This article is the result of an experiment and does not serve as a guide to action. The author does not bear any responsibility for the breakdown of any hardware of your computer, as well as for failures and "glitches" in the operation of any software installed on your computer.

Currently, more and more often you can find a variety of computer accessories on the shelves in online stores and on the market. The Thermaltake Hardcano series of accessories provides a wide range of interface devices as well as control/cooling/etc devices.

Not so long ago I saw Thermaltake Hardcano 7 on the market. What is it? This is an aluminum plug for a 5.25 inch computer bay, on the front panel of which there are connectors for one IEEE1394 port and two USB ports, a three-position slide switch for adjusting the fan speed (L-M-H), as well as a thermometer LCD panel. The thermometer is powered by a coin cell battery. All fasteners and cords are included. This item costs $20. Well, ports in so far as there are not so many users who connect / disconnect digital cameras, scanners, mice via the USB interface every day at home. The speed switch for fans additionally installed in the computer system unit (FanBus) is relevant for overclockers who try to squeeze as many megahertz out of their hardware as possible, and which, in turn, needs more intensive cooling and good air circulation inside the system unit.

Successful technical solutions available for manual manufacturing (at home) can be found much more on English- and Russian-language Internet resources dedicated to this topic, besides not only FanBus, but also RheoBus, etc. But the thermometer is a necessary thing. But paying $20 for a thermometer is not good. And the idea came to my mind without leaving the counter of the stall: to solder the thermometer myself. And better two thermometers - like Thermaltake Hardcano 2, which served as a prototype. But you will have to configure them more carefully, because. discrepancies in the readings of two Thermaltake Hardcano thermometers (ceteris paribus) can be several degrees.

I have been doing radio engineering for a very long time - so I have experience. Within 3 days, about a dozen digital thermometer circuits were reviewed, and, as the most suitable, the thermometer circuit diagram was chosen. Judging by the declared parameters - this is what you need. Yes, and the element base of those times is now publicly available. The article shows a drawing of a printed circuit board, but I did not repeat it - I developed my own. The next day, all the necessary radio components were bought at the radio market (for everything - I spent $ 9 for everything, which is half the price of the prototype) and three printed circuit boards were made: two for two thermometers

third - for LCD panels

View from the side of soldering elements:

And a view from the mounting side of the elements:

Close-up view from the mounting side of the elements:

The process of setting up and testing a thermometer is described in. The only thing I want to draw your attention to is the relationship between atmospheric pressure and the boiling point of water, which strongly depends on the height above sea level. Our thermometers must be set exactly as we're going to measure the temperature of the chips of our "iron friend", not the environment.

I measured atmospheric pressure with a barometer, placing it on a stand near a glass of boiling water at the same level as the surface of the liquid. Atmospheric pressure on my table was 728 mm Hg. B shows the boiling point of water at 100 o C at an atmospheric pressure of 760 mm Hg. We have a significant difference in the two values ​​of atmospheric pressure (as much as 32 mm Hg, which is 1.5 o C). I wonder at what temperature the water will boil in our case? Not at 100 o C - that's for sure.

Having resorted to the help of a mathematical apparatus from the field of molecular physics and thermal physics, I found that at an atmospheric pressure of 728 mm Hg. water boils already at a temperature of 98.28 o C, and calculation by formulas gives the boiling point of water at 100 o C only at atmospheric pressure 775.0934286 mm Hg. An industrial thermometer placed in a glass of boiling water showed 98.4 o C.

To be honest, I trust mathematics more than any. If there is no barometer, then you can find out the value of atmospheric pressure, for example, at the Hydrometeorological Center.

Formulas for calculation look like:

Thus, in the formula (2) we substitute the boiling point of water in degrees Celsius and, the resulting value of T is substituted into the formula (1) . Those. we get the desired pressure P. In order to find out at what temperature water should boil at a given pressure, it is enough to “drive” these two formulas into Excel and, using the temperature selection method, achieve the minimum discrepancy between the current atmospheric pressure (in mm Hg) and calculated.

Our task is to achieve a minimum discrepancy in the readings of two thermometers (ceteris paribus). My discrepancy in the readings was either absent at all, or was 0.1 o C, and this corresponds to the temperature measurement error declared by the author in the middle of the temperature range. The entire range of measured temperatures is -60 ... +100 o C. In fact, the thermometer is able to measure the temperature of both "hot" and "cold" objects.

My thermometers easily measured the temperature of the soldering tip during heating and showed 175 o C. The temperature of the “warmed up” vapors of liquid nitrogen was almost as easily measured - it was -78 o C (control measurements were carried out in parallel using a thermocouple at the same point with a temperature sensor ), although the temperature of liquid nitrogen itself is -190 o C, I still did not dare to dip the temperature sensor into the liquid because of the threat of its destruction and, as a result, a small local boiling of liquid nitrogen with the release of drops (otherwise it would be like in the movie " Terminator-2":-).

As you can see, the range of measured temperatures is to some extent determined by the type of temperature sensor used, but there are also limitations in the range laid down in the circuit diagram of the thermometer: it is actually possible to measure temperatures in the range from -100 o C to +199.9 o C with the appropriate temperature sensor such as thermocouples. But when using a thermocouple, it will be necessary to significantly modify the circuit diagram of the thermometer.

To install the thermometer boards, I used a metal chassis from a damaged CD-ROM drive.

Attached to the front of the chassis is an empty blank from your system unit with dremel-cut windows for LCD panels, on which a printed circuit board with soldered LCD panels is pre-installed.

As height limiters (racks), polyethylene bushings of filters from "West" cigarettes were used.

On the plug, to which a printed circuit board with LCD panels is attached with screws, a bezel with machined recesses on the inside for the screw heads is attached. I used dichloroethane adhesive to attach the bezel.

The false panel may not be manufactured if the LCD panels are fastened to the plug using plastic racks attached to the plug from the inside with some kind of glue, for example, based on the same dichloroethane. The printed circuit boards of the thermometers are attached directly to the chassis on brass posts.

Power is supplied to one of the thermometer boards by means of a MOLEX adapter "male - two females", in which the power leads from one "mother" are soldered directly to the printed circuit board.

To power the thermometers, 12V leads are used. To obtain a supply voltage of 9V, a KREN9A stabilizer was used. If you want the temperature to be displayed even when the computer is powered off, you can connect a Krona battery through a diode.

The thermal sensors that I used in my design are different from those used by the author. And, as a result, I had to recalculate the resistance of resistors in voltage dividers. The recalculated resistor values ​​differ significantly from the values ​​shown in the circuit diagram.

Temperature sensors are mounted anywhere you want. The simplest device for fastening temperature sensors is to press the temperature sensor with a wooden clothespin, but it needs to be significantly improved. To fasten the temperature sensors, I used a piece of cylindrical ebonite with a diameter of 16 mm with a round hole drilled perpendicular to the longitudinal axis of symmetry for the radius of the thermistor. Along the longitudinal axis of symmetry, a groove was also machined by a dremel for mounting the sensor from the end of the printed circuit boards. This ensures maximum ease of installation on a RAM bar...

and on VideoRAM...

from the end of the printed circuit board of the video card, as well as a snug fit of the temperature sensor to the microcircuit (when using a clothespin, the clamping force is noticeably higher, so look - do not overdo it - you can crush the temperature sensor in this way) and secure fastening of the entire system as a whole.

The clamp for attaching the sensor to the video card (I have a Radeon 9100 noname) has one "tooth" cut off. on my video card, video memory chips are installed in "fading" cases, and on the reverse side, under the chips, a lot of unpackaged trifles are soldered.

Your memory can be in BGA packages, and mirrored on both sides of the printed circuit board. In this case, a thickness of 16 mm may not be enough.

To mount the sensor on the RAM bar, I used a symmetrical clamp. The RAM memory bar with a fixed temperature sensor is shown in the photo:

Another option for attaching a temperature sensor is office "crocodiles", which fasten a thick stack of pages of various formats. In this case, you will have to lay a solid, thin dielectric between the bottom of the clamp and the printed circuit board of the video card in order to avoid failure of the latter.

Plastics for the manufacture of clamps are not suitable, because. we need that periodic heating / cooling does not lead to a change in the linear dimensions of the temperature sensor clamp. You can, of course, use caprolon (also a dielectric), but this is a very hard material and its processing is very laborious. The width of the inner groove, sawn along the longitudinal axis of symmetry of the clamp, should be chosen practically - the application of little effort when "putting" the clamp on the memory bar can cost a lot due to the scanty difference in the height of mounting memory chips on the bar in 0.055 mm.

The most convenient way is to fasten the temperature sensor between the fins of the radiators for cooling chipsets of motherboards, video cards, etc.

Now that everything is set up properly and everything works, you can see that at stock frequencies (250/250) the VideoRAM temperature is 31.7 o C, and at higher frequencies (300/285) the VideoRAM temperature is 38.3 o C when running 3DMark2001SE /1024x768x32/ . Temperature RAM /Mtec 256Mb/ 40.4 o C and 49 o C, respectively.

The indicator on the left shows the temperature of the VideoRAM, the indicator on the right shows the temperature of the operational RAM about a minute after the computer is turned on.

Literature:

1. V. Suetin, Radio No. 10, 1991, p. 28 (http://m33gus.narod.ru/G_RADIO/1991/10/og199110.html)
2. A.S. Enohovich, M., Enlightenment, Handbook of Physics and Technology, 1989, p.115

Good luck with your modding.

Apranich Sergey aka Pryanick

[email protected]

This article will help in creating a simple and at the same time reliable thermal control device for "heating" equipment (amplifiers, power supplies and any parts using radiators)
The principle of operation is simple ... the thermistor is pressed against the radiator with thermal paste and a bracket, the maximum allowable temperature is set, and as soon as the radiator heats up to this temperature, the fan turns on and cools the radiator until the temperature drops on the thermistor.
An excellent solution for cooling the amplifier, because if you listen to music at a low volume, fan cooling is not necessary, there is no need to create unnecessary noise. And as soon as the amplifier runs at high power and the radiator heats up to the maximum allowable temperature, the fan will turn on. The maximum allowable temperature is set either "by touch" or with a thermometer. In my case, the "touch" method was enough.

Scheme:

A photo:

And now according to the scheme. The trimming resistor adjusts the fan threshold. Thermistor of Soviet origin, worth a penny:

The operational amplifier LM324 (4-channel op-amp) can be replaced with an LM358 (two-channel op-amp) you will win in size .. but they do not differ in price ... The fan is a regular computer fan at 12V ... The transistor can be replaced with any similar structure. There is nothing more to add...

Printed circuit board four-channel, transistors are replaced by more powerful BC639, I don’t answer stupid questions “why the board doesn’t match the diagram”:

Mounting option for radiator.

Hello)
Today from me is a review of a good soldering iron with temperature control.
Who cares - welcome under cat.
And there is disassembly, measurements and a little refinement ...
Soldering iron provided for review, item 18…

Soldering iron specifications:

Power: 40W
Temperature: 200...450°C
Input voltage: 220...240V
Length: 250mm

Delivery set, appearance.

Supplied in a blister, except for a soldering iron, there is nothing in the kit.


A couple of additional stings of various types would not hurt very much ...

Similar in size to Gj-907


The temperature regulator is smaller, located closer to the wire, which is much more convenient. In the 907, it is larger and is located right in the grip zone of the handle, often accidentally knocked off.

Wire length 140 cm, at the end of the "enemy" plug.


The wire itself is thick, hard and heavy. Exactly like from the system manager. Reliability is certainly good, but not in this case.


Under the outer insulation - 3 cores, the grounding of the sting is used "straight from the outlet". For comparison, in the 907th, the wire is two-wire, grounding must be separately hooked with a crocodile.


I replaced the plug, and indeed, for a person who buys a soldering iron, this procedure is not difficult. Later I will find a suitable wire - I will replace it, it will be much more convenient to work with a thinner one.

Sting, heating element

The tip of the soldering iron is removable, non-flammable.


On the product page, there is a sharp conical tip, and I received a soldering iron with a similar one to 2CR from this picture



Personally, it is more convenient for me to use such a sting when soldering output components, wires than a sharp one. Moreover, I have a soldering iron with a sharp one. Who needs a sting exactly the same as in the picture of the store - keep this in mind.


The tip of the tip is well magnetized, and the part where the heater enters is very weak.
Under fireproof coating - copper (sharpened a little with a file)

It is easy to change, you need to unscrew the casing.


Heating element - nichrome in a ceramic tube


Diameter - 5.2 mm, length - 73 mm.


There are 4 wires coming out of the heater - 2 wires for the heating element and 2 wires for the temperature sensor. Heating element resistance 950 Ohm (two white wires).




The sting "sits" to the end, the restrictive sleeve during installation does not lift it above the tip of the heater.

The inner diameter of the tip is 5.5 mm, and that of the heater is 5.2 mm, i.e. there is a gap.
In principle, the soldering iron works out of the box, but after an hour or two of work, I examined the heater and found the place of contact with the tip.


The air gap clearly does not contribute to the transfer of heat to the sting.
So I wrapped 3 layers of thin aluminum foil for a tighter fit.

The completion is extremely simple and effective, it takes just a couple of minutes. Subsequent measurements were already taken with her.

Thermal control board

Judging by the board and 4 wires from the heater, thermocouple feedback is implemented here, and not just an adjustment of the power supplied to the heater. Those. it must maintain exactly the set temperature, and not the heater power, which we will check later.

The element base is very similar to the CT-96, which has proven itself among inexpensive soldering irons.
Operational amplifier

Triac for heater control

There is a trimmer on the board for more precise temperature control, but I didn’t touch it, I didn’t have to)
In terms of maintainability, the soldering iron is good, there are no scarce parts, there are no parts in SMD cases either. In the event of failure, you can easily replace the burnt part.

Temperature measurement

So we got to the most important part of the review.
A few words about the method of measurement.
There are specialized devices for such purposes, but unfortunately I don’t have one.


But then there is an ordinary non-contact thermometer, also known as a pyrometer. It is not entirely suitable, of course, for such measurements, because lies very strongly on shiny metal surfaces and the measurement spot is much larger than the tip of the sting.
I tried to remove the stinger cover and painted the thick part of the stinger with a marker. But even this was not enough, it was still narrower than the sensor holes. The values ​​were approximately 40 percent lower.
Then I had to move my convolutions and figure out how to make him measure the temperature of the sting. I didn’t think of anything better than how to cut a small circle out of foil (according to the diameter of the hole in the pyrometer, it would be too big for a radiator), and paint it with a black nitro marker. Then he put it on the thick part of the sting and slightly rounded it along the radius of the sting (for a larger contact area and better thermal conductivity). That's what happened


During heating, the red LED lights up, when the set value is reached, it goes out.
The warm-up time from room temperature to the set temperature of 200°C is about one minute.
To begin with, I set it to 200 degrees, waited until the foil warmed up well, then measured it.
I apologize in advance for the photo, because the values ​​​​on the pyrometer last a couple of seconds, you need to have time to bring it to the soldering iron and focus the camera.



Now 250°C



and 300°C

As you can see, the soldering iron from the factory is perfectly calibrated (I didn’t even touch the trimmer) and also keeps the set temperature perfectly! Moreover, the results were obtained from the 1st time, I set the temperature, waited, measured, photographed. Then the next value, and so on. To be honest, I did not expect for such a price ... pleasantly surprised. Reading reviews of similar soldering irons assembled from almost the same components, I was ready for overheating, underheating, deviations from the set temperature by 30-50 degrees and calibration with a tuning resistor. But none of this happened, and there was no need to do so.
But, I repeat, the measurements were already carried out with foil on the heater, which improves heat transfer between the tip and the heater.

Conclusion:

I will be brief, everything is already detailed in the review.
Quite a good soldering iron, with honest temperature control, well calibrated from the factory. I also liked working with a complete sting and the location of the regulator. Another advantage is high maintainability.
However, for more comfortable work with the plug, it is advisable to replace the hard wire, as well as to carry out an extremely simple revision in the form of winding foil on the heater.

P.S. the question of additional stings remains open, I suspect that they will fit here

We control the cooler (thermal control of fans in practice)

For those who use a computer every day (and especially every night), the idea of ​​Silent PC is very close. Many publications are devoted to this topic, but today the problem of computer noise is far from being solved. One of the main sources of noise in a computer is the CPU cooler.

When using software cooling tools such as CpuIdle, Waterfall and others, or when working in Windows NT/2000/XP and Windows 98SE operating systems, the average processor temperature in Idle mode drops significantly. However, the cooler fan does not know this and continues to work at full speed with the maximum noise level. Of course, there are special utilities (SpeedFan, for example) that can control fan speed. However, such programs do not work on all motherboards. But even if they work, it can be said that it is not very reasonable. So, at the stage of computer boot, even with a relatively cold processor, the fan runs at its maximum speed.

The way out is really simple: to control the speed of the fan impeller, you can build an analog controller with a separate temperature sensor attached to the cooler radiator. Generally speaking, there are countless circuit solutions for such temperature controllers. But two of the simplest thermal control schemes deserve our attention, which we will now deal with.

Description

If the cooler does not have a tachometer output (or this output is simply not used), you can build the simplest circuit that contains the minimum number of parts (Fig. 1).

Rice. 1. Schematic diagram of the first version of the thermostat

Since the time of the "fours" a regulator assembled according to such a scheme has been used. It is built on the basis of the LM311 comparator chip (the domestic analogue is KR554CA3). Despite the fact that a comparator is used, the regulator provides linear rather than key regulation. A reasonable question may arise: "How did it happen that a comparator is used for linear regulation, and not an operational amplifier?". Well, there are several reasons for this. Firstly, this comparator has a relatively powerful open-collector output, which allows you to connect a fan to it without additional transistors. Secondly, due to the fact that the input stage is built on p-n-p transistors, which are connected according to a common collector circuit, even with a unipolar supply, it is possible to work with low input voltages that are practically at ground potential. So, when using a diode as a temperature sensor, you need to work at input potentials of only 0.7 V, which most operational amplifiers do not allow. Thirdly, any comparator can be covered with negative feedback, then it will work the way operational amplifiers work (by the way, this is the inclusion that was used).

Diodes are often used as a temperature sensor. A silicon diode p-n junction has a voltage temperature coefficient of about -2.3 mV / ° C, and a forward voltage drop of about 0.7 V. Most diodes have a housing that is completely unsuitable for mounting them on a heatsink. At the same time, some transistors are specially adapted for this. One of these are domestic transistors KT814 and KT815. If such a transistor is screwed to a heatsink, the collector of the transistor will be electrically connected to it. To avoid trouble, in a circuit where this transistor is used, the collector must be grounded. Based on this, our temperature sensor needs a p-n-p transistor, for example, KT814.

You can, of course, just use one of the transistor junctions as a diode. But here we can be smart and act more cunningly :) The fact is that the temperature coefficient of the diode is relatively low, and it is quite difficult to measure small voltage changes. Here intervene and noise, and interference, and instability of the supply voltage. Therefore, often, in order to increase the temperature coefficient of the temperature sensor, a chain of diodes connected in series is used. In such a circuit, the temperature coefficient and forward voltage drop increase in proportion to the number of diodes turned on. But we don’t have a diode, but a whole transistor! Indeed, by adding only two resistors, it is possible to build a two-terminal transistor on a transistor, the behavior of which will be equivalent to the behavior of a string of diodes. What is done in the described thermostat.

The temperature coefficient of such a sensor is determined by the ratio of resistors R2 and R3 and is equal to T cvd *(R3/R2+1), where T cvd is the temperature coefficient of one p-n junction. It is impossible to increase the ratio of resistors to infinity, since along with the temperature coefficient, the direct voltage drop also grows, which can easily reach the supply voltage, and then the circuit will no longer work. In the described controller, the temperature coefficient is chosen to be approximately -20 mV / ° C, while the forward voltage drop is about 6 V.

The temperature sensor VT1R2R3 is included in the measuring bridge, which is formed by resistors R1, R4, R5, R6. The bridge is powered by a parametric voltage regulator VD1R7. The need to use a stabilizer is due to the fact that the +12 V supply voltage inside the computer is rather unstable (in a switching power supply, only group stabilization of the output levels of +5 V and +12 V is carried out).

The unbalance voltage of the measuring bridge is applied to the inputs of the comparator, which is used in linear mode due to the action of negative feedback. The tuning resistor R5 allows you to shift the control characteristic, and changing the value of the feedback resistor R8 allows you to change its slope. Capacitances C1 and C2 ensure the stability of the regulator.

The regulator is mounted on a breadboard, which is a piece of one-sided foil fiberglass (Fig. 2).

Rice. 2. Wiring diagram of the first version of the thermostat

To reduce the dimensions of the board, it is desirable to use SMD elements. Although, in principle, you can get by with ordinary elements. The board is fixed on the cooler radiator with the help of the transistor VT1 fastening screw. To do this, a hole should be made in the radiator, in which it is desirable to cut the M3 thread. In extreme cases, you can use a screw and nut. When choosing a place on the heatsink to secure the board, you need to take care of the availability of the trimmer when the heatsink is inside the computer. In this way, you can attach the board only to radiators of the "classic" design, but attaching it to cylindrical radiators (for example, like Orbs) can cause problems. Good thermal contact with the heatsink should only have a thermal sensor transistor. Therefore, if the entire board does not fit on the radiator, you can limit yourself to installing one transistor on it, which in this case is connected to the board with wires. The board itself can be placed in any convenient place. It is not difficult to fix the transistor on the radiator, you can even simply insert it between the fins, providing thermal contact with the help of heat-conducting paste. Another method of fastening is the use of glue with good thermal conductivity.

When installing the temperature sensor transistor on a radiator, the latter is connected to ground. But in practice, this does not cause any particular difficulties, at least in systems with Celeron and PentiumIII processors (the part of their crystal that is in contact with the heatsink has no electrical conductivity).

Electrically, the board is included in the gap of the fan wires. If desired, you can even install connectors so as not to cut the wires. A correctly assembled circuit requires practically no tuning: you only need to set the required fan impeller speed corresponding to the current temperature with a trimming resistor R5. In practice, each particular fan has a minimum supply voltage at which the impeller starts to rotate. By adjusting the regulator, it is possible to achieve fan rotation at the lowest possible speed at a radiator temperature, say, close to ambient. However, given that the thermal resistance of different heatsinks is very different, it may be necessary to correct the slope of the control characteristic. The slope of the characteristic is set by the value of the resistor R8. The value of the resistor can range from 100 K to 1 M. The larger this value, the lower the temperature of the radiator, the fan will reach maximum speed. In practice, very often the processor load is a few percent. This is observed, for example, when working in text editors. When using a software cooler at such times, the fan can operate at a significantly reduced speed. This is exactly what the regulator should provide. However, as the processor load increases, its temperature rises, and the regulator must gradually increase the fan supply voltage to the maximum, preventing the processor from overheating. The heatsink temperature when full fan speed is reached should not be very high. It is difficult to give specific recommendations, but at least this temperature should "lag behind" by 5 - 10 degrees from the critical one, when the stability of the system is already violated.

Yes, one more thing. It is desirable to make the first switching on of the circuit from any external power source. Otherwise, if there is a short circuit in the circuit, connecting the circuit to the motherboard connector may cause damage to it.

Now the second version of the scheme. If the fan is equipped with a tachometer, then it is no longer possible to include a control transistor in the "ground" wire of the fan. Therefore, the internal transistor of the comparator is not suitable here. In this case, an additional transistor is required, which will regulate the +12 V fan circuit. In principle, it was possible to simply modify the circuit on the comparator a little, but for a change, a circuit assembled on transistors was made, which turned out to be even smaller in volume (Fig. 3).

Rice. 3. Schematic diagram of the second version of the thermostat

Since the whole board placed on the radiator heats up, it is rather difficult to predict the behavior of the transistor circuit. Therefore, it took a preliminary simulation of the circuit using the PSpice package. The simulation result is shown in fig. 4.

Rice. 4. The result of circuit simulation in the PSpice package

As you can see from the figure, the fan supply voltage increases linearly from 4V at 25°C to 12V at 58°C. This behavior of the regulator, in general, meets our requirements, and at this point the modeling stage was completed.

Schematic diagrams of these two versions of the thermostat have much in common. In particular, the temperature sensor and the measuring bridge are completely identical. The only difference is the bridge unbalance voltage amplifier. In the second version, this voltage is supplied to the cascade on the transistor VT2. The base of the transistor is the inverting input of the amplifier, and the emitter is the non-inverting input. Next, the signal goes to the second amplifying stage on the transistor VT3, then to the output stage on the transistor VT4. The purpose of the containers is the same as in the first variant. Well, the wiring diagram of the regulator is shown in Fig. 5.

Rice. 5. Wiring diagram of the second version of the thermostat

The design is similar to the first option, except that the board has a slightly smaller size. You can use ordinary (not SMD) elements in the circuit, and any low-power transistors, since the current consumed by the fans usually does not exceed 100 mA. I note that this circuit can also be used to control fans with a large current consumption, but in this case, the VT4 transistor must be replaced with a more powerful one. As for the tachometer output, the TG tachogenerator signal directly passes through the regulator board and enters the motherboard connector. The procedure for setting the second version of the regulator is no different from the method given for the first version. Only in this variant, the setting is made by the tuning resistor R7, and the slope of the characteristic is set by the value of the resistor R12.

findings

The practical use of the thermostat (together with software cooling tools) showed its high efficiency in terms of reducing the noise produced by the cooler. However, the cooler itself must be efficient enough. For example, in a system with a Celeron566 processor running at 850 MHz, the boxed cooler no longer provided sufficient cooling efficiency, so even with an average processor load, the regulator raised the cooler supply voltage to the maximum value. The situation was corrected after the replacement of the fan with a more efficient one, with an increased diameter of the blades. Now the fan gains full speed only when the processor is running for a long time with almost 100% load.