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Complete Your Profile- GaryD96 commented on titaniumw41's instructable $10ish DIY Variable Temp Soldering Iron Controller1 year ago
- GaryD96 commented on titaniumw41's instructable $10ish DIY Variable Temp Soldering Iron Controller1 year ago
Ok I made it, and I did a little experimenting. Bottom line is power is V^2/R where power is power dissipated by iron, voltage is the voltage applied, and R is the resistance of the soldering iron. So I measured the resistance of 3 "30 watt" soldering irons hot and cold and found this:Soldering iron 1, 490 ohms cold, 550 hot, iron 2 500 ohms cold 510 ohms hot, iron 3, 650 ohms cold, 550 hot. Anyhow when averaged, that's 550 cold and 540 hot, and I'll just say 545 ohm average altogether. So bottom line is a "30 watt" soldering iron has about 545 ohms resistance, and doesn't change a lot with heating.That leads to the following chart:P=V^2/R ("30 watt" soldering iron)22 watts for 110 volts15 watts for 90 volts10 watts for 75 volts5 watts for 50 volts1 wat...

see more »View Instructable »Ok I made it, and I did a little experimenting. Bottom line is power = V^2/R where power is power dissipated by iron, voltage is the voltage applied, and R is the resistance of the soldering iron. So I measure the resistance of 3 "30 watt" soldering irons hot and cold and found this:Soldering iron 1, 490ohms cold, 550 hot, iron 2 500ohms cold 510ohms hot, iron 3, 650ohms cold, 550 hot. Anyhow when averaged, that's 550 cold, and 540 hot, and I'll say 545 average altogether. So bottom line a "30 watt" soldering iron has about 545 ohms resitance, and doesn't change a lot with heating.That leads to the following chart: P=V^2/R ("30 watt" soldering iron)22 watts for 110 volts15 watts for 90 volts10 watts for 75 volts5 watts for 50 volts1 watt for 25 volts.S...

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Here is a little project I did. I scanned the internet for various wattage soldering irons, the less expensive types and looked at their wattage/power rating and temperature. Then I plotted temperature vs. wattage/power. And found temp vs. power to be Temp = 10*power + 300 (in degrees farenheit), or Temp = 10*V^2/R + 300 where R is the resistance of the soldering iron as measured with an ohmmeter. You can also infer the resistance for a soldering iron by the following formula power = v^2/R where v = 110 v and power is the power rating listed on the iron (this is approximate). Anyhow after all that I made out the following chart which can be overlayed onto a dimmer cover plate. I have not tested this but you get the point, these are estimates. Additionally, these irons aren't temp...

see more »Here is a little project I did. I scanned the internet for various wattage soldering irons, the less expensive types and looked at their wattage/power rating and temperature. Then I plotted temperature vs. wattage/power. And found temp vs. power to be Temp = 10*power + 300 (in degrees farenheit), or Temp = 10*V^2/R + 300 where R is the resistance of the soldering iron as measured with an ohmmeter. You can also infer the resistance for a soldering iron by the following formula power = v^2/R where v = 110 v and power is the power rating listed on the iron (this is approximate). Anyhow after all that I made out the following chart which can be overlayed onto a dimmer cover plate. I have not tested this but you get the point, these are estimates. Additionally, these irons aren't temperature controlled, I know you have to take into account thermal mass, heating and cooling rates, the mass of the thing you are soldering etc. This is more or a less an estimate of the initial temperature at the tip after the soldering iron has been fully heated and before any solder is melted. There is plenty of room for criticism about the above idea and template, which is not very accurate and certainly not temperature controlled. But I think if you use this to set a maximum temperature, it could be helpful, and is probably more useful to estimate a maximum temperature and then solder an item that has a much lower thermal mass than the iron. Which is a very common situation. Bottom line is, I'll use it to cut my 60 watt or 30 watt iron down to 15 watts, which is safe to solder most common electronic components. See faceplate below: