Although 60/40 solders melt at approximately 200 degrees Celsius, the temperature of the tip of a soldering iron should be approximately 370 degrees Celsius. It is vital to do this in order to swiftly establish a good connection without running the danger of scorching delicate components. When working with temperatures of this magnitude, it is important not to keep the point of the iron pressed on the joint for an excessive amount of time. Unfortunately, at this temperature, the tip oxidizes very quickly, and as a result, it needs to be cleaned often. This circuit can be of assistance in that regard since it maintains a temperature on the soldering tip that is slightly lower than 200 degrees Celsius even when the iron is not in use. When this occurs, oxidation is reduced to a negligible level, and the soldering iron can be brought back up to temperature in a matter of seconds whenever it is required. Due to the thermal inertia of iron, the temperature at the tip of the iron does not change during a regular soldering operation, even while the iron is allowed to return to a state of rest for only a little moment. Both the circuit and the working

The circuit for the soldering iron tip preserver is depicted in Figure 1. The circuit is driven by two 555 timers that are referred to as IC1 and IC2. IC1 is wired in a monostable design, which allows for an initial warm-up time of around forty-five seconds. This allows the iron to reach the necessary soldering temperature. At the conclusion of this time period, its output pin (3) goes high, which makes it possible for IC2 (which is wired in an astable configuration) to turn the iron on by using relay RL1. At this location, the temperature rises rapidly for one second out of every six. When the iron is in the stand, the values of resistors R5, R6, and capacitor C3 determine the duty cycle. Electrical connections P1 and P2 are able to detect whether or not the iron is positioned properly within its stand. Because the base of T1 is drawn down when the iron is in its resting position, T1 does not conduct when the iron is in its resting position. On the other hand, if the iron is not on its stand, T1 will conduct, which will pull pins 2 and 6 of IC2 high and prevent it from functioning properly. During this time, pin 3 of IC2 is low, and as a result, the iron receives constant power through the normally-closed contact of relay RL1.