Aquarium automation. Encyclopedia of radio electronics and electrical engineering

Encyclopedia of radio electronics and electrical engineering / Home, household, hobby

 Comments on the article

In an aquarium, it is necessary to constantly maintain a temperature, light, and oxygen saturation that are favorable for keeping fish. For this, there are technical means - a heater, an illuminator, an aerator. Manual control of them requires daily attention and direct participation of the owner of the aquarium. The automatic machine brought to the attention of readers will save him from many worries, taking over the control of lighting lamps, heating water, air supply, and will even give the inhabitants of the aquarium a portion of dry food once a day. The device has long been used by the author and has been repeatedly repeated by radio amateurs.

The scheme of the aquarium control machine is shown in fig. 1. It consists of a timer that "manages" the operation of the feeder and aerator (chips DD1, DD3 and DD4), a heat stabilizer (DD2.2, DD2.4) and a lighting control unit (DD2.1, DD2.3). The timer turns the aerator on and off at regular intervals with a period of 2 or 4 hours, the feeder works every 24 hours.

(click to enlarge)

When you press the SB1 "Reset" button, the counters of the DD1 and DD3 microcircuits return to their original state: at pins 13 and 14 of DD3 and the outputs of the elements DD4.3 and DD4.4, a low level. Transistors VT7-VT10 are closed, the windings of the short circuit relay and the YA1 feeder electromagnet are de-energized.

The DD1 chip generates at its output M (pin 10) minute pulses, which the DD3 chip counts. Depending on the position of the SA3 switch, at the output of the DD4.3 element, after 1 or 2 hours, pulses with a frequency of 128 Hz appear for the same time. The voltage obtained as a result of smoothing these pulses by the VD4R19R21C9 circuit opens transistors VT7 and VT9. This leads to the operation of the short circuit relay. As a result, the aerator connected to the XS3 outlet works one hour out of every two (or two hours out of every four). This happens if the SA4 switch is in the lower position according to the diagram. In the neutral position of the switch, the aerator is off, in the upper position it is always on.

20 hours after the meters are set to their initial state, pulses with a frequency of 128 Hz appear at the output of the DD4.4 element. The charging of the capacitor C7 begins with the current flowing through the closed contacts of the switch SA5, the diode VD5, the resistor R20 and the base-emitter sections of the transistors VT8 and VT10. A current flows through the open transistors and the winding of the electromagnet YA1. After about 5 s, when the capacitor C7 is fully charged, the transistors VT8 and VT10 will close, the current in the electromagnet winding will stop. The next time the feeder will work after 24 hours. If you want to feed "out of schedule", the switch SA5 is briefly moved to the upper position according to the scheme, which causes the electromagnet YA1 to operate.

The lighting control and thermal stabilization units are made according to the same schemes. The difference is only in the type of sensing element. In the first case, this is the photoresistor R1, in the second, the thermistor RK1. Therefore, we will consider only the operation of the lighting control unit.

As in previous cases, the automation works if the SA1 switch is in the lower position according to the diagram. In the neutral position, the lamps are off, in the upper position they are always on. When the illumination of the photoresistor R1 is higher than the specified one, its resistance and voltage at the input of the DD2.1 element are small, the logic level at the output of the DD2.1 element is high, at the output of DD2.3 it is low, the transistors VT2 and VT4 are closed, the relay K1 is de-energized, its contacts K1.1 .1 open. The lamps connected to socket XSXNUMX do not light up.

With a decrease in illumination, the resistance of the photoresistor R1 increases. When the voltage at the input of the element DD2.1 reaches a value equal to approximately half the supply voltage, the level at the output of the element DD2.1 becomes low, at the output DD2.3 - high. As a result, transistors VT2 and VT4 open, relay contacts K2.1 close the power supply circuit for lighting lamps. Variable resistor R2 regulate the response threshold.

Since the illumination changes relatively slowly, the DD2.1 element can be in an unstable intermediate state for a long time, which is very sensitive to interference. To suppress interference, capacitor C2 and circuit R7C5 are used.

The power supply unit of the machine consists of a T1 transformer, a VD6 rectifier bridge and an 8 V voltage regulator on a VD7 zener diode and a VT6 transistor. The relay and the electromagnet of the feeder are fed with an unstabilized voltage of 12 V directly from the rectifier.

Diodes VD2, VD3, VD8 and VD9 protect transistors from voltage surges that occur when the circuits of inductive loads are broken - relay and electromagnet windings.

The relay RES32 passport 4.500.341 is used in the machine, which can be replaced by others with a response voltage of not more than 12 V, a response current of not more than 100 mA and contacts that are powerful enough for switching controlled devices. Instead of the photoresistor SF2-4 indicated on the diagram, SF2-1, SF2-2, SF2-9 are suitable. Thermistor - MMT-4. The switches SA1, SA2, SA4, SA5 are three-position P2T, and SA5 is preferably without fixation in the upper position according to the diagram. The overall power of the transformer T1 is at least 15 W, the voltage of the secondary winding is 10 V.

The design of the feeder is shown in Fig. 2.

The plastic tube 3 with an internal diameter of 26 mm and a length of 100 mm is closed from below by a flap 1 and filled with dry fish food. Under the action of an electromagnet 4, the damper 1 opens and food enters the aquarium. After turning off the current, spring 2 returns the damper to its original position. The armature stroke of the electromagnet should be 4 ... 8 mm. In the author's copy, the autostop drive of the IZH-303-Stereo cassette recorder was used. At 12V, it consumes approximately 500mA.

The heating element is made of ten series-connected MLT-2 resistors with a nominal value of 150 Ohm. The resistors are placed in a glass or ceramic tube with an internal diameter of 16 and a length of 300 mm, filled with dry sand and sealed on both sides with rubber stoppers or a compound. Insulated connecting wires are passed through one of the plugs. The power of such a heater - 32 W - is sufficient for a 30 l aquarium. Due to good heat dissipation, the temperature regime of two-watt resistors remains acceptable. If the volume of the aquarium is larger or smaller than indicated, the heater power will have to be adjusted accordingly.

The thermistor RK1 in a similar sealed tube is placed in the aquarium at the maximum distance from the heater. The photoresistor R1 is installed in such a way that its illumination does not change with the switching on and off of the lamps illuminating the aquarium.

After turning on the machine in the network, the LED HL1 flashing at a frequency of 1 Hz indicates the correct operation of the DD1 chip. If there is no blinking, the oscillator on the ZQ1 quartz resonator is probably not excited. Stable generation is achieved by rotating the rotor of the trimmer capacitor C1.

The operation of the aerator and feeder control units is checked by temporarily breaking the circuit connecting pin 10 of the DD1 microcircuit to pin 5 of DD3, and applying to the latter instead of minute second pulses from pin 4 of DD1. As a result, the operation of the machine will speed up by 60 times, the aerator will turn on and off after one or two minutes, and the feeder after 24 minutes. If necessary, by selecting capacitor C7, they achieve the desired duration of switching on the electromagnet of the feeder.

Adjusting the temperature and light controls of the aquarium, variable resistors R2 and R3 set the required thresholds. If the intervals for changing the thresholds are insufficient, replace the resistor R6 or R8. The axis of the variable resistor R3 can be provided with a scale calibrated in temperature values. Graduation is carried out by placing the heater and the thermistor in a separate container filled with water.

Literature

1. Alekseev. The use of microcircuits of the K176 series. - Radio, 1984, No. 5, p. 36.
2. Pilko G. TV camera box heater. - Radio, 1999, No. 2, p. 31.

Author: A.Dubrovsky

See other articles Section Home, household, hobby.

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 Bacteria on nanofiber electrodes could purify wastewater 15.07.2017 Scientists from Cornell University have developed an innovative competitive material for wastewater treatment of contaminants. The new development is based on carbon nanoelectrodes with a conductive coating of 3,4-ethylenedioxythiophene. The electrodes were electrospun from carbon nanofibers and coated with an electrically conductive polymer called PEDOT. After this coating is applied to the electrode, a layer of electrically active Geobacter sulfurreducens bacteria begins to grow on it, which produce an electric current and transfer electrons to the next electrode. Bacteria feed on pollution from sewage and produce electricity, and the conductive nanofiber creates a favorable environment for them. The new material will be able to significantly reduce the cost of producing electrodes and thereby make the water treatment process more accessible. In the future, bacteria sitting on electrodes will be able to capture contaminants directly from the water flowing past them and recycle them. This technology will allow wastewater treatment plants to take up less space and increase productivity. Scientists have created a carbon nanofiber using electrospin and carbonization. The nanofiber becomes visible to the eye after a few hours of electrospin. Carbon nanofiber was used in the development because it has high porosity and is biologically compatible with bacteria. The addition of PEDOT improved the efficiency of the electrode.

Other interesting news:

▪ Environmentally friendly way to burn methane

▪ Electric car charges in 30 minutes

▪ Bose-Einstein condensate drives a phonon laser

▪ Found a mechanism that turns off the feeling of hunger

▪ Magnetic bracelets don't work

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the website Audiotechnics. Article selection

▪ article Lens and glasses. History of invention and production

▪ article Which president promised never to apologize for his country, no matter the facts? Detailed answer

▪ Seidan's article. Legends, cultivation, methods of application

▪ article Powering multi-band Windom with coaxial cable. Encyclopedia of radio electronics and electrical engineering

▪ article Range 88...108 MHz in old receivers. 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