Refrigerator automatic deodorizer circuit

Refrigerator automatic deodorizer The traditional refrigerator "deodorizer" uses the porous adsorption of activated carbon to absorb odors in the refrigerator. This kind of deodorizer has no sterilization effect, and requires frequent replacement of activated carbon or the entire finished product, which is very inconvenient to use and increases economic expenditure. Here is an introduction to an electronic deodorizer that can automatically eliminate refrigerator odors. It uses corona discharge to ionize the air, producing a large amount of air negative ions (mainly negative ions) and a certain amount of ozone. After diffusion, it can quickly remove the odor and keep it. The original flavor of food to prevent cross-flavor. Ozone is also a strong oxidant with extremely strong sterilization and disinfection functions, while negative oxygen ions can also inhibit the biochemical processes inside vegetables and fruits and play a certain role in preserving freshness. This electronic deodorizer integrates the functions of deodorization, sterilization, and preservation. It has the characteristics of simple circuit, easy use, and low power consumption (about 1W). Therefore, it is very suitable for amateurs to make and use, and can also be used by small children. Home appliance manufacturer reference. working principle    　　

The device mainly consists of two parts: light control, delay circuit and negative ion generator. The circuit is shown in Figure 1. Use the lighting inside the refrigerator to control the start-up of the device. When the refrigerator is opened to take out food, the light is on, the photoelectric tube VT1 is turned on, the ② pin of the time base circuit IC1 is at low potential momentarily, and the ③ pin immediately outputs a high level, the triac VS is triggered to conduct, and the negative ion generator starts to work. . The working voltage of the light control and delay control circuit is provided by 220V AC power after being stepped down by C1, rectified by VD1, stabilized by VDW and filtered by C2. While the negative ion generator is working, the DC power supply is charged through R2 and capacitor C3. When the voltage across C3 reaches 2/3 of the power supply voltage, pin ③ returns to low level, the thyristor VS is turned off, and the negative ion generator stops working. The charged voltage of C3 is rapidly discharged through the discharge tube in the IC. In this cycle, every time the refrigerator door is opened, the deodorizer will automatically work for 8-10 minutes. Changing the value of R2 can adjust the length of the delay time. The working principle of the negative ion generator circuit is relatively simple. When VS is turned on, the 220V AC power is rectified and current-limited by VD2, VD3, R4, and R5. The one-way pulsating current controls the turn-on and turn-off of VS, causing oscillation. T boost and VD4 rectification generate tens of thousands of volts of negative high voltage, which is discharged into the air to ionize the air and generate negative ions. R6 is a protective resistor designed to prevent electric shock. See the attached table for component selection and production component selection. No. Name Model Quantity R1 Resistor 20K 1 R2 Resistor 1M 1 R3 Resistor 240Ω 1 R4 Resistor 22K 1 R5 Resistor 27K 1 R6 Resistor 2-4M 1 C1, C5 Metallized paper dielectric capacitor 0.1u/400V 2 C2, C3 Electrolytic capacitor 220u/ 25V 2 C4 polyester capacitor 0.01u 1 VD1－VD3 Rectifier diode IN4007 3 VD4 Silicon stack 18kV 1 VDW Zener diode 2CW21H 1 VT1 Phototransistor TLP107 1 VS1 Triac 1A/400V 1 VS2 Unidirectional thyristor 1A/400V 1 IC1 time base IC NE555 1 T self-made switching transformer (see text after the table) 1 Transformer T can be modified with a 35cm black and white TV line output transformer, remove all low-voltage winding coils, and use Φ = 0.35mm enameled wire or silk wrapped wire to wind 28 The turn is L1, and the original high-voltage package is L2. If it is modified with an integrated line output transformer, the whole machine will be smaller in size. The discharge needle is replaced by two thumbtacks. The tip of the thumbtack should be trimmed as sharply as possible with an assorted file to facilitate discharge at the tip. All components can be installed in a plastic box as small as possible, and the AC output line is connected to points A and B of the lighting control circuit in the temperature control box. The whole machine can be placed under the control box, the photoelectric tube is aligned with the lighting in the refrigerator, and the deodorizer can work automatically under the control of the lighting.