Handle for soldering tips HAKKO T12 with TaoVao. Choosing a soldering station for Hakko T12 tips T12 soldering station

I bring to your attention a review of a Chinese soldering station based on the STC controller for tips Hakko-type T12.
I’ll tell you right away how it differs from the stations on the STM32 controller. There is no T12 tip library on the STC (which is used for individual tip calibration), therefore there is no individual tip calibration and no clock. STM32 allows you to remember 3 calibration points for each of its tips.

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

Station selection.
Studying forums and articles led me to the idea that I need a soldering iron with temperature control.
There are several types of soldering irons that have a temperature controller built into the handle, they are relatively cheap and quite suitable for amateur purposes.
But the 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 soldering stations, such as those made by Lukey.

There are a lot of such stations, including those with hair dryers (it would be convenient for me to plant heat-shrink tubing), but in budget options there is one well-known minus - a small gap between the heating element and the tip, which prevents rapid heat transfer between them. According to many, this gap is needed to compensate for thermal deformations. They say the problem is easily treated with a piece 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 that you need to buy a power supply and “collective farm” connector. It is not included in the kit.

As a result, my choice fell on a soldering station with T12 tips. These tips are also devoid of unnecessary gaps, due to the fact that the heating element, the thermocouple and the tip itself are soldered into one body, but they are more popular and their range is much wider.
Similar stings are also 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 found, as it turned out later, even more than I expected. You can buy them as 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 to assemble the kits.
They differ in body, power supply, controller and screen, handle. Well, you can choose any sting. In ready-made options, you can usually ask to invest what you want, they say the Chinese do not refuse.

In the kit I also had a yellow sponge for cleaning the sting, rosin and a power cord with grounding. By the way, the sting is securely connected to the ground.

Station control
On the back wall housing has a switch. The station is controlled by rotating the encoder and short and long presses on it.
Below are photos of the menu, work screen, Standby and Sleep modes.

A small addition from 04/03/2017.
The old pen let me down a couple of times, the textolite basket was unsoldered. Decided to buy a new one. I report...
The FX-9501 pen I ordered arrived. I looked at it, tested it and ... put it off until better (or worse?) Times.
I didn't like her.
Pictured above is my old pen (951) and the new one.

First about the pros. The main reason I took a new pen was that the old one had a very unreliable textolite basket:

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

That's it with the pluses. Not many, yes...

Minuses.
First, the rubber seal dangles:


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

Secondly, the inscription is already initially shabby, “antique”:

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

Another sting does not fix with a nut, but is simply inserted into the handle. And it is inserted deeper than in the old pen.
It seems like it should be convenient ... For the sake of this, many people buy it. But there are nuances...
In the old tip, the fixing nut is relatively further from the tip of the tip, in this part the tip is no longer hot and the nut can be unscrewed by hand during operation. I changed the tip without turning off the soldering iron.
In the new pen, such a focus will not work. That part of the sting that sticks out is already hot.

As a result of the deep landing of the sting, the part of the handle that you hold on to noticeably heats up in operation. Not that it would burn, but unpleasant. This could not have happened with the old pen.

And yet, the new pen does not hold well in the holder:

Oh well, for a spare pen will go.

There is another oddity with her. If you turn it upside down, the temperature sensor starts to fail, and, accordingly, the temperature “floats”. If you hold it like this longer, then the station shows "? 20" instead of the cold junction temperature, which in Chinese means "sensor error".
In the working position (sting down), such an error does not seem to occur.
This is probably somehow related to the fact that the green wire is common to the temperature sensor and the ball position sensor. It’s just not clear why there is no such problem with the old pen, 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. This information has not been verified by me, please check it yourself.

Reading local reviews, I have repeatedly thought about buying a soldering iron with a T12 tip. For a long time I wanted something portable on the one hand, powerful enough on the other hand, and, of course, maintaining the temperature normally.
I have a relatively large number of soldering irons, bought at different times and for different tasks:
There are very ancient EPSN-40 and a 90W Moskabel, a slightly newer EMP-100 (hatchet), a completely new Chinese TLW 500W. The last two are especially good at retaining temperature (even when soldering copper pipes), but soldering microcircuits with them is not very convenient :). An attempt to use the ZD-80 (pistol with a button) did not work out - neither power nor normal temperature maintenance. Other "electronic" trifles such as Antex cs18 / xs25 are suitable only for very small things, and they have no built-in adjustment. About 15 years ago I used den-on "ovskim 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, there won't be even a third on the sting.
As a stationary option, I've been using Lukey 868 for 10 years (it's practically 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 small bag.
Because at the time of purchase, I was not yet sure “do I need it”, the minimum was taken a budget option with a K-tip and a handle that is as similar as possible to the usual soldering iron from Lukey. It is possible that for some it does not seem very convenient, but for me it is more important that the handles of both soldering irons used are habitually and equally in the hand.
Further review can be 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 give a link to a snapshot of the product from the order log. However, there is no problem to find a similar product.

Part 1 - construction

After a mock test of performance, the question arose about the choice of design.
There was an almost suitable power supply (24v 65W), almost 1: 1 high with a control board, a little narrower than it and about 100mm long. Considering that this power supply fed some kind of dead (not his fault!) connected and not cheap lucent piece of iron, and its output rectifier has two diode assemblies for a total of 40A, I decided that it is not much worse than the one common here Chinese on 6A. At the same time, it will not roll.
Test check on a time-tested load dummy (PEV-100, unscrewed by about 8 ohms)


showed that the PSU practically does not heat up - in 5 minutes of operation, the key transistor, despite its insulated case, heated up to 40 degrees (slightly warm), the diodes are warmer (but it doesn’t burn the hand, it’s quite comfortable to hold), and the voltage is still 24 volts with pennies. Emissions increased to hundreds of millivolts, but for this voltage and this application, this is quite normal. Actually, I stopped the experiment because of the load resistor - about 50W stood out on its smaller half and the temperature exceeded a hundred.
As a result, the minimum dimensions were determined (PSU + control board), the next step was the case.
Since one of the requirements was portability, up to the ability to shove it into your pockets, the option with ready-made cases disappeared. Available universal plastic cases did not fit at all in size, Chinese aluminum cases under T12 for jacket pockets are also too big, and I didn’t want to wait another month. The option with a "printed" case did not pass - neither strength nor heat resistance. Having estimated the possibilities and remembering the pioneer youth, I decided to make it from the ancient one-sided foil fiberglass, lying around since the times of the USSR. Thick foil (a micrometer on a carefully smoothed piece showed 0.2mm!) still did not allow etching tracks thinner than a millimeter due to lateral etching, but for the body - that's it.
But laziness, coupled with an unwillingness to dust, categorically did not approve of sawing with a hacksaw or cutter. After assessing the available technological capabilities, I decided to try the option of sawing textolite on an electric tile cutter. As it turned out - a highly convenient option. The disk cuts fiberglass without any effort, the edge turns out to be almost perfect (you can’t even compare with a cutter, hacksaw or jigsaw), the width along the length of the cut is also the same. And, importantly, all the dust remains in the water. It is clear that if you need to saw off one small piece, then unfolding the tile cutter is too long. But even for this small body, it was necessary to cut a meter.
Next, a case with two compartments was soldered - one for the power supply, the second for the control board. Initially, I didn't plan the separation. But, as in welding, plates soldered into a corner tend to reduce the angle when they cool, and an additional membrane is very useful.
The front panel is bent from aluminum in the shape of the letter P. The upper and lower bends are threaded for fixing in the case.
The result is this (I am still “playing” with the device, so the painting is still very rough, from the remnants of an old spray can and without polishing):

The overall dimensions of the body itself are 73 (width) x 120 (length) x 29 (height). The width and height cannot be made smaller, because the control board measures 69 x 25, and finding a shorter power supply is also not easy.
At the back there is a connector for a standard electrical wire and a switch:


Unfortunately, the black microswitch was not in the trash, it will be necessary to order it. On the other hand, white is more noticeable. But I specifically set the connector as standard - this allows in most cases not to take an additional wire with me. Unlike the option with a laptop outlet.
Bottom view:

The black rubber insulator was left over from the original power supply. It is quite thick (a little less than a millimeter), heat-resistant and very difficult to cut (hence the rough cutout for the plastic spacer - it almost didn't fit). Feels like asbestos impregnated with rubber.
To the left of the power supply is the rectifier radiator, to the right is the key transistor. In the original PSU, the radiator was a thin strip of aluminum. I decided to "aggravate" just in case. Both heatsinks are isolated from the electronics, so they can freely adhere to the copper surfaces of the case.
An additional heatsink for the control board is mounted on the membrane, contact with d-pak cases is provided by a thermal pad. There are not many benefits, but everything is better than air. To eliminate the short circuit, I had to bite off the protruding contacts of the "aviation" connector a little.
For clarity, a soldering iron next to the case:

Result:
1) The soldering iron works approximately as stated and fits perfectly in the pockets of the jacket.
2) Recycled in the old trash and no longer lying around: a power supply, a piece of fiberglass 40 years old, a can of nitro enamel made in 1987, a microswitch and a small piece of aluminum.

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

Part 2 - Operation Notes

As you can see, in the first part, I did not mention at all how it all works. It seemed to me appropriate not to confuse the description of my personal design (rather "collective-farm self-made" in my opinion) and the functioning of the controller, which is identical or similar to many.

As a preliminary warning, I would like to say:
1) Different controllers have slightly different circuitry. Even externally identical boards can have slightly different components. Because I only have one particular device of mine, I can't guarantee a match with others in any way.
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 do not at all claim to be a pioneer. Many points have already been previously covered by other reviewers.
4) Then there will be a lot of boring letters and not a single funny picture. If a internal organization not interested - stop here.

Design overview

Further calculations will be largely related to the controller circuitry. To understand its operation, the exact scheme is not necessary, it is enough to consider the main components:
1) STC15F204EA microcontroller. Nothing particularly outstanding chip of the 8051 family, noticeably faster than the original (original 35 years ago, yes). It is powered by 5V, has a 10-bit ADC with a switch, 2x512 bytes nvram, 4K program memory.
2) Stabilizer for + 5V, consisting of 7805 and a powerful resistor to reduce heat dissipation (?) by 7805, with a resistance of 120-330 ohms (different on different boards). The solution is extremely low-cost and heat-generating.
3) Power transistor STD10PF06 with strapping. Works in key mode at low frequency. Nothing outstanding, old man.
4) Thermocouple voltage amplifier. The trimmer adjusts its gain. It has protection at the input (from 24V) and is connected to one of the inputs of the ADC MK.
5) Reference voltage source on TL431. Connected to one of the inputs of the ADC MK.
6) Board temperature sensor. Also connected to the ADC.
7) Indicator. Connected to MK, works in dynamic indication mode. I suspect that one of the main consumers + 5V
8) Control knob. Rotation regulates the temperature (and other parameters). The button line in many models is not soldered or cut. If connected, it allows you to configure additional parameters.

As you can see, all functioning is determined by the microcontroller. Why the Chinese put just this one - I don’t know, it’s not very cheap (about $ 1, if you take a few pieces) and back to back 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 (obvious tails of the library are visible there).

Functioning of the controller firmware

I don't have the source code, but IDA hasn't gone away :). The mechanism of operation is quite simple.
At initial startup, the firmware:
1) initializes the device
2) loads parameters from nvram
3) Checks if the button is pressed, if it is pressed, it waits for release and starts the p / p settings of advanced parameters (Pxx) There are many parameters, if there is no understanding, then it is better not to touch them. I can lay out the layout, but I'm afraid to provoke problems.
4) Displays "SEA", waits and starts the main work loop

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) Alternate control mode

After starting, mode 1 works.
With a short press of the button, the transition to mode 5 is made. There you can turn the knob 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 debate about how to properly install the vibration sensor. According to the firmware I have, I can say unequivocally - no difference. The transition to the partial power saving mode is performed in the absence of 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 for 3 minutes. The 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 tip temperature will inevitably float. And if a deviation of more than 5 degrees from the set value is fixed, there will be no exit to the energy 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 energy saving to partial.

The MK is engaged in maintaining the temperature in one of the timer interrupts (two of them are involved, the second is engaged in the display and other things. Why this is done is not clear - the interrupt interval and other settings are the same, it was quite possible to do with a single interrupt). The control cycle consists of 200 timer interrupts. At the 200th interruption, the heating is necessarily turned off (- as much as 0.5% of the power!), A delay is performed, after which the voltages are measured from the thermocouple, temperature sensor and reference voltage from TL431. Further, all this is converted into temperature using formulas and coefficients (partially specified in nvram).
Here I will allow myself a small digression. Why a temperature sensor in such a configuration is not entirely clear. When properly organized, it should give a temperature correction at 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. You either need to transfer it to the pen, as close as possible to the T12 cartridge (and another question is where the cold junction of the thermocouple is located in the cartridge), or throw it away altogether. Perhaps I don’t understand something, but it seems that the Chinese developers stupidly torn the compensation scheme from some other device, completely not understanding the principles of operation.

After measuring the temperature, the difference between the set temperature and the current temperature is calculated. Depending on whether it is large or small, two formulas work - one large, with a bunch of coefficients and accumulation of deltas (those who wish can read about the construction of PID controllers), the second is simpler - with large differences, you need to either heat it 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 loop.
When I just turned on the device (and had not yet got into the firmware), I was interested in one moment - there was no jitter by ± degrees. Those. The temperature either keeps stable, or twitches immediately by 5-10 degrees. After analyzing the firmware, it turned out that it was apparently always trembling. But if the deviation from the set temperature is less than 2 degrees, the firmware shows not the measured, but the set temperature. This is neither good nor bad - the trembling low bit is also very annoying - just something to keep 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 have become linear;), but earlier, for any accurate measurements and if possible, the non-linearity correction function was always introduced - by a formula or a table. Here it is not from the word at all. Only zero offset and slope can be adjusted. Maybe all cartridges use high-linear thermocouples. Either the individual spread in different cartridges is greater than the possible group non-linearity. I would like to hope for the first option, but experience hints at the second ...
2) For some reason I don't understand, inside the firmware the temperature is set as a fixed point number with a resolution of 0.1 degrees. It is quite obvious that due to the previous remark, 10-bit ADC, incorrect cold end correction, unshielded wire, etc. the real accuracy of measurements and 1 degree will not be in any way. Those. It looks like it was ripped off again from some other device. And the complexity of calculations has slightly increased (repeatedly you have to divide / multiply by ten 16-bit numbers).
3) There are contact pads Rx/TX/gnd/+5v 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 there is nothing of this in the standard firmware, the outputs are intended solely for uploading the firmware to the controller. The fill program 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 allotted for recording the selected temperature. The entry itself was done correctly - each change is written to the next free cell. As soon as the end is reached, the block is completely erased, and the entry is made in the first cell. When enabled, the furthest recorded value is taken. This allows you to increase the resource by a couple of hundred times.
Owner, remember - by turning the temperature knob, you are wasting an irreplaceable resource of the built-in nvram!
6) For other settings, the second nvram block is used

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

Power

One of the important characteristics of a soldering iron is the maximum power of the heater. You can evaluate it as follows:
1) We have a voltage of 24V
2) We have a T12 sting. The cold tip resistance I measured is just over 8 ohms. I got 8.4, but I do not presume to claim that the measurement error is less than 0.1 Ohm. Let's assume that the real resistance is no less than 8.3 Ohm.
3) The resistance of the STD10PF06 key in the open state (according to the datasheet) - no more than 0.2 Ohm, typical - 0.18
4) Additionally, you need to take into account the resistance of 3 meters of wire (2x1.5) and connector.

The resulting cold circuit resistance is at least 8.7 ohms, which gives a current limit 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 64 watts. Moreover, this is the maximum power in a cold state and without taking into account the duty cycle. But do not get too upset - 64 watts is quite a lot. And given the design of the sting, it is enough for most cases. Checking the performance in the constant heating mode, I placed the tip of the sting in a mug of water - the water around the sting boiled and soared very cheerfully.

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

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

Temperature accuracy/stability

In addition to power, temperature stability is equally important. Moreover, for me personally, stability is even more important than accuracy, because if the value on the indicator can be selected empirically - I usually do this (and it’s not very important that at an exhibition of 300 degrees it’s really on the sting - 290), then instability cannot be overcome in this way . However, according to the sensations, the temperature stability on the T12 is noticeably better than on the stings of the 900 series.

What makes sense to redo in the controller

1) The controller is getting hot. Not fatal, but more than desired. Moreover, it is mainly not even the power unit that heats it, but the 5V stabilizer. Measurements showed that the current at 5V is about 30 mA. 19V drop at 30mA gives approximately 0.6W of continuous heating. Of these, about 0.1W is allocated on the resistor (120Ω) and another 0.5W on the stabilizer itself. The consumption of the rest of the circuit can be ignored - only 0.15W, of which a significant part is spent on the indicator. But the board is small and there is simply nowhere to put a step-down - if only on a separate scarf.

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

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

4) Extension of firmware functionality (several sets of PID parameters for different tips, etc.). Theoretically possible, but personally it’s easier (and cheaper!) for me to re-blind on some younger 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 you to throw out the old board and make a new one. Or don't touch it, which is what I'm leaning towards for now.

Conclusion

Does it make sense to switch to T12? Don't know. For now, I'm only working with the T12-K tip. For me, it is one of the most versatile - and the polygon heats up well, and you can solder / unsolder the comb of leads with an ersatz wave, and you can warm up a separate lead with a sharp end.
On the other hand, the existing controller and the lack of automatic identification of a particular type of tip complicates the work with the T12. Well, what prevented Hakko from putting some sort of identifying resistor/diode/chip inside the cartridge? It would be ideal if the controller had several slots for individual settings sting (at least 4 pieces) and when changing the sting, he automatically loaded the necessary ones. And in the existing system, you can do as much as possible manual selection sting. Estimating the amount of work, you understand that the game is not worth the candle. Yes, and the cost of cartridges is commensurate with the whole soldering station (if you do not take China for $5). Yes, of course, you can experimentally display a table of temperature corrections and stick a plate on the lid. But with the PID coefficients (on which stability directly depends), this cannot be done. From sting to sting, they must be different.

If we discard 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 accurate soldering modes are not much needed - it's better to take a simple soldering iron with power control.
3) If you already have a soldering station for 900x, then T12-K is enough - versatility and portability turned out to be on top.

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

This is my first review, so I apologize in advance for possible roughness.

Assembly of a soldering station on Hakko T12

The article briefly describes the prerequisites for choosing a soldering station specifically on Hakko T12 tips, the following is comparative analysis several versions available on the market, as well as some features of the assembly of the soldering station and its final settings.

Why such a hype around the Hakko T12?

To understand why many radio amateurs have become so interested in these Chinese stations lately, you need to start from afar. If you have already come to this decision yourself, you can skip this chapter.

For any beginner to learn how to solder, the first question that arises is the choice of a soldering iron. Many start with fixed-power penny soldering irons available at the nearest hoz.mage. Of course, some simple work, such as soldering wires, can be done even with a Soviet soldering iron with a copper tip, especially if you have the skill. However, for anyone who has tried to solder something more technologically advanced with such a solder, problems become obvious: if the soldering iron is too weak (40W or less) - some details, for example, leads connected to an earthen polygon, are very inconvenient to solder, and if it is powerful (50W or more ) - it overheats very quickly and instead of soldering, ritual burning of the tracks takes place. Based on the foregoing, even if you are just learning how to solder, it is still advisable to buy a soldering iron with the ability to adjust the temperature. However, most often soldering irons with simple regulators built into the handle are of extremely poor quality, so if you are already wondering about choosing a normal soldering iron, you should probably already look towards soldering stations.

Most often, the next question is which soldering station to choose. There may be variations here, since professionals mainly work with rather bulky stations combined with a soldering gun, such as PACE, ERSA or, at worst, Lukey. I don’t need a hair dryer at home, but at the same time I want to have a reliable, powerful and compact station with the ability to adjust. As workplace not rubber, the station should be really small, so many stations fall away in size. Plus, of course, you always want to meet a reasonable budget. And here our Chinese friends enter the stage, with their stations designed to work with the stings of a Japanese company Hakko. The original soldering stations from this brand cost some inadequate money, but the Chinese crafts for these tips, oddly enough, are of fairly high quality, at a very pleasant price.

So why are the stings from Hakko? Their main trump card is a ceramic heater combined with a temperature sensor. Actually, for a finished soldering station, all that remains is to “add” a PID controller and sufficient power to such a tip, which allows you to achieve fast heating and high-quality maintenance of the set temperature. Well, wrap it all in a convenient case. Actually, in soldering stations-constructors, which can be found in abundance on Aliexpress at the request of the type diy hakko t12, all this is implemented, and in the kit, the Chinese usually put one or two Hakko stings (there is an opinion that these are mostly copies, however, even the quality of the copies is at the level).

Choosing a build kit

If you have already tried to search for a similar soldering iron on Ali, you are probably surprised by the variety of options that the search gives.

At the beginning of 2018, in the search on Ali, offers from the "firms" Quicko, Suhan and Ksger most often come across. Moreover, in the descriptions they sometimes even refer to each other, so it is quite obvious that this is the essence of the same thing, so further on, if possible, I will skip the specific names of the "manufacturer", referring only to versions of specific stations, because a cursory analysis of photographs suggests that if the versions are the same, then the circuitry is approximately the same.

In fact, there are not as many variations in general as it might seem at first glance. I will describe the main significant differences:

An approximate table of soldering iron power, depending on the voltage of the power supply:

• At 12V - 1.5A (18 W)
• At 15V - 1.88A (28W)
• At 18V - 2.25A (41 W)
• At 20V - 2.5A (50W)
• At 24V (max!) - 3A (72 W)

note, for some versions it is indicated that when using a power supply above 19V, it is desirable to unsolder a 100 Ohm resistor, signed somehow like "20-30V R-NC". This resistor is in parallel with a more powerful 330 ohm resistor and together they form one 77 ohm resistor connected in front of the 78M05 chip. Having unsoldered 100 ohms, we will leave one resistor at 330. This was done in order to reduce the voltage drop across this regulator at a high input voltage - obviously to increase its reliability and durability. On the other hand, by raising the resistance to 330 we will also limit the maximum current on the +5V line. At the same time, given that the 78M05 itself can easily digest even 30V at the input, I would not solder 100 Ohms completely, but would replace this resistor with something in the range of 200-500 Ohms (the higher the voltage, the higher the rating). Or you can not touch this resistor at all and leave it as it is.

So, we have decided on the general package, now let's take a closer look at the boards of various versions themselves.

Comparison of some versions

Now on sale you can find a car of various stations under different names, it is not clear how different. I already wrote above that I bought myself a station on the STC, so I will only compare the versions on this controller.

The circuitry for all boards is quite similar, small nuances may vary. I found a diagram online drawn by user Wwest from ixbt.com for the version F. In principle, it is quite enough to understand the operation of the station.

Scheme of soldering station Mini STC T12 ver.F

To begin with, under the spoilers below are comparative photos of two versions of the Mini STC T12 ver.E and ver.F :

Appearance Mini STC T12 ver.E

Appearance Mini STC T12 ver.F

The first thing that catches your eye is the absence of an electrolytic capacitor between the indicator and the encoder in the version F, as well as a slightly smaller number of details. It looks like the electrolyte was changed to ceramic closer to the 78M05 outlet, but it's hard to tell the capacitance of the ceramic from the photo. If there is something in the spirit of 10 microfarads or more, then, given the small load power, this is quite acceptable. In schema for version F this capacitor is marked as tantalum at 47 uF, probably the author of the circuit had a board from Diymore (see below). Also, in more new version changed the contact pads for the NTC thermistor (in the version E it is designated as R 11) for a larger size, and reduced the number of individual resistors by assembling them in another assembly - this simplifies the purchase of parts, reduces the likelihood of installation errors and increases overall manufacturability, which can clearly be written as a plus. In addition, the electrolytic capacitor, which could be dispensed with, can also be written down for the version E.

In total, as an intermediate conclusion, we can conclude the following: if you have the opportunity to replace the electrolyte with a polymer, then it is better to take the version E. If you don’t care what to change, it’s better to buy more capacious ceramics and take the version F. And if you don’t want to change anything at all, then the question comes down to what will fail faster, electrolyte, or a controller with unstable power. Given that the version F the overall manufacturability is higher, perhaps I would recommend it.

Less common are two more board options - from Ksger and Diymore, and they show that the board trace has been further developed.

Appearance Diymore Mini STC T12 (version unknown)

Appearance of Ksger Mini STC T12 LED (version unknown)

Personally, I like the version from Ksger the most - it is clear that it is bred with love. However, the capacitor mentioned earlier here is definitely no more than 1206 - there are practically no available 10 microfarad ceramics with a voltage of more than 20V for this size on the market, so, most likely, something small is worth here in order to save money. This is a minus. In addition, the AOD409 power mosfet has been replaced with some kind of transistor in a SOIC package, which, in my opinion, has worse heat transfer.

The Diymore version has tantalum and a regular AOD409 in a DPAK case, so although it is less visually attractive, it is clearly preferable when choosing. Unless you are ready to solder these elements yourself.

Total: if you don’t care what to buy at all and you don’t want to solder anything after purchase, I would advise you to look for a version similar to the photo of the board from Diymore, or, if you are too lazy, take the version F and change the capacitors as described above.

Assembly

In general, the assembly of the soldering iron is trivial, apart from the fact that you will need another soldering iron to assemble (smile). However, as usual, there are a few caveats.

Assembling the soldering iron handle. The connector contacts on the board and in the handle may have different markings. This is hardly a problem, since there are only five wires anyway:

• Two power wires - plus and minus
• temperature sensor wire
• Two vibration sensor wires (order is not important)

On the controller board, the temperature sensor wire is most often signed with one letter E. One of the contacts of the vibration sensor is signed SW, and the second can be soldered to any hole marked minus " − ". In fact, I don’t really understand at all why it was necessary to lead a separate wire from the handle for the minus of the sensor, given that it still goes to the ground, but perhaps this was done for less noise.

If the contacts on your pen are not signed in any way, it is enough to know that there are only three contacts on the sting itself: plus (closest to the end on the sting), then there is a minus and a temperature sensor output. For clarity, I buried the scheme with Ali.

The Chinese sometimes sign the thermocouple output as ground, and in the controller itself E is connected to ground - as far as I understand, this is not entirely correct, although I'm too lazy to figure it out, and I still don't have ground.

In some versions, in addition to the vibration sensor, you also need to solder a capacitor in the handle. I do not know for sure, but the conder can be between the plus and minus of the heater - so that it makes less noise in the RF range. It can also be a conduit between the temperature sensor and the ground - again, in order for the temperature sensor readings to be smoother and less noisy. I don’t know how expedient all this is - for example, there was no place for a capacitor in my pen at all. In addition, some users wrote that the accuracy of thermal stabilization with closed capacitor leads was higher. In general, if this capacitor is provided in your model, you can try this way and that.

Judging by the reviews on the Internet, in addition to the capacitor and vibration sensor, some pens also had a thermistor, supposedly to control the temperature of the cold end. However, then the manufacturers realized that the sensor cold side it is logical to place them directly on the controller board and they don’t suffer from such garbage anymore.

About the vibration sensor. As a vibration sensor in such stations, either SW-18010P (rarely) or SW-200D (mostly) vibration sensors are used. Some more craftsmen use mercury sensors - I am generally not a supporter of the use of mercury in the economy, so I will not discuss this approach here.

SW-18010P is a conventional spring in a metal case. They write that such a sensor is much less convenient for a soldering iron than the SW-200D, which is a simple metal "cup" with two balls inside. I had two SW-200Ds in the kit, and I advise you to use them.

The vibration sensor is needed to automatically switch the station to standby mode, in which the tip temperature decreases until the soldering iron is picked up again. The function is ultra-convenient, so I highly recommend that you do not refuse the sensor.

Judging by the picture with the handle connection diagram, the Chinese advise soldering the sensor with a silver pin towards the sting. I actually did exactly that and it works very well for me.

However, for some reason this sensor does not work properly for some - they write that the soldering iron has to be shaken to wake it from sleep mode and explain this with a picture from which it is obvious that if the sensor is tilted towards the handle, there can be no contact until it is shake it up. In general, if in your case the station does not wake up when you just take a soldering iron, try soldering the vibration sensor with the reverse side.

There is one more hint - some cunning people advise soldering two sensors in parallel and in different directions, then everything should work in any position of the soldering iron. Indirectly, this assumption is confirmed by the fact that the Chinese put two sensors in many kits, and on the handle itself there are two places next to where it is very convenient to solder them - most likely just for this. Everything worked for me right away, so I did not check the hint.

If you still don’t want to use the auto-off function at all, or you don’t like how the vibration sensor rattles, you can turn it off simply by closing the SW and + on the controller board, and do not solder the wires going to the handle at all.

About the body. As I wrote above, I chose the standard aluminum case that is offered for these stations. And overall, I'm happy with my choice. There are several points to which you should pay attention.

First, you need to somehow fix the power supply in the case. I solved this tritely by drilling four holes in the case and attaching the power supply to the screws. In my case, the power supply was just a separate board with radiators, and, because. the case is aluminum, it was necessary to make some bosses so that the power supply board does not lie directly on the case. For this, I cut out two strips of plexiglass, in which I drilled two holes for the screws, and on this the problem was solved. You can also, for example, cut insulating rings of the desired height from some polymer tube, but it seemed to me that the idea with Plexiglas strips is simpler.

Secondly, I relied on the gloomy Chinese genius and did not check the dimensions of the case and power supply. It was a mistake. As you can see from the photo below, it turned out that after installing the controller, my block fits into the case almost back to back, which is not good. I had to unsolder the output terminals of the block and solder the wires with the controller power connector directly to the power supply board. If there were no connector on the controller board, the block would turn out to be non-separable, which would be much less convenient. On the 220V side, I added additional insulation with heat shrink and a drop of hot melt adhesive. You can also see a strip of hot melt on the 220V connector - so that it dangles less.

In general, despite the fact that everything fit with minimal gaps, it turned out acceptable, but the sediment remained.

About the power supply and controller improvements. As I wrote above, I had a version station E with normal electrolyte. Everyone knows that ordinary electrolytes tend to dry out over time, so I replaced the electrolyte with a polymer capacitor that was lying around. I also soldered the encoder contacts - many users noticed that without this the button in the encoder did not work (if you paid attention, in the photographs given earlier, you can see that three of the four boards have the encoder's central contact not soldered at all).

The power supply that was sent to me complete with the station had a defect - one of the diodes of the "hot part" was soldered with the wrong polarity, which is why the power mosfet burned out when the soldering station was turned on for the third time and I had to figure out what the reason was, spending another half a day to repair the power supply . It was also lucky that the PWM Controller did not die after the mosfet. This is me to the fact that it may make sense to assemble the block yourself, or use some already proven one.

As a minimal modification of the PSU, small-capacity ceramics from those that were at hand were soldered in parallel to the output electrolytes, and the interwinding capacitor was replaced with a higher-voltage one.

After all the tinkering, it turned out to be a fairly powerful and reliable unit and controller, although clearly more effort was spent than I planned.

Post build setup

There are not so many settings for the station, most of them are configured once.

Directly during the operation of the soldering iron, you can change the temperature adjustment step and perform program temperature calibration - menu items P10 and P11. This is done as follows - press the encoder knob and hold for about 2 seconds, get to point P10, change the order (hundreds, tens, units) by briefly pressing it, change the value by turning the knob, then press again and 2 seconds. hold the encoder knob, the value is saved, and we go to point P11, etc., the next 2s. pressing returns to operating mode.

To get into the advanced program menu, you need to hold down the encoder knob and, without releasing, apply power to the controller.

The most common menu is the following ( short description, default values ​​are given in parentheses):

• P01: ADC reference voltage (2490 mV - TL431 reference)
• P02: NTC setting (32 sec)
• P03: op amp input offset voltage correction (55)
• P04: thermocouple amplifier coefficient (270)
• P05: PID proportional gain pGain (-64)
• P06: PID integration gain iGain (-2)
• P07: PID differentiation factor dGain (-16)
• P08: falling asleep time (3-50 minutes)
• P09:(in some versions - P99) reset tinctures
• P10: temperature setting step
• P11: thermocouple amplifier coefficient

To move between menu items, you need to briefly hold down the encoder button.

The following menu configuration is also sometimes encountered:

• P00: restore default settings (select 1 to restore)
• P01: thermocouple amplifier gain (default 230)
• P02: offset voltage of the thermocouple amplifier, xs what it is, the seller advises not to change without measurements (default value is 100)
• P03: thermocouple °C/mV ratio (default value is 41, it is advised not to change)
• P04: temperature adjustment step (0 locks tip temperature)
• P05: sleep time (0-60 minutes, 0 - disable sleep)
• P06: shutdown time (0-180 minutes, 0 - shutdown function is inactive)
• P07: temperature correction (default +20 degrees)
• P08: wake-up mode (0 - to wake up from sleep, you can rotate the encoder or shake the knob, 1 - you can only wake up from sleep by rotating the encoder)
• P09: something related to the heating mode (measured in degrees)
• P10: time parameter for the previous item (seconds)
• P11: time after which "automatic saving of settings" should work and exit the menu.

It is worth noting that, unlike the board trace, there can be much more firmware options, so there is no single correct description of menu items - there can be many options, even in one version of the board they may differ. Is it possible to advise you to still take models with a text display, and in its absence, look at the recommendations of the seller from whom you bought.

findings

Conditional cons:

1. Out of the box, the temperature of the tip is not necessarily true, I had to tinker with the thermocouple a little to get an acceptable result.
2. For each sting, you have to calibrate the station again. I change the stings not often, for me it is not critical. In addition, some firmware versions have the ability to save multiple profiles, so this minus is not relevant in some cases.

Total: in general, the station works perfectly and I believe that the hemorrhoids with the assembly fully justify themselves. A little later, I will compare several different stations, and there I will describe all the advantages / disadvantages.

That's all, thanks for reading!

Another review of the pen, but with a built-in controller.
Many well-known and inexpensive T12-based DIY soldering station kits have one thing in common - they require a different soldering iron to assemble. Some people, just because of this, completely abandoned the idea of ​​having stations on T12, and the “toad” somehow did not allow paying for already assembled stations. An interesting pen with a built-in controller was found in the open spaces of taobao. It does not require assembly, but is ready to work out of the box. You just need to insert a sting and a laptop power supply.

Appearance

The upper part of the pen has a transparent case through which the internal board is visible. A smooth rubber overlay is put on the place of the grip.

The base of the handle, where the sting is placed, is made of aluminum alloy (as it is written in the seller's lot).

If you expose the place that is covered by the rubber pad, you can see that the metal part is screwed into the plastic body of the pen, but I could not unscrew it.

There is a socket at the top of the handle. 5.5/2.1mm, although laptop power supplies 5.5/2.5mm

The rated power of the soldering iron depends on the supply voltage. According to this picture from the seller, at 19V, the voltage that most laptop PSUs give out, a maximum of 45W can be available.

The handle has a temperature adjustment wheel. Its most extreme positions rest in the range of 200-400C

The middle pin, which touches the body of the sting, is apparently just hanging in the air, although at a minimum, it should go through a 1 MΩ resistor to ground.

Of the main elements used here, a two-channel operational amplifier, stabilizer

P-channel mosfet, to the left of it are two trimmers, to the right of the output is an SMD electrolytic capacitor 25V 10uF

Dimensions and weight
The width of the main part of the handle - 16.1 mm
The width of the handle in place with a rubber pad - 18.2mm
The length of the whole handle - 140.5 mm
External diameter at the inlet - 10.7mm
The inner diameter of the inlet - 5.7mm(sting diameter - 5.4mm - there will be a slight backlash)
Handle weight - 37 grams

Comparison with FX9501 handle

Departure of the sting at the blue handle FX9501 - 4 cm, which makes it very convenient for soldering small electronics, but with access to narrow alleys between highly elevated elements like radiators on motherboards, it was inconvenient. In the monitored handle, the departure is already almost 2 times more - 7.5cm, - therefore, it turns out to be more universal for different conditions.

Hand View Comparison: Viewable vs. FX9501

Operation indication

A two-color red-green LED in the handle is responsible for notifying the status of the soldering iron.

Immediately after power-up and while the temperature is being set, the red LED flashes quickly:

While maintaining the temperature, the red diode blinks less frequently, the wattmeter readings periodically fluctuate between 8.5-16W. The slider here is set to 300g.

If the wheel is turned in the direction of decreasing temperature (counterclockwise), the red LED will stop flashing, the green one will remain on:

Tests

Correspondence of temperatures to the indicated values ​​on the adjusting dial
Power supply - laptop PSU 19V, 3.42A. Sting - BC (M) 3 9 Ohm.
From the tests it can be seen that the actual temperature is up to the established 300g. goes into plus by 70-80 degrees, then with the rotation of the wheel in the direction of increasing temperature, the difference decreases.

200g (wheel) - 269g (thermocouple)

250g (wheel) - 329g (thermocouple)

300g (wheel) - 367g (thermocouple)

350g (wheel) - 410g (thermocouple)

400gr. (wheel) - 430gr. (thermocouple)

Immersion of the stinger in water
In a calm state, the consumption of a soldering iron is 8-15W

When immersed in water, consumption increases to 48W

Other

Heating rate
From the power supply 19V heating up to 300gr. happens in 14-15 seconds.

Heating in the area of ​​the rubber lining
I did not notice a strong heating, the maximum is a slight heat. BP 19V

Tip scrollability and backlash
It is already harder to rotate the tip in this pen than in the new FX9501 pen, but there is play due to the fact that the entrance hole is slightly wider than the tip. However, the electrical tape pasted here can help out here:

So you can achieve almost perfect fixation of the sting. You can also glue it with a blue tape, because. this place practically does not heat up, but it is too thick and shrinks when the sting is inserted inside, so I chose a heat-resistant tape because of the thinness.

Quick blade change
Due to the larger overhang, the sting is already done with bare hands without any tweezers and potholders

Power supply from batteries
Hastily assembled 3 18650 lithium batteries in series. I didn’t charge it. Voltage amounted to 11.66V. The soldering iron works at this voltage.

Then I still charged two batteries, a total of 8.4V. Oddly enough, but small things can be completely soldered.

A bag
In Rosegal's 1-cent handbag from the auction of unprecedented generosity, the pen fits perfectly

findings

how hiking option for field work - not bad. The handle is compact and lightweight. Doesn't take up much space in a bag. You can power it from a laptop power supply, a car network or a battery assembly. Well, and most importantly - does not require another soldering iron for assembly. Of course, there are also disadvantages and I will note them: tip backlash, plug backlash in the soldering iron power socket, non-grounded body of the tip, temperature discrepancies indicated on the wheel with real temperatures, but the latter is not so important, because thermal stabilization is more important parameter. In the minuses, I would also write down the complexity of disassembling the handle and its difficult to find at the current moment on popular sites.

The soldering iron was purchased as part of a combined package (1.5kg) through an intermediary, the total price with a $10/50 coupon was $40 + shipping with fees of ~$26.

The product was provided for writing a review by the store. The review is published in accordance with clause 18 of the Site Rules.

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