I recommend readers of the magazine is easy to count, easy to manufacture and very reliable electric soldering iron. At my house, for example, these range from “krohotulki” for work with microelectronics to powerful “ax” with which to patch a leaky metal tanks, repairing wells, filters and other large items. Moreover, the heating element of each electrical device is… the appropriate power resistor (type PE or PEV), powered by household outlet voltage is 220 V. the resistance, if they cannot be avoided, reactive, precise, capacitive, allowing to solve very complex electrical problem with the minimum dimensions of the devices.
As shown, for calculations in the manufacture of soldering with resistor heaters, it is sufficient to know Ohm’s law (I=U/R), the basic formula for power (P=IU) Yes tolerable to use four arithmetic operations.
Suppose that, having vitrified ПЭВ30 resistor with nominal value of 100 Ohms, you have decided on its basis to make a soldering iron from the mains voltage 220 V Referring to the above ratios, it is easy to determine the required data: current 2.2 A, power consumption: 484 watts. But…
Appearing in the name of the used resistor the 30-W parameter is power dissipation, which can PAUSO a long time (thousands of hours!) save, not appreciably Nicolaas, its own denomination. Mounted in the heater in the soldering iron (of course, with inserted copper core heat sink), this resistor has to dissipate power, many times superior to the passport.