temperature-controlled soldering iron

Electronic temperature-controlled soldering irons offer a number of advantages over continuous heat types: delicate components are protected against thermal damage; they permit the use of higher wattages, thereby eliminating the danger of dry joints when working under heavy load conditions; and finally they increase the life of both heating element and bit. The following circuit is for a thermostatic control unit, which is both easy to build and uses standard components. Suitable soldering irons containing a built-in heat sensor are readily available from a number of different manufacturers.