Traditional Chinese Practical Automatic deodorizer: Circuit Design, Parts List & Workshop Prototype Guide

Premium 10,662 credits (=$106.62) · Priced by article length · permanent access after unlock · 1 $ = 100 credits

automatic deodorizerThrough this device, the bathroom can automatically deodorize and delay closing after use, so as to avoid the harm of ozone to the human body and play the role of deodorizing and refreshing air.How it works:Figure 214-1 is a schematic block diagram of the circuit, and the schematic circuit is shown in Figure 214-2. A multivibrator with a frequency of 10KHz is composed of the time base circuit NE555 and R1, R2, C5, etc., and the infrared transmitter is excited through R3 to emit infrared light pulses. The infrared light pulse is reflected by the human body to the receiving tube, and is coupled to the inverting input end of the operational amplifier LM324A1 via C7 and R7. Its gain is set to 100 times by R7 and R8. The amplified signal is sent to the ③ pin of the audio decoding circuit LM567, and its center frequency is adjusted from R9 to 10KHz to be consistent with the infrared emission frequency. In this way, when the signal is received, the ⑧ pin can be changed from the original high level to a low level, and the level change of ⑧ pin is sent to the logic judgment circuit for judgment.Figure 214-1Figure 214-2The logic judgment circuit is mainly composed of three voltage comparators A2, A3 and A4. The positive terminals of A2 and A3 are biased by R16 and R17, and the negative terminal is controlled by the potential of pin 8 of IC3 (LM567). R20~R23 provide bias voltages for the positive and negative input terminals of A4 and are controlled by the output terminals of A2 and A3. When no one is using the bathroom, the receiving tube does not get reflected light, the 8th pin of LM567 is high level, VD6 is in a cut-off state, the negative terminal voltage of A3 is only affected by the bias voltage provided by R10 and R13; the negative terminal of A2 is affected by the delay Due to the influence of capacitor C12, the voltages of the two negative terminals are higher than the positive terminals, so the outputs of A2 and A3 are both low level, VT1 (9013) is cut off, the relay KL does not pull in, the ozone circuit does not work, and the entire circuit is in a waiting state. When there is someone, contrary to the previous situation, the 8th pin of LM567 is low level. C12 is discharged to low level through VD7 and R14; VD6 is turned on, and the negative terminal of A3 also becomes low level; after voltage comparison, the outputs of A2 and A3 are both high level. VD9 and VD10 are turned on and through R19 and R20, the potential of the positive and negative input terminals of A4 is increased, but the negative terminal is still higher than the positive terminal. Therefore, the output is low level and the subsequent control circuit is still in a static state. When the person leaves the bathroom, the 8th pin of LM567 becomes high level again, causing A3 to immediately flip the output to low level. At this time, the delay capacitor C12 on the negative end of A2 starts to charge through VD8 and R15, but it has not yet reached saturation, so the output end of A2 is still high level. This makes the potential of the positive end of A4 higher than the negative end, the output is high level, VT1 is turned on, KL is closed, and the ozone generator works. After 8 minutes, C12 is fully charged and returns to the waiting state. The ozone generator ends its work. At this point, a deodorization process is completed.Figure 214-3 is a block diagram of an ozone generating circuit. It consists of a high-frequency solid-state circuit TWH9222, a dedicated step-up transformer and an ozone generating tube T90. Its working principle is omitted.Figure 214-3Component selection and production:In Figure 214-2, IC1 is the power supply voltage stabilizing integrated circuit LM7809; IC2 can be replaced by the NE555 time base circuit and other types of 555; IC is the audio decoder LM567. A1～A4 are the four operational amplifier unit circuits of LM324 for operational amplifier. VD6~VD11 use 1N4148 type tube. The resistor is a 1/8 carbon film resistor, and R11~R23 should be selected strictly according to the resistance value in the picture. VT1 chooses 9013 with a withstand voltage greater than 25V and a beta value ≥50. The power of the transformer is 3W. The ozone generation circuit uses components from Guangdong Dahua Electronics Factory. You can directly connect TWH9222, step-up transformer and ozone tube T90 with wires without using a circuit board. The electrodes at both ends of the T90 are connected together and used as one electrode; …

Sign in to unlock

Login / Register

One-time payment per article, billed in credits (1 $ = 100 credits). You will review the invoice and the non-refundable digital-asset policy before anything is charged. The PDF is generated on demand and embeds a licensing watermark.