Originally Posted by deswong
Could you please post your diagram on how you put this together?
I have a soldering station that is playing up and I have been curious to see if I can just get a digital temperature controller and just use that to fix this unit?
Mine is quite old and I have tips and parts for the handle - just the actual board/controller has failed and will not shut off the power to the heater element.
Attached is a circuit diagram and a copy of the manual for the controller.
I'm not great at putting together circuit diagrams so please forgive me if it doesn't follow normal schematic rules.
The circuit is basically pretty simple.
Power comes in through the plug and goes to terminals 1 and 2 of the controller. Earth is connected to Chassis A fuse and mains switch are put inline with the active.
I put a power LED on the mains that I had lying around off an old charger but this is optional. I don't know the construction of the LED unit. An LED on its own would blow so it must have a small circuit in the unit (resistance).
The 24v transformer also came off the old charger I had and it is connected to the mains.
The soldering handle cord has 5 wires coming through the 5 pin plug. Black and yellow are the heater, Blue and red are the temperature sensor (Thermistor) and the green is earth connected to the body of the iron.
Pins 13 and 14 on the controller are the relay connection. So the heater black wire is connected to the 24v side of the transformer. The yellow heater wire inside the box is connected to pin 13 of the controller. Then from pin 14 the yellow wire goes through a switch and to the other side of the 24v.
The thermistor wires are connected to pins 9 and 10 of the controller which is the sensor input. If the sensor in the soldering iron was a k-type thermocouple then that is all that would be required. Unfortunately the thermocouples in the HAKKO irons are a themistor so it needs a resistance across pins 8 and 9 so that the controller can correctly sense the temperature. A 10k ohm variable resistor is connected and this resistance needs to be adjusted to calibrate the temperature correctly.
To calibrate the temperature I placed a k-type thermocouple on the tip of the iron and connected it to my multimeter. I then adjusted the zero offset in the meter menu's and the resistance to get the temperatures correct. There re other ways to get the temperature calibrated but this worked for me.
It is important to set the controller to PID control to get precise temperature control as the on/off control method is very rough. Once I had set up the parameters in the controller I found it would heat up to temperature within 60-90 seconds and controlled to within 1-2 degrees of the setpoint. If you end up getting the same type of controller (Model N2006P) I can post the settings for you. Just let me know
Down the track I may put a second controller in the box and add a second Soldering handle of 80-120W for big jobs. There's still plenty of room in the box and occasionally I would prefer a high power large tip iron.
Hope this helps