Tin welding equipment is one of the most important tools of an electronic engineer or an electronics repair person. Here I will guide you to a completely manual welding station. You do not need to be a new electrical engineer to do it, just as you like and want to make yourself a meaningful and handy device to repair such as the equipment in your home.
For basic items such as plugs or light bulbs … you do not need to use a soldering station, but for more complicated parts involving electronic circuits, welding stations are an indispensable tool. .
For welding stations, controlling the temperature is very important, especially the integrated circuits (because the electronic components will only withstand a certain temperature level, if the temperature is not controlled). friendship may cause the component to fail. In addition, the welding station must also be maintained at a fixed temperature level regardless of the external conditions.
Welding station design
Some of the advantages of this design are:
Flexibility: The welding station is designed to use a more flexible and flexible adapter than the use of transformers and bridge rectifiers as conventional welding stations.
Simple design: I do not want any LCDs, unnecessary LEDs, or buttons. I just want a 7 segment LED display to see the current temperature and a desired temperature knob.
Popular: Use 5-pin jack for solder, which makes welding station completely compatible with Hakko welding hand.
The best method to control solder temperature is to use a PID algorithm, which is used for anything that requires automatic tuning and this algorithm is widely used in the industry.
First of all, let’s talk about PID. For the sake of clarity, I will explain in detail and here is the soldering station. The microcontroller will adjust the heat of the solder through the PWM based on the following formula:
u (t) = MV (t) = Kpe (t) + Ki∫0te (τ) dτ + Kdddte (t)
where the adjustment parameters are:
Proportional gain, Kp
The larger the value, the faster the response, the greater the error, the larger the offset. A very high rate of interest will lead to instability and oscillation.
The larger the value, the faster the reduction is. In turn, the greater the overshoot: any negative noise that is integrated throughout the transition response must be eliminated by positive integrals before reaching steady state.
The larger the value, the lower the overshoot, but slows down the overcurrent response and may lead to instability due to amplification of the signal noise in the differential error.
I use the 8-bit Atmega8 microcontroller for applying the DIP algorithm to stabilize the temperature. I chose it because it is very simple to program using the Arduino IDE, in addition to the many built-in folders.
The temperature is read by the thermocouple available in the solder, the read voltage value is amplified up to about 120 times using an op-amp electric heater. This result is connected to the ADC0 pin of the microcontroller that can convert the voltage into a range of values from 0 to 1023.
With the set temperature knob, I use a variable resistor. It is connected to the ADC1 pin of Atmega8. When turning the variable resistance, the voltage variation in the range 0 to 5V is converted to 0-1023 by the microcontroller ADC.