The Chinese SJK Induction Heater and The VapCap

[Hackerman]

Let's see if I can trace the pins on that mysterious K12 14 pin IC. I have done numerous searches to try to identify it and that logo is non-existent. If nothing else, I can log the data pin and see what it sends on startup. That should give us something.

Not that it really matters what chip it is but..... now it has my curiosity up and so I'll give it a shot.

This is all done utilizing the pics I loaded earlier in this thread so anyone can chime in on my mistakes any time they see one.

Pin 1 is no connection
Pin 2 is connected to 2 transistors and then to the fan ground
Pin 3 is no connection
Pin 4 is connected to a transistor and then to the signal relay that controls the induction heater circuit.
Pin 5 is no connection
Pin 6 is no connection
Pin 7 is connected to the LED pin 2 of 3
Pin 8 Ground
Pin 9 Vs
Pin 10 is connected to pin 5 on the 8 pin smd chip which is (Q Output)
Pin 11 is No Connection
Pin 12 is connected to the LED pin 1 of 3
Pin 13 is connected to the LED pin 3 of 3
Pin 14 is no connection

So, in short...
Pin 10 is the input pin reading data from the 8 pin smd ic.
Pins 7, 12 and 13 control the LED
Pin 2 controls the fan
Pin 4 controls the induction heater circuit.

There it is as best I see it.

 

[stardustsailor]

Let's see if I can trace the pins on that mysterious K12 14 pin IC. I have done numerous searches to try to identify it and that logo is non-existent. If nothing else, I can log the data pin and see what it sends on startup. That should give us something.

Not that it really matters what chip it is but..... now it has my curiosity up and so I'll give it a shot.

This is all done utilizing the pics I loaded earlier in this thread so anyone can chime in on my mistakes any time they see one.

Pin 1 Ground
Pin 2 Vs
Pin 3 is connected to pin 5 on the 8 pin smd chip which is (Q Output)
Pin 4 is No Connection
Pin 5 is connected to the LED pin 1 of 3
Pin 6 is connected to the LED pin 3 of 3
Pin 7 is no connection
Pin 8 is no connection
Pin 9 is connected to 2 transistors and then to the fan ground
Pin 10 is no connection
Pin 11 is connected to a transistor and then to the signal relay that controls the induction heater circuit.
Pin 12 is no connection
Pin 13 is no connection
Pin 14 is connected to the LED pin 2 of 3

So, in short...
Pin 3 is the input pin reading data from the 8 pin smd ic.
Pins 5, 6 and 14 control the LED
Pin 9 controls the fan
Pin 11 controls the induction heater circuit.

There it is as best I see it.

Well ,it seems that the mysterious IC has to be a quad single pole /single throw CMOS analog switch IC .
Something like the TS12A4451x series from T.I.
Though they seem to have different pin out .

So ,once more the pin out of that mysterious IC :

Pin 1 Ground

Pin 2 Vs

Pin 3 IN #1 ( signal from the 355G OUT )

Pin 4 NC ( but may as well be a COM or IN )

Pin 5 OUT #1

Pin 6 OUT #2

Pin 7 NC ( but may as well be a COM or IN )
Pin 8 NC ( but may as well be a COM or IN )

Pin 9 OUT #3 ( to a Darlington pair driving the fan )

Pin 10 NC ( but may as well be a COM or IN )

Pin 11 OUT #4

Pin 12 NC ( but may as well be a COM or IN )
Pin 13 NC ( but may as well be a COM or IN )

Pin 14 COM (provides the GND to the bicolor LED

But while ther are 4x active outputs ( pins 5,6,9 & 11 ) ,
there's only one active input (pin 3)

3 inputs are missing .

Thus PIn3 input has to be shorted with three more pins
( out of these : 4 ,7,8,10,12,13 ).
If you can not spot any traces on the pcb shorting pin 3 with three other pins ,
maybe they are hardwired somewhere under the IC socket ,or there are indeed traces under it .

 

[Hackerman]

Take a look at these pics. I don't have photo edit on this computer so we'll have to speak it. LOL

You can see pin 3 comes off the 14 pin ic directly to pin 5 of the smd chip and the only other connection on that trace is a resistor going to the output on the voltage regulator. ?? Does seem odd that 1 input would control 3 outputs. But, I sure don't see anything. I'll pull the chip and look under it.

EDIT: I just pulled the chip and there are definitely no jumpers or traces under there.

 

[stardustsailor]

Actually what you call as pin #3 is pin #10 .
Pin #1 is located besides the dot on the IC .

Yes the resistor is there to bring up the signal to HIGH.
When the 355 G out is HIGH then the signal becomes LOW ( brought to ground ) .
That means that all the outputs of the analog switch IC ( KW12 ) are normally closed.

355G OUT - KW12 IN - KW12 4x OUT
-------------------------------
LOW - HIGH - LOW
HIGH -LOW -HIGH

Or it can be even the 2xNC & 2xNO kind

355G OUT - KW12 IN - KW12 OUT
-------------------------------
LOW - HIGH - 2x LOW & 2x HIGH
HIGH -LOW -2x HIGH & 2x LOW

 

[Ricardo]

You're all doing very well https://media.tenor.co/images/fccd56e3d88c904b53cdb80b3e2c467b/raw

 

[Hackerman]

@stardustsailor Oops, I forgot to tell you that I 'mirrored" the other picture so it would match the layout of the other picture. On the component side of the board Pin 1 is easily identified by the dot, like you said. On the solder side, the pin 1 is the square pad.

Sorry, I should have mentioned that.

EDIT:

Wait a minute, something is fucked up here.

The square pad is always pin 1, right?

And, the socket is properly oriented with the 'half circle' at the square pad.

However, the chip is inserted the wrong way. I am simply assuming that the socket (and the square pad) was put on backwards and that the chip is correct.

So, now, we do have pin 8 on the square pad.

I'll redo the pinout. Sorry about that.

OK, I think I got it right this time. Thanks for pointing that out. I also went back and edited my previous pinout post.

Pin 1 is no connection
Pin 2 is connected to 2 transistors and then to the fan ground
Pin 3 is no connection
Pin 4 is connected to a transistor and then to the signal relay that controls the induction heater circuit.
Pin 5 is no connection
Pin 6 is no connection
Pin 7 is connected to the LED pin 2 of 3
Pin 8 Ground
Pin 9 Vs
Pin 10 is connected to pin 5 on the 8 pin smd chip which is (Q Output)
Pin 11 is No Connection
Pin 12 is connected to the LED pin 1 of 3
Pin 13 is connected to the LED pin 3 of 3
Pin 14 is no connection


So, in short...
Pin 10 is the input pin reading data from the 8 pin smd ic.
Pins 7, 12 and 13 control the LED
Pin 2 controls the fan
Pin 4 controls the induction heater circuit.

 

[stardustsailor]

I do not have much time allowing to get me involved further with this circuit.

But some quick notes :

- Pin #7 is the voltage supply pin of the KW12.
There are two bypassing caps ( PP film and an electolytic one ) connected to that pin.
It also supplies voltage to the LED (middle LED pin ) The LED has to be a common anode one .

-Pin #9 is an OUTPUT signalling (via a transistor ) the relay next to the 355G IC .

_ the two transistors that control the fan most probably are not a Darlington pair ( NPN - NPN )
but a Sziklai pair (NPN with PNP )

-There are some more ICs on the pcb .Any info about them ?

- How the LED behaves ? ( i dont have such IH device ) ?

 

[JigMelon]

@Ricardo Yea, it's definitely not a hassle to just pull it out and reinsert. That being said, I've made my own hands-free mod, similar to what @DDave has on his site, and if I have to pull out the vap and put it back in before putting it on my glass, there's no point of it being hands-free in the first place.

In regard to the cap clicking for some before it gets to the cooldown cycle, keep in mind that all vapcaps are slightly different (as mentioned above). More importantly, the depth in which you place the vapcap within the IH will drastically affect the time needed to click, as well as the length of heat retention and how much the stem/bowl gets heated. Knowing this, you should be adjusting the depth of the vapcap based on the flower and the size you have the bowl set to. Additionally, you may want to adjust to your ideal temp retention length, similar to choosing between 1/2/4 flame torches.

Also, I have two versions of the hands-free mod; 1 is without silicon and is all glass, and the other uses silicon (similar in concept to @DDave's version) along with an O-ring to adjust the depth more precisely. I'll upload pics tomorrow to show what I mean. Earlier today I was able to get really consistent vaping with the O-ring adjustment capability. @DDave you'll definitely want to consider adjusting your mod or making another version after seeing what I have setup; you might even be able to get a higher profit return since it involves additional parts.

 

[LesPlenty]

I went low tech and ended up with a 7.5mm thick piece of cork in the top hat. I just hold my M18 xl or Ed`s TNT TI Cigar against it and they both heat up to at least 1 click before the IH hits the cool/safety zone(one cap seems to have a longer time before the second click happens)
I am pretty sure you can adjust the depth of insertion with the @DDave mod as it has a silicon sleeve to hold it where you put it.

 

[DDave]

@DDave you'll definitely want to consider adjusting your mod or making another version after seeing what I have setup;

I'm always game for improvements and other ideas...

Do you have any pics you can share?

I am pretty sure you can adjust the depth of insertion with the @DDave mod as it has a silicon sleeve to hold it where you put it.

Spot on!

 

[Ricardo]

More importantly, the depth in which you place the vapcap within the IH will drastically affect the time needed to click, as well as the length of heat retention and how much the stem/bowl gets heated

I went low tech and ended up with a 7.5mm thick piece of cork in the top hat.

First it's 4mm, now it's 7.5! Do you think I'm made of cork man?
Seriously though, I have all my tips reduced to half or minimum (1 third) chamber capacity. The IH is working fine but if there's a risk of overheating I guess the sooner the Vapcap clicks, the better.

 

[LesPlenty]

I kept experimenting to see how far out I could get the tip so the rest of my Vapcap doesn`t get so bloody hot. I went as thick as 10mm, but that was clicking way too soon, I think I have settled on the 7.5mm, for me anyhow, although I don`t think the missus heard me as she is still giving me heaps of champagne corks.
FYI, I always have max chamber sized loads.

 

[JigMelon]

@LesPlenty Absolutely! I didn't mean to suggest otherwise; sorry for not being clear. What I meant is that the O-ring being on the stem allows another option for adjustment, and is also a bit easier to adjust on the fly between rips within the same pack.

@DDave I don't have any pics right now; still in the office. I'll have pics up in 3-5 hours, and I'll mention you when I put them up.

I'd actually say the ideal setup would have both adjustable spots; one for adjusting the depth of the piece in the IH (like yours) and one for adjusting the depth of the vapcap in that piece (O-ring does that; it will make sense later with pic). I have a glass open-top dome that fits in the IH's detached cup with almost a friction fit, and the insertion distance of the vapcap is perfect. However, the thickness of the glass surrounding the vapcap was either acting as a thermal insulator or was interfering with the magnetic field (not sure if that's possible; not my area of expertise...), and I had much better results when there was no such layer between the vap cap and the coil. I'll be sure to get pictures of this too.

Edit: Rather than retyping explanations for the pictures, I'm just gonna make a video in addition to the pictures.

 

[JigMelon]

Alright, I made a quick video. Making a new post for the alerts; hope mods don't mind.

https://streamable.com/x3fdn

This video is just a quick explanation of what I was saying in the above post. Here are pictures from the first iteration, which is when I noticed that the glass was heating:

https://www.instagram.com/p/Bl3xtz4A4w_/

@DDave The two suggestions I have for your version is to find a way to get the cap exposed and not surrounded by glass, and to add a way to adjust the depth more easily/quickly. I hope the video helps explain what I mean in regard to those points.

Also, sorry for the grainy video and the peaking mic; didn't want to spend an hour setting up a 4 minute video.

Edit: The wands that I mentioned can be found in @Hackerman's post here:

http://fuckcombustion.com/threads/t...ater-and-the-vapcap.29630/page-3#post-1281359

Edit 2: Important note that I didn't mention in the video... The original DynaVap stem is there so you can see how the same concept could work with a default setup, assuming you could find the right sized O-ring.

Edit 3: @DDave Maybe a good solution to look into would be a 3d-printed piece that replaces the IH's plastic cup. This way all the same features could be implemented with a single piece (other than the O-ring) and without the silicon (other than the O-ring...).

 

[Hackerman]

-There are some more ICs on the pcb .Any info about them ?

- How the LED behaves ? ( i dont have such IH device ) ?

The chip in the solder side of the board is a THX208. It's the PWM controller that switches the ac/dc power conversion. http://www.datasheetcafe.com/thx208-datasheet-pdf-pwm-controller-thx/

The LED is green and red. Green with power on. Red when heating. Flashing green each cycle and flashing red for overheat.

The 4 pin chip on the component side says EL817 An isolator. I didn't know what this was and I was reading about it. Very cool concept for isolation.

https://www.datasheets360.com/pdf/-7167220994555226357?query=el817&pqid=98424508

 

[stardustsailor]

The chip in the solder side of the board is a THX208. It's the PWM controller that switches the ac/dc power conversion. http://www.datasheetcafe.com/thx208-datasheet-pdf-pwm-controller-thx/

The LED is green and red. Green with power on. Red when heating. Flashing green each cycle and flashing red for overheat.

The 4 pin chip on the component side says EL817 An isolator. I didn't know what this was and I was reading about it. Very cool concept for isolation.

https://www.datasheets360.com/pdf/-7167220994555226357?query=el817&pqid=98424508

EL817 is a photocoupler.
Photocouplers are used to send /receive signals between two separate circuits that
must not have any galvanic connection (like sharing a COMmon ground )

 

[LesPlenty]

@JigMelon , I believe the @DDave solution is made from existing parts he already has on hand, that is why it is simple and cheap. To roast your load a bit more it is much easier to just leave the Vapcap in a little longer rather than adjusting O-rings etc. I also left a few loads and the cap in the IH when trying tighter fitting glass options, funny at the time thinking, I am sure I heard the right click. That is part of the fun with this, different ways to use, bit like the Vapcap.

 

[Hackerman]

But some quick notes :

- Pin #7 is the voltage supply pin of the KW12.
There are two bypassing caps ( PP film and an electolytic one ) connected to that pin.
It also supplies voltage to the LED (middle LED pin ) The LED has to be a common anode one .

-Pin #9 is an OUTPUT signalling (via a transistor ) the relay next to the 355G IC .

_ the two transistors that control the fan most probably are not a Darlington pair ( NPN - NPN )
but a Sziklai pair (NPN with PNP )

Thanks for that. I missed that but it is clear, now.

 

[JigMelon]

Got another iteration:

https://streamable.com/5r6rz

This one just sits on that globe piece I showed in the other video. Not as easily adjusted, but was definitely easier to use. If someone were to make a custom cup for the IH like I mentioned above, I think having a loose-fitting stopper solution like this would be the best bet for the second (and possibly adjustable) piece.

@LesPlenty Well put; those are great points and I definitely agree! So much experimentation is before us!

 

[Ricardo]

Farewell Technics SLJ American (Professional Dental Quality) Induction Heater.
Shipped all the way from China to my little life for less than $50, I thought you were wonderful but, sadly, it was too good to be true
Now, we just go through the motions but the spark isn't there, the fire has gone - we no longer click
So, I guess I'll go back to my old flame and you, you will probably end up in that box full of scart leads and old modems; coaxial cables and old cellphones. (And VHF signal transmitter & receiver. Loads of chargers with different voltages and different sized plugs) .
It was beautiful while it lasted.
It was too beautiful to last.

 

[Hackerman]

Did your heater quit working?

If so, check this.... even though no fan is running and the LED is not blinking, place something metal in the hole and see if it heats up.

Does the green LED come on when you turn on the power switch?

 

[Ricardo]

Yeah @Hackerman but it's 2.30am and I'm wasted. Will investigate tomorrow

 

[Hackerman]

Cool. Sleep tight.

 

[LesPlenty]

Farewell Technics SLJ American (Professional Dental Quality) Induction Heater.

Were you using it upside down again?
Well it did sound like you got a second hand/refurbished unit to start with, get onto the seller and get them to send you another one, most Chinese sellers with over 98% positive feedback on ebay will look after you, they know we ae quality control and usually act accordingly.

 

[Ricardo]

get onto the seller and get them to send you another one, most Chinese sellers with over 98% positive feedback on ebay will look after you, they know we ae quality control and usually act accordingly.

You reckon? How do I explain my usage?
EDIT : @Hackerman The only metal I'm really interested in heating is Ti and SS Vapcaps but in the interests of science I've just inserted a steel knife (kitchen, not dental standard) and the thing got scorching hot in maybe 2 IH clicks - smoke wisped out of the "top hat".... the Cork insert beginning to burn..... Then I tried the Vapcaps again (empty - I can't wake n' and vake today) and yes, they clicked but almost two full IH cycles from cold - we are clearly abusing these units.
I rode it pretty hard last night, I think it just overloaded - it definitely didn't work, I had to switch to my lighters.
@LesPlenty, I won't be looking for a refund mate. I know they would probably send me a replacement but it's just not cricket, is it? If these things were designed for anything it was to heat razor thin dental knives in like, a second, maybe a couple of times a day.
We'll see how she goes later on - right now it's Fox Footy - Richmond v. Geelong!