RU2305233C1 - Portable thermostat for biological investigations - Google Patents

Abstract

FIELD: veterinary and medicine.

SUBSTANCE: portable thermostat for biological investigations includes heat insulation housing inside which working chamber is arranged. Access to working chamber is realized through heat-insulated door. Inside working chamber technological floors are arranged; length values of said floors are slightly less than size of inner space of working chamber. Said floors form air ducts. Air passing from working chamber along said floors flows around temperature pickup with the aid of electric fan and it is heated by means of electric heater. Portable thermostat also includes switching unit connected to buses of main power supply; DC amplifier, rectifier, step-down transformer.

EFFECT: simplified design, enhanced operational reliability, lowered consumption of power, material and cost of thermostat.

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Description

The invention relates to veterinary medicine and medicine, in particular to portable thermostats for biological research, and can be used in biological laboratories, in the educational process in higher and secondary educational institutions and as a mini-incubator in the household.

State of the art

Known thermostat containing a housing with an internal capacity and an internal vacuum cavity and a cover with vacuum cavities, which is installed in the upper part of the housing, above its internal capacity, while it is equipped with a hydride-forming substance filled container with a heating element and a temperature sensor with a heat accumulator, in the housing an inlet cavity with an inlet and outlet openings and an external vacuum cavity, wherein the inlet cavity is located between the inner and outer evacuated cavities, and the inside nnyaya container body is connected with the inner cavity evacuated conduit, wherein the sensor with the heat accumulator mounted on the lid on its inner side.

In a thermostat, a temperature sensor with a heat accumulator is made in the form of a housing with an upper stopper with a filler hole in its lower part and with a lower stopper in it, with a working substance inside it, in the form of a first union nut with a movable contact element in its upper part and in the form of a second a union nut with a contact element mounted along its vertical geometric axis by means of an adjustment spring by means of an adjustment spring, the upper part of the housing being connected to the first union nut and through the flexible element to the upper timid, which via a spring connected to the inner walls of the first coupling nut, the movable contact member which is connected at its lower portion to the upper stopper with the upper portion of the first coupling nut connected to a second cap nut.

In the thermostat, a substance is used as the working substance, the melting point of which corresponds to the temperature of thermostating. The thermostat is equipped with a voltage source and a relay, the movable contact element of the first union nut and the contact element of the second union nut are sequentially connected through the power source to the relay control circuit, the contacts of which are aligned with the contacts of the heating element (see US Pat. RF No. 20099622, class N05K 7 / 20, G12B 15/00, published on March 15, 1994).

The disadvantage of this thermostat is the complexity of the design, high manufacturing costs.

Known low-temperature thermostat for storing thermolabile biological material, containing a thermally insulated working chamber with a cooling unit placed in it, divided by shelves in compartments, a temperature sensor, a stationary power supply unit and containers with heat-accumulating substance, while a threshold alarm unit, an electric battery are introduced into it multi-channel switch and n-1 temperature sensors, where n is the number of compartments, while containers with heat-accumulating substance and temperature sensors tours are installed in each compartment, the heat-accumulating substance is selected with the possibility of melting in the temperature range: T _max.dop, T _article ^{± Δ} T, set temperature and stat accuracy, T _article and ^Δ T - the maximum value of the permissible temperature at which biomaterial can be stored, moreover, the outputs of the temperature sensors are connected to the information inputs of the threshold alarm unit and temperature meter via a multi-channel switch, the power supply bus of the thermostat's electrical components is connected to the battery output pa and the outlet of the stationary power supply and the control input of the threshold an alarm unit connected to the output of a stationary power supply. In the thermostat, the multi-channel switch contains a multiplexer, a clock generator, a threshold block, a manual polling control element and a polling mode switch, through which a clock pulse generator is connected to the clock input of the multiplexer, while the first and second control inputs of the polling mode switch are connected respectively to the output of the threshold block and with the element of manual polling control, the information input of the pore block through the switch is connected to the output, which is the output of the multi-channel switch, the input group of which is the group of inputs of the multiplexer.

The thermostat contains an additional temperature sensor located in the tank with the thermophysical equivalent of the stored biomaterial, installed in the working chamber and connected by the output to one of the inputs of the multi-channel switch and with a connector for connecting an automatic temperature recording device.

The thermostat contains a decoupling element connected between the power bus and the output of the stationary power supply.

In the thermostat, the decoupling element is made in the form of a diode (see US Pat. RF No. 2049344, class G05D 23/30, publ. 11/27/1995).

The disadvantage of this thermostat is the design complexity, low reliability, high manufacturing costs.

The closest in technical essence and the achieved positive effect and adopted by the authors for the prototype is a portable thermostat for transporting biological substances, containing a thermally insulated body with a lid and a working chamber, a thermoelectric module, an automatic control unit with a remote control, a radiator, a fan and a ventilation window in a case with a safety grill, characterized in that the working chamber is made of corrosion-resistant metal, the radiator and fan are placed under the bottom of the working chamber, and the lower part of the thermostat housing is equipped with a device including supports for mounting it on the vehicle with a gap to allow air to pass into the ventilation window, and the thermostat cover is equipped with a unit that includes a hatch for connecting with drainage means of donor organs life support (see US Pat. RF №2054608, class F25D 3/14, publ. 02.20.1996).

The disadvantage of this thermostat is the design complexity, the use of expensive components and difficulties in organizing mass production.

Disclosure of invention

The objective of the invention is to develop a simplified design of a portable thermostat for use in biological and chemical laboratories where comparative low-temperature thermostating is required. This portable thermostat can be used in laboratory studies, for example, in determining the activity of enzymes in higher and secondary educational institutions, in determining the biological activity of tissue preparations, as well as in farms as a mini-incubator.

The technical result that can be obtained using the proposed invention is to simplify the device, increase reliability and reduce installed power while reducing material consumption and cost.

The technical result is achieved using a portable thermostat for biological research, containing a thermally insulated housing with a lid and a working chamber, an electric fan located under the bottom of the working chamber, while it is equipped with an electric heater located below the bottom of the chamber, a temperature sensor and switch, a switching unit, buses for mains power supply , a DC amplifier, a power filter, a control unit, a step-down transformer, and the electric fan and electric heater They are connected to the output of the switching unit, the latter is connected to the buses for mains power and the output of the DC amplifier, which is connected to the power filter and the output of the control unit, the inputs of the latter are connected to the sensor and temperature controller and the power filter, the input of which is connected to the output of the rectifier, the input of the rectifier connected to the secondary winding of a step-down transformer, the primary winding of which is connected to the bus power supply, and the working chamber is equipped with technological shelves, the length of which is not How much smaller than the interior of the working chamber, with formation of air channels, wherein the lid is formed as a thermally insulated door.

Brief Description of the Drawings

Figure 1 is a portable thermostat for biological research, a General view.

Figure 2, the same section along aa.

Figure 3 is a structural electrical diagram of stabilization and temperature control.

The implementation of the invention

A portable thermostat for biological research consists of a building 1 with thermal insulation 2, inside of which there is a working chamber 3, accessed through a heat-insulated door 4, inside the working chamber 3 there are technological shelves 5, slightly less than the inner space of the working chamber 3, which form air channels, the air through which the temperature sensor 6 flows from the working chamber 3 due to the electric fan 7 and is heated by the electric heater 8. The latter are connected to the output of the unit switching 9, which is connected to the bus 10 of the main power supply and the output of the DC amplifier 11, which is connected to the power filter 12 and the output of the control unit 13, the inputs of the latter are connected to the sensor 6 and the temperature controller 14 and the power filter 12, the input of which is connected to the output rectifier 15, the input of which is connected to the secondary winding of the step-down transformer 16, the primary winding of which is connected to the busbars 10 of the mains power supply (not shown).

A portable thermostat for biological research works as follows.

When the mains power is connected, the voltage is supplied to the primary winding of the transformer 16 and reduced to the required value, then using the rectifier 15, the reduced voltage is rectified and smoothed by the filter 12. The rectified voltage is supplied to the control unit 13 and the DC amplifier 11. The control unit 13 is a single-level comparator voltage, the output of which the voltage depends on the voltage from the sensor 6 and the setpoint temperature 14 according to the ratio

с датчика 6 уменьшается и согласно соотношению (1) напряжение на выходе блока регулирования 13 увеличивается и, усиливаясь усилителем постоянного тока 11, поступает на блок коммутации 9, который подключает электровентилятор 7 и электронагреватель 8 к шинам 10 сети. Происходит нагрев воздуха внутри рабочей камеры 3. При достижении заданной температуры напряжения

и

будут равны на выходе блока регулирования 13, будет присутствовать нулевое напряжение, следовательно, блок коммутации 9 отключит электровентилятор 7 и электронагреватель 8 от сети, нагрев прекратится.Therefore, when the temperature of the working chamber 3 decreases below a predetermined temperature, the voltage

from the sensor 6 decreases and according to relation (1), the voltage at the output of the control unit 13 increases and, amplified by a DC amplifier 11, enters the switching unit 9, which connects the electric fan 7 and the electric heater 8 to the busbars 10 of the network. The air is heated inside the working chamber 3. When the specified voltage temperature is reached

and

will be equal to the output of the control unit 13, zero voltage will be present, therefore, the switching unit 9 will disconnect the electric fan 7 and the electric heater 8 from the network, heating will stop.

задатчика 14, можно устанавливать различную температуру стабилизации. Точность поддержания температуры рабочей камеры 3 определяется параметрами обратной связи блока регулирования 13.Adjusting voltage

setter 14, it is possible to set different stabilization temperatures. The accuracy of maintaining the temperature of the working chamber 3 is determined by the feedback parameters of the control unit 13.

The invention, in comparison with the prototype and other known technical solutions, has the following advantages:

- increased reliability;

- simplification of structures;

- reduction of installed capacity while reducing material consumption and cost;

- wide functional capabilities, namely the possibility of use in laboratory studies in higher and secondary educational institutions, when determining the biological activity of tissue preparations by yeast dough, as well as in farms as a mini-incubator.

Claims (1)

A portable thermostat for biological research, comprising a thermally insulated body with a cover and a working chamber, an electric fan located under the bottom of the working chamber, characterized in that it is equipped with an electric heater located below the bottom of the chamber, a temperature sensor and a setter, a switching unit, buses for mains power supply, a constant-current amplifier current, power filter, control unit, step-down transformer, and the electric fan and electric heater are connected to the output of the switching unit , the latter is connected to the buses for mains power and the output of the DC amplifier, which is connected to the power filter and the output of the control unit, the inputs of the latter are connected to the temperature sensor and controller and the power filter, the input of which is connected to the output of the rectifier, the input of the rectifier is connected to the secondary winding of the step-down a transformer, the primary winding of which is connected to the busbars of the mains power supply, and the working chamber is equipped with technological shelves, the length of which is slightly less than the internal of the space of the working chamber, with formation of air channels, wherein the lid is formed as a thermally insulated door.

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