Incubator thermostat. Encyclopedia of radio electronics and electrical engineering

Encyclopedia of radio electronics and electrical engineering / Power regulators, thermometers, heat stabilizers

 Comments on the article

Hatching chicks in an incubator is a time-consuming process that requires constant temperature control. The last responsibility is assumed by the proposed thermostat. The author also talks about the design of a simple incubator, gives advice on its use.

The thermostat, the circuit of which is shown in fig. 1 is designed for a small-sized incubator and maintains a temperature set in the range of 20 ... 50 ° C. The thermistor RK1 serves as a sensor, together with resistors R1, R3, R4, R6 forming a measuring bridge. The balance of the bridge at a given temperature is achieved by a variable resistor R6. Capacitors C1 and C3 - noise suppression.

If the temperature is higher than the set temperature, the polarity of the unbalance voltage of the bridge at the input of the comparator DA1 is such that the output transistor of the latter is closed, otherwise it is open. A pulsating voltage is applied to pin 9 of DA1 (the collector of the output transistor) from the output of a half-wave rectifier on diodes VD1 and VD2. The amplitude of its pulses is limited by the Zener diode VD3. At a temperature below the specified pulses from pin 2 of DA1 (the emitter of the output transistor) are fed to the control electrode of the trinistor VS1, opening it in the positive half-cycles of the mains voltage. Resistors R7-R16 connected in parallel serve as a heating element.

The VD4C4 circuit turns the pulsating voltage into a constant one. After the DA2 stabilizer, they feed the measuring bridge and the comparator.

The printed circuit board of the thermostat and the location of parts on it are shown in fig. 2.

The following replacements of elements are possible: comparator K554SAZ (DA1) - to 521SAZ, taking into account differences in the assignment of conclusions, integral stabilizer KR142EN5A (DA2) - to any other with an output voltage of 5 ... 6 V and a load current of at least 50 mA, trinistor KU201K ( VS1) - on KU201L, KU202K-KU202N, diodes KD105 (VD1, VD2, VD4) - on any silicon diodes with a permissible current of 150 ... 300 mA, zener diode D814D (VD3) - on D814G. As RK1, the thermistor ST1-17 is used, its value (resistance at room temperature) can reach 4,7 kOhm, it is only necessary to increase the values ​​​​of the measuring bridge resistors by the appropriate number of times. Variable resistor R6 - SDR-4a. Oxide capacitors - K50-35 or similar. Capacitor C2 - K73-17 for a voltage of at least 400 V

The incubator is a foam box with dimensions of 600x600x300 mm. Holes 6-10 mm in diameter were drilled in its bottom for air access and grooves were squeezed out into which water at a temperature of 43 ° C was poured to maintain the required humidity (during pouring). A metal grate for laying eggs is installed inside, a thermistor RK1 and a heating element from MLT-2 resistors (R7-R16) are placed. It is possible to reduce the inertia of the heater by assembling it from MLT-0,5 resistors. Their number and ratings are selected in such a way that the total resistance remains the same and the permissible power dissipated by one resistor is not exceeded. An ordinary incandescent lamp or a heating element with a power of 20 ... 30 W for a voltage of 110 ... 127V can also serve as a heater.

In the room where the incubator is located, a constant supply of fresh air is required, and the temperature should not go beyond 20 ... 25 ° C. The incubator must not be exposed to direct sunlight. A few hours before laying the eggs, you should turn on the thermostat, use the variable resistor R6 to set the temperature in the incubator to 37,5 ° C and make sure that it has stabilized. For control, an alcohol thermometer is inserted into a specially provided hole in the lid of the incubator. The duration of incubation of eggs of various birds is given in the table.

If the chicks of the first brood hatch a day ahead of time, in the future set the temperature to 0,5 ° C less than that indicated above, if a day later, the same amount more.

Eggs must be fresh, fertile, no more than 15 days old and with an air chamber at the blunt end. Eggs should not be washed or refrigerated. In the incubator, they should lie freely, with a sharp end below the blunt one. It is necessary to turn the eggs three times a day, stopping this procedure only three days before the expected brood. To turn the eggs, you have to open the incubator, after which the temperature regime in it is restored within one to two hours. You should not speed up this process by adjusting the variable resistor R6. Not long before the chicks appear, the eggs are warmed up due to the heat they give off, so the temperature in the incubator should be reduced by 0,5 ° C.

The same thermostat is suitable for home vegetable storage. To change the range of temperatures maintained by it, it is enough to select the value of the resistor R4. The power of the heater must correspond to the volume of the vegetable store.

Author: S.Abramov, Orenburg

See other articles Section Power regulators, thermometers, heat stabilizers.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Machine for thinning flowers in gardens 02.05.2024

In modern agriculture, technological progress is developing aimed at increasing the efficiency of plant care processes. The innovative Florix flower thinning machine was presented in Italy, designed to optimize the harvesting stage. This tool is equipped with mobile arms, allowing it to be easily adapted to the needs of the garden. The operator can adjust the speed of the thin wires by controlling them from the tractor cab using a joystick. This approach significantly increases the efficiency of the flower thinning process, providing the possibility of individual adjustment to the specific conditions of the garden, as well as the variety and type of fruit grown in it. After testing the Florix machine for two years on various types of fruit, the results were very encouraging. Farmers such as Filiberto Montanari, who has used a Florix machine for several years, have reported a significant reduction in the time and labor required to thin flowers. ... >>

Advanced Infrared Microscope 02.05.2024

Microscopes play an important role in scientific research, allowing scientists to delve into structures and processes invisible to the eye. However, various microscopy methods have their limitations, and among them was the limitation of resolution when using the infrared range. But the latest achievements of Japanese researchers from the University of Tokyo open up new prospects for studying the microworld. Scientists from the University of Tokyo have unveiled a new microscope that will revolutionize the capabilities of infrared microscopy. This advanced instrument allows you to see the internal structures of living bacteria with amazing clarity on the nanometer scale. Typically, mid-infrared microscopes are limited by low resolution, but the latest development from Japanese researchers overcomes these limitations. According to scientists, the developed microscope allows creating images with a resolution of up to 120 nanometers, which is 30 times higher than the resolution of traditional microscopes. ... >>

Air trap for insects 01.05.2024

Agriculture is one of the key sectors of the economy, and pest control is an integral part of this process. A team of scientists from the Indian Council of Agricultural Research-Central Potato Research Institute (ICAR-CPRI), Shimla, has come up with an innovative solution to this problem - a wind-powered insect air trap. This device addresses the shortcomings of traditional pest control methods by providing real-time insect population data. The trap is powered entirely by wind energy, making it an environmentally friendly solution that requires no power. Its unique design allows monitoring of both harmful and beneficial insects, providing a complete overview of the population in any agricultural area. “By assessing target pests at the right time, we can take necessary measures to control both pests and diseases,” says Kapil ... >>

Random news from the Archive TOSHIBA SATELLITE laptops can now burn DVD-R/RW 09.03.2003 Toshiba has introduced new laptop models from the Satellite series, positioned as a replacement for desktop PCs. Relatively inexpensive machines are equipped with DVD burners. New items are marked 2455S305 and 1955-S805 and cost respectively 2299 and 2099 US dollars. For this money, the user gets a system on a Pentium 4 processor with 512 MB of memory and a 60-gigabyte hard drive. Other components the same for both machines; NVIDIA GeForce4 420 Go video system with 32 MB video memory, V.92 modem, 10/100 Mbps network adapter from Intel, three USB 2.0 ports and one i Link (IEEE 1394). Notebooks are equipped with DVDR/RW drives. The package also includes Windows XP Home. The differences between the models lie in the larger diagonal of the screen: the Satellite 1955-S805 has 16 inches with a resolution of SXGA (1365x1024) versus 15 inches for the Satellite 2455-S305 with a resolution of 1024x768. In addition, the processor frequency of the first is 2,53 GHz, the second - 2,4 .XNUMX GHz Both models belong to the category of inexpensive notebooks. Previously, DVD burning in Toshiba notebooks was only available on expensive systems such as the Satellite 5205-S703. released in October 2002, the company's first mobile computer with a built-in DVD-R/RW drive. Toshiba's pricing looks better than Apple's other PowerBook offerings, with a 15-inch screen and DVD burner for the same RAM costs $2799 (price from the company's website), and a Sony laptop that also burns DVD sells for $2500 .

Other interesting news:

▪ The main scientific breakthrough of 2018

▪ Salt price

▪ Antibacterial web material

▪ Altruism relieves stress

▪ Genes against gravity

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ radio section of the website. Article selection

▪ article Determination of rectangular coordinates on the map and plotting objects on the map by coordinates. Basics of safe life

▪ How many parts are soccer ball tires made from? Detailed answer

▪ article security guard. Job description

▪ article Improving the electronic voltage stabilizer. Encyclopedia of radio electronics and electrical engineering

▪ article Capacitors. Temperature coefficient of capacitance (TKE). Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

All languages ​​of this page

Arabic	Hebrew	Polish
Bengali	Hindi	Portuguese
Chinese	Italian	Spanish
English	Japanese	Turkish
French	Korean	Ukrainian
German	Malay	Vietnamese

Home page | Library | Articles | Website map | Site Reviews

www.diagram.com.ua
2000-2024