how does the JBC stand detect a iron and go into sleep mode?

Thread Starter

super7800

Joined Apr 3, 2019
28
hello all!

firstly look here: https://www.eevblog.com/forum/reviews/jbc-soldering-iron-stand-wiring/ to see the pinout of the stand. (or below).




the stand connects like this:



and the cartridge like this:


i'm looking to create my own "3+1" (2 iron, 1 tweezers) JBC station. i'm going to do that using a circuit which i've posted about here: https://forum.allaboutcircuits.com/threads/help-with-triac-selection-for-heater-control.163903/

my question is how does the JBC station detect that the iron is placed inside the holder? the cartridge has 3 pins. does it detect when the ground connects to the stand completing a circuit? does anyone have any recommendations for a circuit to detect this? my system uses 24vac, and the controller is 5v tolerant.

could i just use a 4N25 (or similar) opto isolator? here is something quick i whipped up to show what i mean:


any help/ recommendations are appreciated. i know that this is probably a simple problem, but it has me stumped on proper implementation. thanks!
 

Thread Starter

super7800

Joined Apr 3, 2019
28
@SLK001 Thanks for the input, but i don't think it is. if you look at the first image (the "schematic" of the stand), the blue and green wires which are used for sensing are connected directly to the metal of the spare tip keeper and soldering iron holder.

here is a picture of the stand in question:
 
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