WITH IRON — ON APIARY

Going to put the hives in your apiary improvised electronic thermostat — you will not regret. Because it is simple, in General, the device will create for bee colonies conditions, like the comfort, the economic feasibility of which has been repeatedly pointed out, and the magazine “modelist-Konstruktor” (see for example, №10’93, 12’96, 1’2000). The use of a controller leads to decrease almost two times the previous costs feed — sugar or honey because the bees do not have to spend energy to maintain the desired temperature.

Rules for the use of the proposed design for spectroheliograph hives (with automatic temperature regulation in the course of the year) simple and boil down, essentially, to install the optimum temperature (measure it in the area of the lower straps electronic thermometer). Taking into account the physiological characteristics of bees this setting in the spring and summer should be in the range 25 to 27 °C.

 

In September the temperature is gradually lowered, leading to 20 ”C. the disappearance of brood in the hive installed 9— 12 “C. In October, the optimum temperature of 8 °C. And with approach of steady frosts, when the outdoor thermometer shows -8 to -20 °C in the hive to support only 0.4 °C.

 

The beekeeper must remember that the temperature difference under the cushions and on the bottom of the hive (estronom space) is recommended to maintain in the range of 7-10 °C. for Example, if at the time of spring cleansing flight the temperature under the pillow reached 30 °C, at the bottom of the hive (under the framework) it should be 20-22 °C. This will allow the bees to warm their nests with much less surgey to go by the time spring cleaning flyby viable, with large areas of brood and to create a strong family — the key to a successful honey crop.

The proposed device is multichannel, and all channels are absolutely identical, and their number is determined by the amount of the heated hives. For example, channel a dozen for mobile pavilion 12 bee colonies. Then feed the transformer T1 is taken a power of 500 watts. And as the diodes VD10—VD17 can be easily calculated for a current of 10 A and a voltage below 50 V.

 

The need for galvanic isolation from the network (and lower the voltage to 40 V) is dictated by the safety requirements, as well as the fact that the low voltage inhibit bees and not cause their aggressiveness. In extreme cases, the electronic thermostat can be powered from a car battery by disconnecting the T1 and rectifiers connecting the terminal “+12 V” to the points “B” and “C”, and “-12 V” grounding.

 

Now about the heating elements. You can use Nickel-chromium spiral of iron (electric) laid in tracks-snake, executed in plaster or alabaster (one for each channel) castings, bordered laterally straps, and the bottom covered with plywood. On top of this casting is placed the metal sheet, which is attached to an electric thermostat from the old iron (on each channel) set the minimum temperature of operation is 70 °C.

 

The lower part of the hive (electrical connections not shown):

 

1,4 — front and rear compound wall insulated wooden hives; 2 — textolite Board termoatonomo; 3 — frame; 5 — connector; 6 — internal wall of the hive; 7 — uruguy thermostat; 8 — plywood box; 9 — the bottom of the hive; 10 — pallet (box s1); 11 — terminal; 12 — nichrome spiral heater; 13 — alabaster casting (140x140x20); 14 — cover (steel sheet 170×170,51,5)

 

If not at hand will be the required number (one for each channel) UTY-trading of thermostats, as protection against overheating, you can apply fire sensors wood, designed for a temperature of 72 °C. Or to make them of elastic bronze (brass) plates glued using textolite gasket glue BF-2. The free ends of the plates are compressed and soldered with wood’s alloy (lead, bismuth, cadmium and tin), and the sensor is attached by a bolt to the metal plate of the heater.

 

Heaters can also serve as a conventional 220-volt bulbs. But keep in mind that at a voltage of 40 In their power drops six times. The desired number of lamps is placed in cans with river sand. And the sensors are attached to the buildings of the cans.

 

However, the easiest way as a heater to use the base (heel) with factory iron bimetal thermostat. Just do not forget that if the capacity of the iron At 220 was 1000 W, at 40 it will drop to 30 to 37 watts.

Momentary loss of electric power (for example, when triggered sensors) does not threaten loss of bees. Indeed, due to the high heat capacity, low thermal conductivity of honeycombs and honey temperature in the hive even after disconnecting the power circuit is held long enough for the redistribution of bees in each club.

 

Moreover, the continued inclusion of the heater is not allowed. Immediately triggered protection at an appropriate temperature sensor. Then instantly opens the power circuit of the thyristor VS1.

 

Capacitor C2 immediately begins to discharge through the resistance R7. The VT2 transistor will be closed and will open VТЗ (VT2 will cease to shunt). The result will light up the led VD2 (АЛ307) showing on the remote, which channel (the hive) have any disorder. Through the diode VDЗ opens the transistor VТ4, triggering a call-bell (alarm clock “Slava-5338”). And on the remote audible and visual signals will disturb the beekeeper as long as it does not fix the problems.

 

On a single chip DD1 collected three channel electronic thermostat. Look at the one of them first. The element DD1.1 performs here the function of the comparator with a threshold of 0.5 Usup; DD1.2 — the buffer providing the desired nature of the feedback loop temperature control.

 

Schematic diagram of multi-channel electronic thermostat for apiary

 

In the initial state (when the temperature is greater than the threshold) the resistance of the thermistor RK1 little. And at the entrance of DD1.1 voltage above switching threshold. And this means that the output of this element is low and the output DD1.2 — high, the Transistor VT1 is open and shunts managing the transition of SCR VS1. Therefore, the latter is locked, and the heater is disabled.

 

As the temperature decreases the resistance of the thermistor increases. Means of achieving the selected temperature the element DD1.1 definitely will switch. The high level voltage transfer DD1.2 to another state that closes transistor VT1. Then the current flowing through the resistor R5, open SCR VS1 and the heater will turn on.

 

With increasing temperature in the hive the resistance of the thermistor will decrease and there will come a time when the heater will turn off.

 

The temperature accuracy when using 10-Kopaonik RTDs of the series of KMT and MMT is about 1 °C. When using RTDs with a different resistance will have to change R1, R2 (and corresponding resistors in the other channels). And so that the sum of the values of R1 and R2 (with an average position of the engine “podstroechnye”) was approximately equal to the resistance of the thermistor at the operating temperature.

 

Rigged resistors provide a temperature scale. Graduate of her, placing the thermistor in a container of water on a hotplate. Temperature controlled by mercury thermometer.

 

To control the switching of SCR instead of a heater used in a table lamp. Rotating the handle of the corresponding “podstroechnye”, to achieve the switching of the thermostat. On a scale applied to the specific temperature. After calibrating all the sensors connect with the rest of the instrument shielded wire and placed in the hive below the frames.

 

In conclusion, on the elemental basis. All “trimmers” — SPZ-16, the other resistors — MLT. The SCR in each of the channels should open at the control current of 4 mA. When using semiconductor devices КУ201В (G, D, E) or КУ202В (G, D, E) with an operating voltage more than 50 V as the diodes VD10—VD17 acceptable Д242 or any other with a reverse voltage less than 50 V.

 

But when replacing thyristors on Simes-type Torah КУ208 you can do without diodes VD10—VD17, sapita heater (at point “B”) from one of the terminals of winding III of the transformer T1 (the second terminal should be connected with “earth”). Moreover, there are power thermostat without transformer (see chart). Then, all thyristors must be designed for a voltage of less than 300 V. This КУ201М (L, N, K), КУ202М (L, N, K). And diodes VD5-VD12 (with the same reverse voltage) are mounted on a finned heatsink with an area of 440 SMG through mica laying.

A. KUKHARENKO, Grodno