PWM regulator for controlling a car heater. Engine speed regulator for a car heater. Description of the circuit operation

For self-assembly, we offer a proven heater motor speed controller circuit for almost any car.

Schematic diagram of the speed controller

Functions of the stove speed controller

1. Output power regulation. The control method is PWM. PWM frequency - 16 kHz. The number of power stages is 10.
2. Level indication by LEDs.
3. Smooth power change.
4. Storing the installed power.
5. Setting the speed of power change.

Description of the circuit operation

1 . When power is turned on, the last selected power is set. LED_0 indicates the device is ready for operation. LEDs LED_1 - LED_10 display the set fan power.

2 . Change power using the PLUS/MINUS buttons.

3 . Setting the speed of power change.
3.1. Press the PLUS and MINUS buttons simultaneously.
3.2. LED_0 will start flashing. The number of power LEDs turned on corresponds to the selected speed.
3.3. Use the PLUS/MINUS buttons to change the speed.
3.4. To exit the mode, press the PLUS and MINUS buttons simultaneously. LED_0 will stop flashing.

Note: the indication is reversed. The more LEDs turned on, the lower the rate of change in power. The rate of change of power can be recorded when flashing the MK into the EEPROM cell with address 0x00. The number must be no more than 10 (or 0x0A in hex format). If the number is greater, then the default value of 5 is taken.

4 . After ~3 seconds from the last button press, the new settings will be written to non-volatile memory.

Scientists have proposed making microcircuit elements the size of one molecule. Modern silicon electronics has almost reached the limit of miniaturization. The use of organics potentially makes it possible to create microcircuit elements the size of one molecule. Scientists from National Research Nuclear University MEPhI are conducting active research in this area. They recently modeled changes in the excited state of an organic semiconductor molecule. The results of the work were published in the Journal of Physical Chemistry. Organic electronics are considered promising for two reasons. Firstly, the raw materials for organic synthesis are quite accessible. Secondly, the use of organic materials makes it possible to make microcircuit elements the size of one molecule, which brings them closer to the intracellular structures of living objects. Targeted design of organic molecules and functional materials for organic electronics is a promising scientific direction. Scientists summarize existing world experience and engage in predictive modeling. “Our group is engaged in predictive modeling of the properties of materials for organic electronics, specifically for organic light-emitting diodes (OLEDs). When an OLED operates, electrons are supplied from the cathode, holes are supplied from the anode, somewhere in the middle of the device they meet and recombine, and light is emitted. State , when an electron and a hole are nearby, but do not recombine, it can live quite a long time - it is called an exciton, most often this exciton is localized within one molecule,” said one of the authors of the study, an assistant at the Department of Condensed Matter Physics of the National Research Nuclear University MEPhI "and researcher at the Center for Photochemistry of the Russian Academy of Sciences Alexandra Freidzon. According to her, by transferring an exciton to neighboring molecules, it is convenient to control the color and efficiency of the glow of OLEDs: between the layers of n- and p-type organic semiconductors, an emitting layer (usually also a semiconductor) is placed, where electrons and holes meet, recombine and do not “separate” . “We studied the behavior of an exciton in the molecule of a typical hole semiconductor, also used as a matrix of the emitting layer. It turned out that the exciton is localized not on the entire molecule, but on its individual parts, and can migrate throughout the molecule. In particular, it can migrate under the influence of small perturbations - such as the presence of another molecule (for example, an emitter dopant),” said Alexandra Freidzon. The researchers clarified the mechanism and estimated the time it takes for an exciton to migrate from one end of the molecule to the other. “It turned out that along one of the paths migration occurs very quickly, on a picosecond scale – and very specific intramolecular vibrations help it in this,” added an employee of the National Research Nuclear University MEPhI. According to the authors, it is now possible to assess how this process is affected by the presence of neighboring molecules, and to propose modifications to the structure of the original molecule in order to make the process of transferring excitation energy to the emitter molecule as efficient as possible. This is the process of virtual design of functional materials: scientists isolate a key function of a material and build a model of the process underlying that function to determine the main factors influencing the efficiency of the process and propose new modifications to the material. Scientists note that they are now at the first stage of understanding the process of exciton migration in organic semiconductors. Soon they will be able to give recommendations on modifying the molecules used in the matrices of OLED emitting layers. Read more.

This button accordion has been known to everyone for a long time, they just perform it differently. For many this will seem inconvenient, but for me the goal (minimum rework and parts) has been achieved. Owners of cars of the classic VAZ 2101-2107 model know that the control of the rotation speed of the heater motor is useless and are modifying it in every possible way (I saw and installed a nine motor under the hood, although this is probably not news to many). And I decided to keep up with this trend.

My father-in-law's car was damaged.

The resistor highlighted in red is not needed, because I wanted to use it for indication, but did not use it.

Components

It all works as follows: Power is supplied from the switch (J1) to the voltage stabilizer, having previously smoothed out the ripples with a 25V 470 µF condenser (C1), from the stabilizer (DA1) 7805 a 5V voltage powers our controller (DD1 Tiny13). The controller generates PWM with a frequency of 40 KHz (at this frequency it was possible to achieve silent operation of the motor).

The shim is fed through a 100 ohm limiting resistor R2 directly to the Gate of the field switch IRF640 (N channel), the source of the field switch is pulled up to the gate potential by a 1 Kom resistor R3 for reliable closing.

Since the maximum current of the motor is 3A (according to dsh at 5V Gate-Source), the field driver draws a little more than 5A and at a frequency of 40 KHz they do not heat up, which completely satisfies me, so there is no driver in front of the field drivers. Although it is correct that it is needed at least for bipolar patients. And we remove our PWM on the motor from the Field Worker.

The signal to increase and decrease PWM is supplied through the KT817(NPN) transistor switch to the MK port. To protect the field switches from the induction of the motor, a reverse diode was installed (crimped) in front of the motor.

Diode with reverse current 10A.

PWM frequency

You also need a diode as the anode to But in and the cathode at +12V to maintain power.

The device works as follows:

• 1. When turned on for the first time, the motor spins up to maximum speed and decreases to the value that remained after turning off in EPROM, but not lower than 30%. (This was done to be sure that the motor will spin at the minimum duty cycle if condensate is frozen to it (precisely according to This is why my thermostat burned out on the rheostat of the Priora stove) or something similar)).
• 2. By moving the switch to the second position, the PWM duty cycle smoothly increases, as soon as the desired speed is achieved, press the button to the first position and the current duty cycle is saved in the Eprom.

If you need to reduce the PWM, repeat step 2.

A short video.

And who is trying to make an equivalent craft using an analogue, on a 555 timer.

All elements are marked.

The strangest thing is that the frequency is 9.6 MHz/4 = 2.4 MHz. Timer divider 1 = 2.4 MHz. Divider by 8 is disabled in fuses. But often it turned out the same as on the multimeter. The multimeter doesn't lie, I checked it with a generator.