House, design, renovation, decor. Courtyard and garden. With your own hands

Reading local reviews, I have already thought about buying a soldering iron with a T12 tip. I have long wanted something portable on the one hand, powerful enough on the other, and, of course, maintaining the temperature normally.
I have relatively many soldering irons purchased from different times and for different tasks:
There are quite ancient EPSN-40 and "Moskabel" 90W, a little newer EMP-100 (hatchet), a completely new Chinese TLW 500W. The latter two are particularly good at keeping the temperature (even when soldering copper pipes), but it's not very convenient to solder microcircuits with them :). An attempt to use the ZD-80 (pistol with a button) failed - neither power, nor normal temperature maintenance. Other "electronic" little things like Antex cs18 / xs25 are suitable only for very little things, and they have no built-in adjustment. About 15 years ago I used the den-on "ovsky ss-8200, but the stings there are very tiny, the temperature sensor is far away and the temperature gradient is huge - despite the declared 80W, the sting will not feel even a third.
As stationary option I have been using Lukey 868 for 10 years (this is almost 702, only a ceramic heater and some other little things). But there is no portability in it, you can't take it with you in your pocket or a small bag.
Because at the time of purchase, I was not yet sure "do I need it", the minimum budget option was taken with a K-sting and a handle that was as similar as possible to the usual Lukey soldering iron. It is possible that it does not seem very convenient to someone, but for me it is more important that the handles of both used soldering irons are familiar and equally in the hand.
Further review can be conditionally divided into two parts - "how to make a device out of spare parts" and an attempt to analyze "how this device and controller firmware work".
Unfortunately, the seller removed this particular SKU, so I can only provide a link to a picture of the product from the order log. However, there is no problem finding a similar product.

Part 1 - construction

Result:
1) The soldering iron works roughly as advertised and fits perfectly in jacket pockets.
2) Disposed of in the old trash and no longer lying around: a power supply, a piece of fiberglass from 40 years ago, a bottle with nitro enamel produced in 1987, a microswitch and a small piece of aluminum.

Of course, from the point of view economic feasibility it is much easier to buy a ready-made case. Let the materials were practically free, but “time is money”. It's just that the “make cheaper” task did not appear on my list of tasks at all.

Part 2 - notes on functioning

As some preliminary warning, I want to say:
1) Different controllers have slightly different circuitry. Even superficially identical boards may have slightly different components. Because I have only one of my specific devices, I can not guarantee the coincidence with others.
2) The controller firmware that I analyzed is not the only one available. It is common, but you may have a different firmware that functions in a different way.
3) I in no way claim to be a pioneer. Many points have already been covered by other reviewers.
4) There will be a lot of boring letters and not a single funny picture. If internal organization not interested - stop here.

Design overview

As you can easily see, all functioning is determined by the microcontroller. Why the Chinese put it exactly like this - I do not know, it is not very cheap (about $ 1, if you take several pieces) and end-to-end in terms of resources. In a typical Chinese firmware, literally a dozen bytes of program memory remain free. The firmware itself is written in C or something similar (the obvious tails of the library are visible there).

Controller firmware operation

There are several modes of operation:
1) Normal, normal temperature maintenance
2) Partial energy saving, temperature 200 degrees
3) Complete shutdown
4) Setting mode P10 (temperature setting step) and P4 (thermocouple op amp gain)
5) Alternative control mode

After starting, mode 1 works.
A short press of the button switches to mode 5. There you can turn the regulator to the left and go to mode 2 or to the right - increase the temperature by 10 degrees.
A long press switches to mode 4.

In previous reviews, there was a lot of controversy about how to properly install the vibration sensor. According to the firmware I have, I can say unequivocally - no difference. Departure to the partial power saving mode is performed when there is no changes the state of the vibration sensor, the absence of significant changes in the temperature of the tip and the absence of signals from the handle - all this within 3 minutes. A vibration sensor is closed or open - it does not matter at all, the firmware analyzes only changes in the state. The second part of the criterion is also interesting - if you are soldering, then the temperature of the tip will inevitably float. And if a deviation of more than 5 degrees from the specified one is recorded, there will be no exit to the power saving mode.
If the power saving mode lasts longer than the specified one, the soldering iron will turn off completely, the indicator will show zeros.
Exit from energy-saving modes - by vibration or by the control knob. There is no return from full to partial energy saving.

The MC maintains the temperature in one of the timer interrupts (there are two of them, the second deals with the display, etc. It is not clear why this was done - the interrupt interval and other settings were the same, it was quite possible to do with a single interrupt). The control cycle consists of 200 timer interrupts. At the 200th interrupt, the heating is necessarily turned off (- as much as 0.5% of the power!), A delay is performed, after which the voltage is measured from the thermocouple, the temperature sensor and the reference voltage from the TL431. Further, all this is converted into temperature according to formulas and coefficients (partially set in nvram).
Here I will allow myself a small digression. Why a thermal sensor in such a configuration is not entirely clear. When properly organized, it should give a temperature correction to the cold junction of the thermocouple. But in this design, it measures the temperature of the board, which has nothing to do with the required one. It either needs to be transferred into a pen, as close to the T12 cartridge as possible (and another question is where the thermocouple cold junction is located in the cartridge), or discarded altogether. Perhaps I don’t understand something, but it seems that the Chinese developers stupidly ripped off the compensation scheme from some other device, completely not understanding the principles of operation.

After measuring the temperature, the difference between the set and current temperatures is calculated. Depending on whether it is large or small, two formulas work - one is large, with a bunch of coefficients and the accumulation of delta (those who wish can read about building PID controllers), the second is simpler - with large differences, you need to either heat up as much as possible, or turn it off completely (depending on from the sign). The PWM variable can have a value from 0 (disabled) to 200 (fully enabled) - according to the number of interrupts in the control cycle.
When I just turned on the device (and had not yet climbed into the firmware), I was interested in one thing - there was no jitter by ± degree. Those. the temperature either keeps stable, or twitches at once by 5-10 degrees. After analyzing the firmware, it turned out that it probably always trembles. But if the deviation from the set temperature is less than 2 degrees, the firmware does not show the measured, but the set temperature. This is neither good nor bad - the jittering low-order digit is also very annoying - just need to be borne in mind.

Concluding the conversation about the firmware, I want to note a few more points.
1) I have not worked with thermocouples for 20 years already. Maybe during this time they became more linear;), but earlier, for any accurate measurements and if possible, a nonlinearity correction function was always introduced - by a formula or a table. Here this is not from the word at all. Only the zero offset and slope of the characteristic can be adjusted. High linear thermocouples may be used in all cartridges. Or the individual variation in different cartridges is greater than the possible group nonlinearity. I would like to hope for the first option, but experience hints at the second ...
2) For an incomprehensible reason for me, the temperature inside the firmware is set by a number with a fixed point and a resolution of 0.1 degrees. It is quite obvious that due to the previous remark, 10-bit ADC, incorrect correction of the cold end, unshielded wire, etc. the real measurement accuracy and 1 degree will not be in any way. Those. it looks like it was ripped off from some other device again. And the complexity of the calculations has grown a little (you have to divide / multiply 16-bit numbers by ten many times).
3) There are Rx / TX / gnd / + 5v pads on the board. As I understand it, the Chinese had special firmware and a special Chinese program that allows you to directly receive data from all three ADC channels and adjust the PID parameters. But in the standard firmware there is none of this, the conclusions are intended solely for pouring the firmware into the controller. Fill software is available, works through a simple serial port, only TTL levels are needed.
4) The points on the indicator have their own functionality - the left one indicates mode 5, the middle one - the presence of vibration, the right one - the type of displayed temperature (set or current).
5) 512 bytes are reserved for recording the selected temperature. The entry itself is made competently - each change is written in the next free cell. As soon as the end is reached, the block is completely erased, and the write is made to the first cell. When switched on, the farthest recorded value is taken. This allows you to increase the resource by a couple of hundred times.
Owner, remember - by rotating the temperature control knob, you are wasting the irreplaceable resource of the built-in nvram!
6) For the rest of the settings, the second nvram block is used

Everything is with the firmware, if you have any additional questions - ask.

Power

The final resistance of the circuit in a cold state is at least 8.7 Ohm, which gives a limiting current of 2.76A. Taking into account the drop on the key, wires and connector, the voltage on the heater itself will be about 23V, which will give a power of about 64W. Moreover, this is the limiting power in the cold state and without taking into account the duty cycle. But don't worry too much - 64 watts is a lot. And given the design of the tip, it is enough for most cases. Checking the performance in constant heating mode, I put the tip of the sting in a mug of water - the water boiled around the sting and steamed very vigorously.

But an attempt to save money using a PSU from a laptop has a very dubious efficiency - an apparently insignificant decrease in voltage leads to a loss of a third of the power: instead of 64 W, about 40 will remain. Is the savings worth $ 6?

If, on the contrary, try to squeeze the declared 70W out of the soldering iron, there are two ways:
1) Slightly increase the power supply voltage. Enough to increase by only 1V.
2) Reduce the resistance of the circuit.
Almost the only option to slightly reduce the resistance of the circuit is to replace the switch transistor. Unfortunately, almost all p-channel transistors in the used case and at the required voltage (at 30V I would not dare to put - the margin will be minimal) have similar Rdson. And so it would be doubly wonderful - at the same time, the controller board would heat up less. Now, in the maximum warm-up mode, about a watt is released on the key transistor.

Accuracy / stability of temperature maintenance

What makes sense to redo in the controller

2) Power switch with large (relatively large!) Resistance. The use of a key with a resistance of 0.05 Ohm would remove all the problems of heating it and would add about a watt of power to the cartridge heater. But the case would no longer be a 2mm dpak, but at least a size larger. Or altogether redo the control to the n-channel.

3) Transferring ntc to the pen. But then it makes sense to transfer both the microcontroller and the power switch and the reference voltage there.

4) Expansion of the firmware functionality (several sets of PID parameters for different tips, etc.). It is theoretically possible, but personally for me it is easier (and cheaper!) To re-blind on some junior stm32 than to trample into existing memory.

As a result, we have a wonderful situation - you can redo a lot of things, but almost any alteration requires throwing out the old board and making a new one. Or do not touch, to which I am inclined so far.

Conclusion

If we discard the thoughts-dreams, then the following comes out:
1) If there is no soldering station, but you want to - it's better to forget about 900 and take T12.
2) If you need cheap and precise soldering modes are not very necessary, it is better to take a simple soldering iron with power adjustment.
3) If there is already a soldering station at 900x, then T12-K is enough - versatility and portability are excellent.

Personally, I am satisfied with the purchase, but I do not plan to replace all the existing 900 stings with the T12 yet.

This is my first review, so I apologize in advance for any rough edges.

There were already plenty of reviews about soldering stations and the controllers for soldering stations themselves. But the handles for the HAKKO T12 stingers were somehow deprived of attention. About them
usually mentioned, as if in passing, like there is such or such.
So I decided to fill this gap a little.

For HAKKO T12 soldering iron tips, there are two options for handles developed by the manufacturer:
- FX-9501

- FM-2028


There is also a variant of adaptation of the handle of the 900 series of soldering HAKKO stations for use with T12 tips


As you can see from the photo, a standard plastic handle and an additional liner are used. I hope you know them, many people even use them ;-). I will not talk about the pros and cons of these pens, they are known ...
There are also exclusive pens


Nice but very expensive.
In the vastness of TaoVao, I discovered and purchased another exclusive pen


You can buy it in a well-known store in Tao. 100MHz... The store sells exclusive products of the author's design.
The pen is priced at RMB 85.00 ($ 13.24) + RMB 7 express delivery to China.
I've never seen such a handle on Ali, but on ebay available for sale . True price "Little" above.
As usual, the order arrived in a large package from Tao.


I don't know if there is any special packaging for this pen. My pen came in a regular zip-bag


The package contained: the pen itself, carefully wrapped in tissue paper


black rubber logo cuff D-ACME , rubber "tail" for the cable, 4 silicone sealing rings, 2 pieces of heat shrink with a diameter of 3mm and 5mm, as well as sensors (mercury and thermistor) in a separate small zip-bag.

The handle is machined from aluminum, then sandblasted and
anodizing the surface. Laser-engraved logo on the side
store 100MHZ .


The handle consists of two parts connected by a thread. If you unscrew the handle, you can find inside another structural element- contact block.


The contact block is similar to that of the FX-9501 handle


Only in this design, the contact block is not inserted into the handle, but screwed in.
A plastic centering ring was also found inside the handle.


Detailed photos with dimensions

Photo with a sting T12


As you can see from the photo, the T12 tip is recessed into the handle as much as possible (almost the same as in the FX-9501 handle) - that's just right for small work. The sting itself in the pile is not fixed by anything, it is inserted and removed quite easily (although it does not dangle), which means, as in the FX-9501 handle, it will rotate along the axis.

Considered the appearance, it's time to move on to practice.
We will connect the handle to the soldering station.
To connect the handle, you need a 5-core silicone wire


and GX12-5 connector

The wire was bought on TaoVao in the store at a price of 6 yuan ($ 0.93) for 1.5m + 10 yuan express delivery in China.
The GX12-5 connector was also bought at Tao, in the same store, at a price of 3 yuan ($ 0.46) + 10 yuan express delivery in China. But since everything was bought in one store and in one order, then express delivery in China is the same for the entire order.

Do not pay special attention to the seemingly expensive express delivery in China. This is the cost of shipping not one lot, but the entire purchase from one store. And if you consider that shops on Tao specialize in a product of a certain subject, then buying one product, you will definitely buy something else. As a result, the cost of delivery is evenly distributed, as a small addition to the cost of the entire purchased product.

Let's start assembling
To connect the handle, you need to know the pinout of the GX12-5 connector in the soldering station.
We find it in the above-mentioned review.
Connector GX12-5

Pinout:
1 - on the board, contact S, blue wire, position sensor (SW200 or mercury)
2 - on the board contact N, white wire, NTC thermistor
3 - on the board, contact E, green wire, grounding of the tip and common for thermistor and position sensor
4 - on the board, contact G, black wire, T12 -
5 - on the board, contact +, red wire, T12 +
For clarity, I will also give a connection diagram


According to the scheme, the left contact of the thermistor is connected to the negative contact of the soldering iron tip, in my soldering station it is connected to the green wire. In this case, it does not matter, for printed circuit board contacts E and G are combined.

We unsolder the connector, do not forget to isolate the contacts using heat shrink, and collect

Before soldering the wires to the contact block, do not forget to put the back of the handle and the "tail" on the wire. As it turned out, this is not so easy to do. The inner hole of the "tail" is 5mm, exactly the same as the diameter of the silicone wire. It was not possible to put the wire through. A drop of PMS-100 silicone oil helped

Everything went like clockwork ;-)


Now you can solder the wires to the terminal block. But first, let's place the sensors between the contacts.

The sensors should be positioned as close to the base of the terminal block as possible, as there is very little space inside the handle


"Tail" with a small inner hole did shit ...
When pulling the wire out of the back of the handle on the thermistor, one contact came off.
Had to go to the radio market and buy a new thermistor. To twice
do not step on the same rake, bought MF58-103J3950 for 10kΩ


his conclusions are more rigid and more convenient for volumetric installation


The culprit of the problems had to be squandered a little from the inside.
We solder the wires on a new one


and collect the handle.
Ready


Insert the sting


and connect to the soldering station


The station shows the temperature of the tip and the temperature sensor, the handle is ready for use.
A few minutes of working with this pen and I don't want to pick up the old one ;-)
Lightweight and convenient (no more than a marker in terms of weight and dimensions)


For comparison, the photo next to the handle of the 900 series adapted for the T12 tip


As you can see, the tip extension is not very large, much less than that of the 900 series handle with an adapter. The hand is much closer to the soldering point, it is much more convenient to solder small radioelements.

Observant, those who carefully looked at the photos of the delivery kit, probably noticed 4 silicone O-rings. I turned them in my hands for a long time and wondered what they are used for? Not a word about them on the store page.
The only place they can be applied is to place them under the centering ring.


I wrote a letter to the seller asking him to clarify the purpose of these rings. In the meantime, I installed one below the centering ring - the sting became tighter "to sit in the handle". But this did not save the sting from turning along the axis.
Without waiting for a response from the Chinese, he began to carefully examine the drawing with the inner section of the handle. I was interested in the groove inside the handle


In this groove, in the end, I installed a rubber ring

The sting fits snugly in the handle, but still has, although not great, the ability to rotate along the axis.

Summarize.

My subjective pluses:
- high-quality workmanship, the handle pulls more on a gift or collection version than on a tool for everyday work
- well thought-out design
- fits comfortably in the hand
- a small removal of the sting from the handle itself

Minuses:
- the tip does not have a rigid fixation in the handle and can rotate along the axis when soldering radio components
- the price, after all, $ 13 is not a small amount of money for a "simple handle" for a soldering iron.

That's all.
Thank you all for your attention, I look forward to constructive criticism and comments.

I bring to your attention an overview of the Chinese soldering station based on the STC controller for the Hakko T12 tips.
I'll tell you right away how it differs from the stations on the STM32 controller. The STC does not have a T12 tip library (which is used for individual tip calibration), so there is no individual tip calibration and there is no clock. STM32 allows you to memorize 3 calibration points for each of its tips.

Immediately I apologize, for some reason unknown to me, my photos are not attached to the review (perhaps they are too large, only greatly reduced screen shots were attached) + I simply do not have a lot of things, I will use other people's photos.

Station selection.
Researching forums and articles led me to believe that I needed a temperature controlled soldering iron.
There are several options for soldering irons with a built-in temperature regulator in the handle, they are relatively cheap and are quite suitable for amateur purposes.
But appetite comes with eating))) I really wanted a high-quality soldering iron and, if possible, with digital adjustment.
Everything is simple here - if inexpensive, then either relative quality or temperature control.
Popular in this category.


A more expensive alternative is 900 series tip soldering stations, for example from Lukey.

There are a lot of such stations, including those with hair dryers (it would be convenient for me to plant shrink cambric), but in budget options there is one known drawback - a small gap between the heating element and the sting, which prevents rapid heat exchange between them. According to many, this gap is needed to compensate for thermal deformations. They say the problem can be easily treated with a lump of foil or a "file", but somehow I didn't like it right away.
A soldering iron was also recommended, it does not have such a gap. I didn’t like the need to buy a power supply unit and “collective farm” connector. It is not included in the kit.

As a result, my choice fell on the T12 soldering station. These tips are also devoid of unnecessary gaps, due to the fact that the heating element, thermocouple and the tip itself are soldered into one body, but they are more popular and their range is much wider.
Similar stings are used by other manufacturers, they have been known since the mid-70s and have proven themselves well in work.
... By the way, they are similar, but sold in other regions.
Several variants of Chinese stations on T12 tips were discovered, as it turned out later, even more than I expected. You can buy them in the form of finished products (I did so), or in parts, combining them as you wish. I chose a ready-made version, so the kit came out for about the same money, and I did not have another soldering iron for assembling the kits.
They differ in the case, power supply, controller and screen, pen. Well, you can choose any sting. V ready-made versions usually you can ask to invest what you want, they say the Chinese do not refuse.

I also included a yellow tip cleaning sponge, rosin, and a grounded power cord. By the way, the sting is securely connected to the ground.

Station control
There is a switch on the back of the case. The station is controlled by rotating the encoder and short and long pressing on it.
Below are photos of the menu, work screen, Standby and Sleep modes.

Small addition from 04/03/2017.
The old handle let me down a couple of times, the textolite basket was soldered. I decided to buy a new one. I am reporting ...
The FX-9501 pen I ordered came. I watched it, tested it and ... put it off until better (or worse?) Times.
I didn’t like it.
The photo above shows my old pen (951) and a new one.

First, about the pros. The main reason why I took a new pen was in the old very unreliable textolite basket:

In the new one, everything is much more modern, more beautiful and more reliable:

On this we finished with pluses. Not a lot of them, yes ...

Minuses.
First, the rubber seal is loose:


Why this is so is completely incomprehensible. But it is clearly thinner than it should be.

Secondly, the inscription is already initially shabby, "antique":

The sting has a little backlash in the handle, but I think this is not critical.

The sting also does not fix it with a nut, but is simply inserted into the handle. And it fits deeper than the old handle.
It seems like it should be convenient ... For this, many people buy it. But there are nuances ...
In the old sting, the fixing nut is located relatively farther from the tip of the sting; in this part, the sting is no longer hot and the nut can be unscrewed by hand during operation. I changed the tip like this without turning off the soldering iron.
This trick won't work in a new pen. The part of the sting that sticks out already hot.

As a result of the deep seating of the sting, the part of the handle that you hold onto is noticeably heated during work. Not that it burned, but unpleasant. With the old handle, this could not be.

Well, one more thing, the new pen does not hold well in the holder:

Well, okay, for a spare pen it will go.

There is another oddity with her. If you turn it over with a sting upwards, then the temperature sensor starts to fail, and, accordingly, the temperature "floats". If you hold it this way longer, then the station shows instead of the cold junction temperature "? 20", which means "sensor error" in Chinese.
In the working position (sting down), such an error does not seem to occur.
This probably has something to do with the fact that the green wire is common for the temperature sensor and the ball position sensor. It's just not clear why there is no such problem with the old handle, although the wiring and sensors are the same.

In conclusion, I will give a few links to comments in other reviews and just useful links. The information has not been verified by me, check its accuracy yourself.

The popular Hakko T12 kit allows you to make a good soldering station for little money. This set has already been reviewed at Muska, which is why I decided to purchase it. Under the cut is my experience in assembling a station in a case from available components. Perhaps it will be useful to someone.

What happened in the end.

The handle assembly is described in detail in the previous review, so I will not consider it. I will only note that the main thing is to be careful when positioning the contact pads. It is important that both pads for soldering the spring-loaded contact are next to each other on the same side, because if you make a mistake, it is quite difficult to re-solder. I've seen this error on several youtube reviewers.

Since the Chinese picture with the pinout looks a little confusing, I decided to draw a more understandable one. The order of contacts from the vibration sensor to the controller does not matter.

In the comments, a dispute arose about the correct position of the vibration sensor, it is also the SW-200D angle sensor. This sensor is used to automatically switch the soldering iron to standby mode, in which the temperature of the tip becomes 200C until the soldering iron is again taken into the hand. Experimentally, the only correct position of the sensor was established. The transition to sleep mode occurs if no changes come from the sensor for more than 10 minutes and, accordingly, the exit from sleep mode occurs if at least some fluctuations were recorded.


In this sensor, vibration readings are possible only at the moment when the balls touch the contact pad. If the balls are in the glass, then no data will be received. Therefore, the sensor must be soldered with the glass upwards, and with the contact pad towards the tip. The glass at the sensor looks like an all-metal face, and the contact pad is made of yellowish plastic.

If you place the sensor with the glass down (towards the tip), then the sensor will not work with the vertical position of the soldering iron and it will have to be shaken to get out of sleep mode.

The sleep timeout can be adjusted in the menu. To go to the configuration menu, hold down the button on the knob (press the temperature regulator) with the controller powered off, turn on the controller and release the button.
The time to enter sleep mode is adjusted in P08. You can set a value from 3 minutes to 50, others will be ignored.
To move between menu items, briefly hold down the knob button.

P01 ADC reference voltage (obtained by measuring the TL431)
P02 NTC correction (by setting the temperature to the lowest reading on the digital observation)
P03 op amp input offset voltage correction value
P04 thermocouple amplifier gain
P05 PID parameters pGain
P06 PID parameters iGain
P07 PID parameters dGain
P08 automatic shutdown time setting 3-50 minutes
P09 restore factory settings
P10 temperature settings stepping
P11 thermocouple amplifier gain

In order to squeeze out the maximum power from the soldering iron, it must be supplied with a voltage of 24V. When powered at 19V and above, do not forget to remove the resistor

Components used

Most useful was T12-BC1

It turned out that for each tip it is necessary to calibrate the temperature separately. I managed to achieve a discrepancy of a couple of degrees.

In general, I am very pleased with the soldering iron. Together with normal flux, I learned to solder SMD at a level that I had never dreamed of before.