Soldering Iron Tip Preserver

Although 60/40 solder softens at about 200°C, the tip temperature of a soldering iron must be at about three70°C. This is important to make a just right fast joint, without the danger of overheating refined parts because the iron needs to be saved on the joint for too long. Unfortunately, at this temperature, the tip oxidises swiftly and needs constant cleaning. Thats the place this circuit can help - it preserves the soldering tip to simplest beneath 200°C while the iron is at leisure. Oxidisation is then negligible and the iron will additionally be introduced again up to soldering temperature in just a few seconds when needed. In addition, standard soldering operation, where the iron is returned to leisure only momentarily, is unaffected on account of the thermal inertia of the iron. Two 555 timers (IC1 & IC2) type the heart of the circuit. 

Circuit diagram:

Soldering Iron Tip Preserver Circuit Diagram

IC1 is wired as a monostable and provides an initial warm-up time of about 45 2nds to deliver the iron as much as temperature. At the end of this era, its pin three output switches high and IC2 (which is wired in astable configuration) switches the iron on - by means of relay RLY1 - for approximately one second in six to care for the standby temperature. The presence of the iron in its stand is sensed via electrical contact between the 2 and some slight modification of the stand may be important to be successful in this. When the iron is at relaxation, Q1s base is pulled low and so Q1 is off. Conversely, when the iron is out of its stand, Q1 turns on and pulls pins 2 & 6 of IC2 high, to inhibit its operation. During this time, pin 3 of IC2 is low and so the iron is constantly powered by the use of RLY1s normally closed (NC) contacts. Note that the particular soldering iron that the circuit was once designed for has its personal 24V supply transformer. Other irons might want different energy provide associations. The warm-up time and standby temperature may additionally be diversified by way of altering R2 and R5, as essential.

Author: Alan March - Copyright: Silicon Chip Electronics