Automatic anti-frost crop controller circuit diagram

The automatic anti-frost crop controller circuit comprises an electric contact mercury thermometer (Q), a control circuit, ignition devices, and other components. The electric contact mercury thermometer features two platinum electrodes; one acts as a contact electrode inserted at the upper part of the thermometer, while the other serves as the control electrode at the desired temperature scale. The monitoring and control temperature is set to +1°C. The control circuit is built around a thyristor (VT), along with resistors (R1, R2) and a capacitor (C). The ignition device includes a small 2.5V lamp (HL) and pyrotechnic material. The assembly involves connecting the two electrodes to the small lamp, grinding a hole in the lamp's glass to inject pyrotechnic material, and wrapping the lamp in plastic film containing approximately 20g of smokable material as an ignition agent. During operation, when the air temperature exceeds the set control temperature (+1°C), the mercury in the thermometer rises above the control electrode, closing the control contacts. This results in the thyristor (VT) turning off due to low gate voltage. Conversely, when the temperature drops and frost conditions develop, the mercury falls below the control electrode, opening the control contacts and triggering the thyristor (VT) to conduct, leading to current flow through the filament of the lamp (HL) and igniting the smokable material. Resistors R1 and R2 should be selected as 1/4W or 1/8W carbon film resistors, while the capacitor (C) must have a voltage rating of 10V or higher. A small toggle switch (S) is used for control, and a small flashlight bulb (HL) rated at 2.5V is selected. Power is supplied by two standard 5V batteries (GB), and the adjustable electric contact mercury thermometer (Q) is employed for temperature measurement.

The automatic anti-frost crop controller circuit is designed to efficiently manage frost conditions that can adversely affect crop growth. The circuit operates by monitoring ambient temperature and activating an ignition mechanism when temperatures drop to critical levels. The electric contact mercury thermometer serves as the primary sensing element, utilizing the expansion and contraction of mercury in response to temperature changes. The dual platinum electrodes enable accurate detection of temperature thresholds, with the control electrode set to a specific value that triggers the ignition sequence.

The control circuit, utilizing a thyristor, allows for rapid switching based on the temperature readings. When the ambient temperature exceeds the defined threshold, the thyristor's gate voltage becomes insufficient to maintain conduction, thereby shutting off the ignition circuit. Conversely, as temperatures fall and approach the frost threshold, the mercury column's descent re-establishes contact between the electrodes, triggering the thyristor to conduct and activate the lamp.

The ignition device is a crucial aspect of the design, incorporating a small lamp and pyrotechnic material to create a controlled ignition source. The assembly process involves careful preparation of the lamp, ensuring that the pyrotechnic material is securely contained and that the ignition agent is adequately protected from premature ignition. The use of a plastic film wrap not only provides structural integrity but also ensures that the smokable material remains contained until the appropriate conditions for ignition are met.

Component selection is vital for the reliability and efficiency of the circuit. The recommended resistors and capacitors must meet specific power ratings to handle the operational conditions without failure. The use of standard batteries for power supply simplifies the design and enhances portability, making it suitable for agricultural applications where access to power may be limited. The adjustable nature of the mercury thermometer allows for flexibility in setting the desired control temperature, accommodating various crop types and environmental conditions.

This circuit exemplifies a practical application of electronic principles in agriculture, showcasing how technology can be harnessed to protect crops from environmental threats, thereby enhancing agricultural productivity and sustainability. Circuit works The automatic anti-frost crop controller circuit consists of electric contact mercury thermometer Q, the control circuit and ignition devices and other components , as shown in FIG. Electric contact mercury thermometer differs and like mercury thermometer is inserted into the cavity of the mercury thermometer, two platinum electrodes New York, is the contact electrode mercury thermometer inserted in the upper part of the warehouse, and the other is inserted in the need to control the temperature scale the control electrode. When using the monitoring and control temperature (fuel smoke temperature) set to + l. The control circuit consists of thyristor VT, resistors Rl, R2 and the capacitor C form. Ignition device consists of a small lamp HL 2.5V and gunpowder, and the like. First leads on the two electrodes small bulbs HL two wires, then fine sandpaper or fine grinding wheel to the top HL glass beads grind a hole, and then from the hole injection into the glass ball have pyrotechnic.

Then the light bulb HL with a suitable sized plastic film wrapping, plastic film built around 20g powder, smokable material as ignition agent. When used, the smokable material is deposited on the formed igniter, the smokable material layer of soil above the pressure to prevent the smokable material fire burning head.

When the air temperature is higher than the temperature measurement and control (+ 1 ), electric contact mercury thermometer Q control contact connected (mercury column rises above the control electrode, the mercury will be connected between the electrode and the contact electrode control), crystal Oh tube VT is extremely low due to the door and turned off. When the temperature drops, atmospheric conditions the formation of frost, the electric contact mercury thermometer Q control contacts are open (the mercury drops below the control electrode, a control electrode and the electrode of the Division turned off), VT due to the gate get high trigger conduction, HL filament current flows in the gunpowder ignited ignition smokable material.

Component selection Rl and R2 use 1/4W or 1/8W carbon film resistors. C selection pressure is IOV over electrolytic capacitors. S use of small toggle switch. HL 2.5V with a small selection of flashlight bulb. GB a choice of two 5th ordinary batteries. Q choose adjustable electric contact mercury thermometer.