Homemade Soldering Station 2 (AVR)

Hello again,in this section we will make a professional soldering station

Original idea was from here

Homemade_Soldering_Station_2_AVR_18

the circuit is based on atmega8 from Atmel

The main idea is to observe the temperature of the soldering iron through a k type thermocouple and in proportion ,control the supply to the soldering iron.It is based on the p.i.d controller for a better and more accurate results.The circuit is power from 9-15 volts. Thermocouple is connected to MAX 6675. All compontes are very easy to find.

On each Cycle:

Error = SetPoint – Tip

Total_Error = Total_Error + Error

P = Kp * Error Or P = Kp * Error * Tip

I = Ki * Total_Error

D = Kd * ( Error – Previous_Error )

PID_out = P + I + D

PID_out is limited in range of -500 to +500

PID_out = PID_out + 500

And now we power the soldering Iron for PID_out milliseconds

Previous_Error = Error

 

Part list

R1 Resistor 470 Ohm 1/4 Watt 5% Carbon Film
R2 Resistor 470 Ohm 1/4 Watt 5% Carbon Film [
R3 Resistor 1 KOhm 1/4 Watt 5% Carbon Film
R4 Resistor 1 KOhm 1/4 Watt 5% Carbon Film
R5 Potentiometer 1 KOhm Linear Rotary 1/2W
R6 Potentiometer 1 KOhm Linear Rotary 1/2W
R7 Potentiometer 1 KOhm Linear Rotary 1/2W
R8 Potentiometer 1 KOhm Linear Rotary 1/2W
R9 Potentiometer 1 KOhm Linear Rotary 1/2W
R10 Potentiometer 1 KOhm Linear Rotary 1/2W

C1 Electrolytic Capacitor 470 uF 25 Volts
C4 Electrolytic Capacitor 220 uF 25 Volts
C3 Ceramic Capacitor 0.1 uF 50 Volts
C5 Ceramic Capacitor 0.1 uF 50 Volts
C2 Ceramic Capacitor 0.1 uF 50 Volts
C6 Ceramic Capacitor 0.1 uF 50 Volts

D1 1N4004

T1 2N3904 NPN

IC1 7805
IC2 ATmega8 Microcontroller
IC3 MAX 6675 Cold-junction compensated K-Thermocouple to digital converter (0°C to +1024°C) [Cold-junction compensated K-Thermocouple to digital converter (0°C to +1024°C)]

LCD 16×2 Character LCD w/ HD44780U1 controller

R1 Resistor 470 Ohm 1/4 Watt 5% Carbon Film
R2 Resistor 470 Ohm 1/4 Watt 5% Carbon Film

pot. 4.7k

T1 2N3904 NPN

IC1 MOC3021 Random Phase Optoisolator TRIAC Driver Output [Random Phase Optoisolator TRIAC Driver Output ]

Lfuse = E4h
Hfuse = D9h

Pontesiometer R5 varies the Kd factor from 0.00 to 100.00

Pontesiometer R6 varies the Ki factor from 0.00 to 100.00

Pontesiometer R7 varies the Kp factor from 0.00 to 100.00

Pontesiometer R8 varies the max temperature from 0 degrees C to 512 degrees C

Pontesiometer R9 varies the safe time from 0sec to 900sec

Hex file here:

Homemade_Soldering_Station_2_AVR_4

pcb

triac pcb

Eagle files

here is the pcd

pcb

start soldering the smd IC to the bottom side

smd

and after that all the other components

compontents

 

here is the small pcb with the optocoupler and the triac

bt138

 

Lets continue with the soldering iron. It is a cheap soldering from ebay for around 5 bucks.I tried to place the thermocouple as closer as i could to the tip ,so that the measured temperature to be as accurate as it could be.

soldering iron

 

IMG_0720 (Custom)

IMG_0721 (Custom)

IMG_0725 (Custom)

 

IMG_0726 (Custom)

IMG_0974 (Custom)

IMG_0730 (Custom)

Next, is the wooden box

IMG_0666 (Custom)

IMG_0669 (Custom)

IMG_0671 (Custom)

 

IMG_0670 (Custom)

IMG_0674 (Custom)

IMG_0668 (Custom)

IMG_0672 (Custom)

IMG_0680 (Custom)

IMG_0682 (Custom)

IMG_0685 (Custom)

IMG_0687 (Custom)

IMG_0688 (Custom)

IMG_0689 (Custom)

IMG_0697 (Custom)

IMG_0738 (Custom)

 

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