nt115 jbc handle for ksger t12 with cfw by DavidAlfa

[Grucha9898]

Hello everyone, Does someone connect nt115 to ksger t12? I want cheap and good micro station to reparing iphones etc. I'm trying to connect nt 115 to this station with cfw by DavidAlfa, i changed heater resistance in options to 3,5ohms, and powerup board 9v from power supply, but it doesnt work, station cant see ntc from c115 tip. Did someone that? Is it work? Can someone describe me that? Thanks for help and sorry for my crappy english

[DavidAlfa]

Be very careful! The controller has no way to correctly control the tip until you calibrate it, it's very easy to burn it!
The NT115 is only rated for 14W!
For now, go into IRON options and set the power limit to 5W to reduce the risk of damage from uncontrolled temperature regulation.

That picture is not for the standard wiring, it won't work unless you modify the controller board.
By default, the sensor is joined to the heater. You need to cut this trace, and feed the sensor using a different pin.
Post pictures of your board.

Also, 9V is very low, the default voltage protection is set to 11V for a reason: The mosfet won't switch on correctly at such low voltage and might overheat.
You can lower it down to 9V at your own risk, but 8.99V will trigger the protection.
You can use 9.5V for testing purposes, and adjust the LVP setting. But I recommend using 12V.
As long as the heater resistance and power rating are correctly set in the options (15W), it should be safe, as the controller regulates the maximum PWM duty based on the power supply voltage reading and heater resistance value.

If you plan to power it using batteries: Use 3S(3-in-series) batteries, you'll get 11.1V(Fully discharged) - 12.6V(Fully charged).

Once you modify the board correcty, enter the calibration menu.
Now insert a completely cold tip. Only insert it in while in this screen, power is disabled here.
If the tip is warm, even slightly, remove it, wait 10 minutes and try again.
Avoid touching the tip with your fingers, or you might warm it up slightly, this will affect the calibration accuracy.

Now enter the SETTINGS menu (I repeat: Ensure the tip is cold!)

Click on "Zero set".
You'll see "Sampling". This is amplifier offset error calibration. The value should be stable, maybe moving 1..3 up and down.
If the value is slowly falling, it means the tip slighly warm, wait until it's stable.
You have a 5 minute inactivity timeout, move the encoder up and down from time to time while you wait.

When the value is stable, click again, you'll see "Captured".
Click on "Save" to store this value now, so you don't have to repeat this step if something fails.

Enter the SETTINGS menu again, you'll see that "Zero set" now has the value you saved before.
Take the temperature probe and attach it to the NT115 tip.
Now click on "Cal 250ºC" and adjust the value until you get 250ºC in your probe. (It's is applied in real time).
Typically you'll go in small steps, waiting few seconds for the tip to heat up.
Once you got 250ºC, click again, and repeat with the 400ºC step.

Having the 5W power limit should make it easier to control, but have your eyes open, if you see the temperature rising very fast, quickly reduce this value to avoid burning the tip.
You might want to reduce it from the beginning, just for safety. You can always increase the value, but you can't fix a burned JBC tip!

Once both calibrations are done, click on "Save", and the station should be ready for use.
Ensure everything works, then you can rise the power all the way up to the nominal value (15W).

[Grucha9898]

Thanks for help, i burned my first tip so i will be carefull with another. I will use it under microscope, so i want a toroidal transformer, which one fit to case of station (i have small one), so do you recommend 10v minimum? Even if original jbc station use 9v? How should i proper my board? Thanks for fast answer
I have 3 ksger station, if i want next station for t210 should i modify pcb too?

[DavidAlfa]

Sure, 9...10V, not a big difference.
Both voltages can exceed the power of the tip by almost twice its rated power!
As I said, as long as the power is properly limited, it shouldn't be a problem.

Where did you get that wiring from? It seems for the original JBC stations, that won't work on ksgers and such.

Please attach the resistance readings between the tip connections, as shown in the attached picture.
The NT115 connection seems to be the same as the C245, but I haven't tested it.

These cartridges can heat up extremely fast, it can only take 15 seconds to destroy the tip.
- Never connect the tip unless everything is properly configured.
- Setup the power limit to the minimum, adjust the heater resistance half than real, so it limits the power even more.
- Keep the power supply switch close to you, so you can turn it off quickly.
- Put the tip in the wet sponge, power on the unit for 5-10 seconds, check if the temperature measures something.
- If you hear crackling noises, you know the tip is getting power... it won't heat so wildly with the wet sponge, you'll have more reaction time.

[Grucha9898]

I get the wiring from eev blog, but i dont remmember the topic.
I think i need new tip because when i put tip to the handle its short circuit, if i connect everything correctly, i will back to this topic when i get new one.
I appreciate your help, i will give info if everything will work correctly. Can someone recommend brands for jbc tips? When Everything will work correctly i get original tips.
Thanks DavidAlfa

[DavidAlfa]

First, post the resistance measures. You might be wiring it wrong.

I can't recommend any JBC clone.
My last ones died after few hours while using them at 350ºC, they didn't had time to blacken.
With the previous ones, the tips fell down after 1-2 hours of use.
All of them had terrible thermal performance. They're absolute crap.
If someone tells you they're good, it's because they have never used genuine JBC tips.
It's like night and day.

[Grucha9898]

I mark wires from my handle on this tip. Maybe i'm stupid but i dont get that how to connect it one time i cant heat up the tip but sensor work, other time tip heat up but i dont get temp form tip. Thanks for patience David

I connect it like on picture and of course cut line near r11, when I put tip to half of handle i got temp sensor read, when i put tip to the end off handle(like it should be) i get short circut

[DavidAlfa]

So it seems the heater and the thermocouple connections are reversed respect to C245.
Try this.

[Grucha9898]

So i connected like A->Green, B->Red and C->Blue(White wire from board in my case), if i change blue with red wires tip heat up to max. Maybe the tip is burned out now and its get short circuit. If my tip is still good, its must be another way to connect it. I dont want buy geniue jbc tip if i cant be sure it will work.

[DavidAlfa]

The sensor will show like a short circuit, that's normal.
The heater is clearly the pins A-C (3.2ohms)
I wonder if the TC is connected backwards l, so it supplies negative voltage?
Carefully heat the tip with a lighter while you measure the voltage in pins B-C.
You should set the voltmeter in the smallest scale, which lets you measure 2-4mv with best accuracy.
The voltage should rise as you heat the tip, but it might go positive or negative...

[Grucha9898]

So B is minus and C is plus, like on photo

[DavidAlfa]

What does it read in A(-) --- B(+) configuration?

[Grucha9898]

That. So can it work? 🤔

[Grucha9898]

Bump

[DavidAlfa]

Edit: So this seems to be the pinout...

[Grucha9898]

Thanks for help, i will try maybe tomorrow. You helped me a lot!

[DavidAlfa]

You must understand this, anything touching the power supply negative will be seen as -24V by the earth.
So ensure nothing exposed outside the station is connected to that.

Maybe someone here could advice better.