JBC T245 pinout

[kuzm1nsk1]

Hi, I'm planning to design a controller for JBC T245 handle (C245 cartridges) but can't figure the right pinout for the cartridge. I have come across two different pinouts for the cartridge and don't know which one is the right one because I haven't purchased it jet. One picture shows cartridge measured with Fluke instrument and it's clearly different pinout from the picture that has been posted on EEVBLOG by a johnmx who reversed engineered the whole JBC station. Then I came across this post: https://www.eevblog.com/forum/projects/jbc-handle-cartridge-data/ and someone said that the Fluke measured one is the correct one. Do you have any experience with JBC cartridges so you could confirm one pinout over the other.

[thm_w]

Welcome, we have lots of threads discussing T245, please read through them.
I would trust the pinouts from this site, in the post you linked: http://adgd.ru/2021/01/04/jbc-soldering-cartridges-pinouts/

The reality is either way will work when implemented, JBC seems to run the current through the thermocouple: https://www.eevblog.com/forum/projects/yet-another-controller-for-jbc-t210t245/msg3102782/#msg3102782

[DavidAlfa]

This pinout is correct

[kuzm1nsk1]

If I'm not mistaken, Weller, Hakko and probably some other brands also have this type of cartridges with 3 pins. Is there a reason why they don't add a fourth pin to make life easier?

[thm_w]

If I'm not mistaken, Weller, Hakko and probably some other brands also have this type of cartridges with 3 pins. Is there a reason why they don't add a fourth pin to make life easier?

- More expensive to manufacture the tip
- More wires and contacts in the handle, means larger handle and thicker cable

You've seen the schematic, JBC does not seem to care about complexity at all.
If they logically designed their tips, you could support all of their tips with a micro, a few FETs and an ADC. But for whatever reason everything is all flipped around.