ON (full brightness/full power).

All the dimmer is doing is giving you a range of brightness/power somewhere between OFF and ON as selected by the slider/knob.
It does this by allowing the load (the lights in this case) to only get power for a certain amount of time.....some fraction of the 60Hz cycle.
It does not change the maximum amplitude of the voltage supplied to the load, just the amount of time the load gets power.
It's like a little man throwing the toggle switch on and off really fast.....so fast you can't see it!

Once turned on, those lights look like a simple resistive load. They pull some amount of current based on their resistance.
Your "heating element only" soldering iron will also look like a simple resistive load.

You should be able to control the heat of your soldering iron very well with this approach.
(........as long as you follow the advice in post #3 above)

-brino
 
Last edited:
Why not make it a fun project? Get a temperature controller with solid state relay and thermocouple. Mount it in a box and control temperature to with a couple of degrees. This project will get you to use CAD, Milling machine, lathe, and some hand tools. You will learn how the controller senses heat, self adjusts for accuracy, and controls using little blasts of power with the solid state relay.

I did the exact project for 3D printed parts needing precise control of the temperature when inserting threaded inserts into printed plastic parts using a soldering iron.


It seems that by some reason I have those parts on hand. But as usual I don't know how to use them.
Can you provide a simple schematic, like where does the power come from?





View attachment 244055
 
Get a battery powered soldering iron and just keep taking the individual cells out until you get the right temperature.
I've got too much money in this allready to buy another iron. I've bought three so far and a new digital mulimeter.
 
I have a bunch of these

th

It's a variac, a variable transformer. I have perhaps 10 like new. I will draw a schematic and throw it in the box. You pay shipping and I will give it to you for free.

I would stick it in a Post Office box that sends flat rate.

If that sounds good to you send me a private message.
 
O.K. Lets get back to my first post regarding the dimmer switch circuit.
I searched "how to measure voltage" found too many to be clear but, most were like this image, is this correct?? If not put me on the right road.View attachment 245911
 
No attachment!

Personbally, I use a 50 or 60 watt iron. My 30 watt irons were way too slow. But I think you are overthinking this. If it were me, I would adjust the dimmer until I got the results I wanted. I have two variable temperature irons,one with a temperature meter and the other without. Either works for me as I judge the setting by how the iron performs.

When I solder pc boards, I will turn the iron all the way up to 500 C because I m making about 1 solder joint a second and pulling heat away from the tip fast enough to keep the temperature down. On the other hand, if I am doing some delicate work, I will set the temperature at around 300 C so I don't overheat my work and the iron doesn't oxidize.
 
Have you tried your dimmer circuit with a lamp plugged in instead of an Iron to see that it actually dims?
If it doesn't work then you must have miswired it or the dimmer is bad.
Mark S.
 
I have decided to give this project a rest for now. Thank you all for the help you have given me.
 
Back
Top