JBC kartuş detayı, kontrol devresi ve detaylı açıklaması

[AxxAxx]

Nice to see you here. I really liked your project. But because the mcu you chose is not available locally and also for fun of it I will make my own.

About the contacts: While measuring resistance betweein contacts it seems like TC and the heater contacts are different than what you claim. But upon further thinking, it can be because of higher resistance of the meterial used for contacts (nessesarily dissimilar meterials maybe). What do you think? Is this the case?

Thanks, I see. making self is a big part of the fun!
Didn't know you could not source that MCU, I did a quick search, is this not availible in turkey ? https://tr.rsdelivers.com/product/s...onics-stm32-nucleo-32-development-mcu/1962534
Ok its more than just the MCU, but it seems availible?

Exactly which resistance measurement did you find differ from the internal component layout i suggested?
I'm interested in getting this right once and for all, there are so many different explanations online..

 

[AxxAxx]

It is great to see you here, writing in english not problem moreover we can translate the any post you want for you.

You explained very well why there is different wiring schemes, do you have any information about which one(s) are used to control the system in original design? I believe using TC1 is better since it has more voltage coefficient and due to the placement I believe the delay will be much smaller.

With your nomenclature the outer shell which we are actually using for soldering job is green, and in your design it is not connected to anywhere, but voltage level with respect to your ground is limited using diodes. What type of a power supply are you using? Is it connected to PE in ground side? I think voltage of the green section with respect to the earth should be somehow controlled, and depending on the power supply used, gnd can have voltage wrt to the earth, hence the green side can. Am i missing something or it is not much important for that type of a soldering iron?

Thank you

Thanks!

https://www.eevblog.com/forum/testg...ete-schematic-analysis/msg2514996/#msg2514996
In this post there is a PDF of a reverse engineered JBC CD-2BC. There you can see how the original connects to the cartridge.
This schematic seem to correlate to the JBC-DDE I have taken apart.

In my schematic GREEN is connected as an input to the OP-amp. The grounding "issue" is a big question. There is also a long discussion about this on the EEVBlog Forum. This topic is not handled very well in todays design, but I intend to look into and hopefully solve this in the best way possible in a coming hw design. At the moment I am not sure about the best solution though. I personally use a SMPS with grounded negative.

 

[Sercan]

@AxxAxx, as I mentioned in our chat messages, I've taken pictures of my JBC CP-2QF unit. This unit has two PCBs: one mounted on the backside and the other positioned behind the LCD on top. I haven't opened the cover of the second PCB.

However, the backside PCBs reveal the connections, offering insights into handling the pinouts. I hope this information is helpful.

Additionally, I will provide a translation of this message below.

---

Arkadaşlar aşağıdaki PCB resimleri benim JBC CP-2QF cihaza ait. LCD ekranın altındaki PCB'yi açmaya üşendim ama zaten MOSFET bağlantıları burada olduğu için çok yüksek ihtimalle tutamacın bütün kontrolü buradan yapılıyor. Diğer PCB'de sadece mikroişlemci filan olsa gerek.

 

[Sercan]

That's the second PCB from my unit.

Buda ikinci PCB.

 

[clc]

Thanks!

https://www.eevblog.com/forum/testg...ete-schematic-analysis/msg2514996/#msg2514996
In this post there is a PDF of a reverse engineered JBC CD-2BC. There you can see how the original connects to the cartridge.
This schematic seem to correlate to the JBC-DDE I have taken apart.

In my schematic GREEN is connected as an input to the OP-amp. The grounding "issue" is a big question. There is also a long discussion about this on the EEVBlog Forum. This topic is not handled very well in todays design, but I intend to look into and hopefully solve this in the best way possible in a coming hw design. At the moment I am not sure about the best solution though. I personally use a SMPS with grounded negative.

If your power supply is negative grounded actually voltage of green is limited at least. It is not a bad solution, have you faced any problem while using it? I will also check EEVBlog for grounding issue, i believe most of the diy projects ignore it. Schematic also seem correleate the photos shared by @Sercan , there is net names like I_leak, does it really measures the leakage current? I used that jbc stations only for short times, but using weller ones oftenly and I never see or heard an alert about leakage current. Do jbc stations have a alert on leakage current?

I will check the schematic detailed later, it seems really cost optimized for mass production, but i think design like yours is better.

For the mcu issue which @semih_s said, rsdelivers, digikey, mouser and all other global suppliers available for Turkey. However due to our a little problematic customs buying directly is not preferred(maybe if there is really small number of components it can be risked), we are using distrubutors for them. However, most of the people on the Turkey which works in diy projects like this doesnt want to use distrubutors, they want to buy from local suppliers(I am also not sure why). Local suppliers has very limited range of components and ST's G4 family has history of maybe 2-3 years I think, so they are not selling it. However I dont think MCU is critical for this project, any modern MCU can be used with maybe some tradeoffs.

 

[taydin]

Even for the pinout I claim (using my nomenclature) of RED, GREEN and BLUE terminal, you can:
Heat up the tip by applying a voltage over BLUE-GREEN.
Measure TC voltage over GREEN-RED.

I haven't seen any place where an arrangement other than this is depicted. And that's what I can confirm when I measure my c245 tip. When I measure between GREEN and BLUE in 4 wire mode with offset compensation, I get 2.778 Ω, which is probably the heating element. When I measure between GREEN and RED, I get 0.046 Ω, which is probably the thermocouple, because I'm measuring a voltage between GREEN and RED that changes with temperature. So this has to be the correct arrangment.

I have read your post on eevblog and your message here, and it's not clear to me whether you are agreeing with the above or not

 

[semih_s]

Thanks, I see. making self is a big part of the fun!
Didn't know you could not source that MCU, I did a quick search, is this not availible in turkey ? https://tr.rsdelivers.com/product/s...onics-stm32-nucleo-32-development-mcu/1962534
Ok its more than just the MCU, but it seems availible?

Exactly which resistance measurement did you find differ from the internal component layout i suggested?
I'm interested in getting this right once and for all, there are so many different explanations online..

At the time of my search i couldn't find that.

Resistance is measured higher between inner contact and middle contact, than the outer contact and middle contact. Assumed TC resistance is measured about 50 mOhms. It is about the differance between the inner to midle and outer to middle resistance. But actually this does not nesessarily mean that TC joint has a measurable resistance. It should be resistansce of the lead from joint to measurement point.

Looking at the grinded tips it is obvious that one side of the heater is connected to middle contact. But the other side of the contact is not, it might be connected to inner or outer.

This can be explained if we knew what each contact is made of.

If what i think is true; the contacts that are connected to heater are made of same meterial(middle and outer), seeback effect cancels (between the heater coil and contact meterials) and we won't see voltage betwen heater contacts. It is only nessesary to make one contact from defferent metal to get seeback effect, and it is the inner one and is higher resitance

Alternative description may be; what you described is true and the resistance of the inner contact meterial is -again- high and about 40 mOhm. If those thermocouples cancel each other as you described, this means the outer and middle contacts must be made out of same meterial and inner one different. And inner contact meterial is relatively high resistance.

I read your eevblog forum post again. You could take measurements from the grinded tip, so you could measure resistance from coil to contact leads. Then your measuments must be true. I was inpecting as I wrote this post, so I left my reasoning for my assumption here. I have no reason to belive you made some mistake, your measurements must be true.

 

[Ahmet]

If your power supply is negative grounded actually voltage of green is limited at least. It is not a bad solution, have you faced any problem while using it? I will also check EEVBlog for grounding issue, i believe most of the diy projects ignore it. Schematic also seem correleate the photos shared by @Sercan , there is net names like I_leak, does it really measures the leakage current? I used that jbc stations only for short times, but using weller ones oftenly and I never see or heard an alert about leakage current. Do jbc stations have a alert on leakage current?

I will check the schematic detailed later, it seems really cost optimized for mass production, but i think design like yours is better.

For the mcu issue which @semih_s said, rsdelivers, digikey, mouser and all other global suppliers available for Turkey. However due to our a little problematic customs buying directly is not preferred(maybe if there is really small number of components it can be risked), we are using distrubutors for them. However, most of the people on the Turkey which works in diy projects like this doesnt want to use distrubutors, they want to buy from local suppliers(I am also not sure why). Local suppliers has very limited range of components and ST's G4 family has history of maybe 2-3 years I think, so they are not selling it. However I dont think MCU is critical for this project, any modern MCU can be used with maybe some tradeoffs.

when we create the project with any mcu it will take a short time to re-create it for a completely different mcu avr, dsPIC, stm...
I love using the RP2040 but it's not very good for analog reading
for now we are in favor of the pcb we have and the AVR we are prone to "Atmega88<3"

 

[AxxAxx]

If your power supply is negative grounded actually voltage of green is limited at least. It is not a bad solution, have you faced any problem while using it? I will also check EEVBlog for grounding issue, i believe most of the diy projects ignore it. Schematic also seem correleate the photos shared by @Sercan , there is net names like I_leak, does it really measures the leakage current? I used that jbc stations only for short times, but using weller ones oftenly and I never see or heard an alert about leakage current. Do jbc stations have a alert on leakage current?

I will check the schematic detailed later, it seems really cost optimized for mass production, but i think design like yours is better.

For the mcu issue which @semih_s said, rsdelivers, digikey, mouser and all other global suppliers available for Turkey. However due to our a little problematic customs buying directly is not preferred(maybe if there is really small number of components it can be risked), we are using distrubutors for them. However, most of the people on the Turkey which works in diy projects like this doesnt want to use distrubutors, they want to buy from local suppliers(I am also not sure why). Local suppliers has very limited range of components and ST's G4 family has history of maybe 2-3 years I think, so they are not selling it. However I dont think MCU is critical for this project, any modern MCU can be used with maybe some tradeoffs.

I have not faced any problems with my soldering setup. But I think that if a user uses a floating SMPS there could be problems with not grounding the tip properly. Idealy the user should be able to use any type power source and have the possibility to ground the tip (Connect to Protective Earth).

Regarding I-leak, I have never seen any feedback to the user about this. But I guess JBC put the I_leak ther for a reason.. Don't know exactly why though..

OK, thanks for expalining the MCU sourcing issue, and indeed, any modern MCU will do the job.

 

[AxxAxx]

I haven't seen any place where an arrangement other than this is depicted. And that's what I can confirm when I measure my c245 tip. When I measure between GREEN and BLUE in 4 wire mode with offset compensation, I get 2.778 Ω, which is probably the heating element. When I measure between GREEN and RED, I get 0.046 Ω, which is probably the thermocouple, because I'm measuring a voltage between GREEN and RED that changes with temperature. So this has to be the correct arrangment.

I have read your post on eevblog and your message here, and it's not clear to me whether you are agreeing with the above or not

I agree that your measurements are correct. I get similar result.
But I think the conclusion that only the heater is between GREEN-BLUE and only the TC is between GREEN-RED like the figure below is wrong.

Instead I suggest this (below) configuration.
Your measurements fits this configuration as well,
GREEN-BLUE Resistance 2.778 Ohm - In fact you measure the heater and TC in series (TC resistance is close to zero).
GREEN-RED Voltage changes with temperature - Yes, now you are measuring the seeback voltage from TC1.

This is my suggestion, but as I said, i'm up for ideas that prove this wrong

 

[taydin]

But what is your motivation for using this alternate connection method? Did you run into issues that your method is resolving? As far as I can see, if you apply the heater current into BLUE and RED, you are basically passing more than 7 Amps through the thermocouple when the tip is cold and then you are passing PWM current through that same thermocople. Won't this have a negative impact on the temperature measurement?

And also, the BLUE/RED terminals (especially RED) were probably not intended to carry that much current.

 

[AxxAxx]

At the time of my search i couldn't find that.

Resistance is measured higher between inner contact and middle contact, than the outer contact and middle contact. Assumed TC resistance is measured about 50 mOhms. It is about the differance between the inner to midle and outer to middle resistance. But actually this does not nesessarily mean that TC joint has a measurable resistance. It should be resistansce of the lead from joint to measurement point.

Looking at the grinded tips it is obvious that one side of the heater is connected to middle contact. But the other side of the contact is not, it might be connected to inner or outer.

This can be explained if we knew what each contact is made of.

If what i think is true; the contacts that are connected to heater are made of same meterial(middle and outer), seeback effect cancels (between the heater coil and contact meterials) and we won't see voltage betwen heater contacts. It is only nessesary to make one contact from defferent metal to get seeback effect, and it is the inner one and is higher resitance

Alternative description may be; what you described is true and the resistance of the inner contact meterial is -again- high and about 40 mOhm. If those thermocouples cancel each other as you described, this means the outer and middle contacts must be made out of same meterial and inner one different. And inner contact meterial is relatively high resistance.

I read your eevblog forum post again. You could take measurements from the grinded tip, so you could measure resistance from coil to contact leads. Then your measuments must be true. I was inpecting as I wrote this post, so I left my reasoning for my assumption here. I have no reason to belive you made some mistake, your measurements must be true.

OK, got you.
Indeed, in theory the resistance GREEN-BLUE should be slightly larger than BLUE-RED..

How is it to measure a thermocouple resistance with a 4-wire resistance meter? Does the measurement get influeneced by the TC? I guess it depends on the internal current source of the resistance meter? I do not have access to any good instrument to measure milli-ohms at thye moment..

But as you say, measuring this small values also gets influenced by contact resistance and the length itself of the cartridge and material.. hmm....

 

[taydin]

How is it to measure a thermocouple resistance with a 4-wire resistance meter? Does the measurement get influeneced by the TC?

It makes a substantial difference (at least with respect to the value being measured). You need to use offset compensation. Not all meters support this, and the ones that do are usually bench type multimeters. I am using a Rigol DM3068. Without offset compensation turned on, I'm measuring the TC resistance as 63 mΩ. With offset compensation turned on, I'm measuring 45 mΩ

 

[taydin]

Burada bir genel özet geçelim Türkçe. @AxxAxx bu JBC uçlar için alternatif bir bağlantı şekli öneriyor. Muhtemelen de çalışıyordur, ben test etmedim, ama ben de bu alternatif bağlantı şeklini neden kullanmak istediğini, standart bağlantı şeklinde acaba bir sorun mu yaşadığını anlamaya çalışıyorum.

 

[Ahmet]

Burada bir genel özet geçelim Türkçe. @AxxAxx bu JBC uçlar için alternatif bir bağlantı şekli öneriyor. Muhtemelen de çalışıyordur, ben test etmedim, ama ben de bu alternatif bağlantı şeklini neden kullanmak istediğini, standart bağlantı şeklinde acaba bir sorun mu yaşadığını anlamaya çalışıyorum.

Abiyle birazcık sohbet ettik.
İsveçliymiş iyide elektronik biliyor, TC okurken yaşadığım büyük sorunlardan bahsettim güzel çözümler sundu.
Bunu deneyince yazarım sunduğu çözüm birşeye yarıyor mu?

Birisi bu adama söyledi mi acaba bak senin projenin üstünden sohbet dönüyor git bak ne oluyor diye yoksa tamamen kendi projesini takip ederken mi buldu burayı.

Sözümü tutarım herhalde 2023 son pazarında havya bitmiş olur )

 

[semih_s]

Burada bir genel özet geçelim Türkçe. @AxxAxx bu JBC uçlar için alternatif bir bağlantı şekli öneriyor. Muhtemelen de çalışıyordur, ben test etmedim, ama ben de bu alternatif bağlantı şeklini neden kullanmak istediğini, standart bağlantı şeklinde acaba bir sorun mu yaşadığını anlamaya çalışıyorum.

Bence doğru olabilir tespit etiği pinout. Uç malzemesinin direnci yüksek. dış kılıf uçtan uca 10mOhm civarı ölçülüyor. Eğer en iç kontak daha yüksek dirençli bir malzeme ise Isıtıcıyı taşlamadan aldığımız ölçümleri yanıltıyor. Taşladığında ısıtıcı direnç sargısının hangi kontağa bağlı olduğunu tespit edebilmiştir. Ucu taşlamadan dışardan aldığımız ölçümlerde 3 denklem ve 4 bilinmeyen çıkıyor ve bilinmeyenler için tek çözüm bulunamıyor. Yani uçtan kontaklara kadar olan dirençler işi karıştırıyor.

 

[ibrahimcelik]

Abiyle birazcık sohbet ettik.
İsveçliymiş iyide elektronik biliyor, TC okurken yaşadığım büyük sorunlardan bahsettim güzel çözümler sundu.
Bunu deneyince yazarım sunduğu çözüm birşeye yarıyor mu?

Birisi bu adama söyledi mi acaba bak senin projenin üstünden sohbet dönüyor git bak ne oluyor diye yoksa tamamen kendi projesini takip ederken mi buldu burayı.

Sözümü tutarım herhalde 2023 son pazarında havya bitmiş olur )

Kaldı 4 haftan Ahmet

 

[volta]

Havya ucu ortadan ikiye nasıl bölünüyor böyle, dremel ile olacak iş mi? Yoksa daha profesyonel birşey mi lazım?

 

[Ahmet]

Havya ucu ortadan ikiye nasıl bölünüyor böyle, dremel ile olacak iş mi? Yoksa daha profesyonel birşey mi lazım?

su jeti galiba

 

[Ahmet]

Kaldı 4 haftan Ahmet

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