Soldering Iron Temperature control

Plugging a soldering iron into a rheostat (or temperature controller) does NOT reduce the temperature. It reduces the amount of electricity coming in but doesn't change the temperature the iron will heat up to. It will just take longer to heat up. It's the same as the tap on your sink. Turning the tap down will make the water come in slower, but the water will still fill up your sink. It'll just take longer to fill up.

1. Basic Concept of a Rheostat:

• A rheostat is a variable resistor. It adjusts the resistance in a circuit, which in turn controls the current flow.
• By increasing the resistance, the current flowing through the circuit decreases, which reduces the power delivered to the soldering iron.
• Conversely, reducing the resistance increases the current flow, increasing the power to the soldering iron and therefore the temperature.

2. Operation with a Soldering Iron:

• Input Voltage: When a soldering iron is plugged into the rheostat, the device controls how much of the mains voltage reaches the iron.
• Power Control: Turning the rheostat's dial changes its resistance, altering the amount of current flowing through to the soldering iron’s heating element.
  • Higher Resistance = Less Power = Lower Temperature.
  • Lower Resistance = More Power = Higher Temperature.

The most popular iron right now is Hakko Fx601.  It comes with an internal thermostat.  A thermostat automatically maintains a set temperature.  That makes it way easier to learn to solder with a nice line.  If you don't have to constantly adjust for your temperature you will have an easier time.  

Not that there are not reasons for an iron with a rheostat.  One is price.  Not everyone wants to pay over $100 for an iron when they are first learning.  This person can buy an inexpensive 100-watt iron and hook it up to a rheostat and find out if they like the hobby. 

100 Watt Pro Soldering Iron – Stained Glass Express

Stained Glass Express