Practical Multifunctional Flashlight: Traditional Chinese Circuit Desi

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Multifunctional flashlightCommercially available flashlights come in various shapes and varieties, but they only serve as lighting and have no other functions.In cities, due to the bright lights, fewer and fewer people use flashlights. The areas in the city where more flashlights are used are rural areas and remote mountainous areas. As far as the lighting function is concerned, the function of the flashlight is too simple. If you are walking on a remote mountain road at night and encounter a ferocious beast, the flashlight has no protective effect. Although the public security situation in today's society is improving, robberies and gangster criminal activities still occur from time to time, making people worry about the possibility of being robbed when they go out.How to relieve people's fear? In addition to severely cracking down on various criminal elements, another way is to strengthen one's own self-defense. According to the social nature and laws of our country, private individuals are not allowed to carry guns. In order to solve the problem of self-defense, "high-voltage electric guns" and "high-voltage electric batons" were introduced in the society some time ago, but were later banned by the public security department. The reason is that good people bought them for self-defense, but gangsters bought them to facilitate crime. Therefore, it is appropriate to ban the production and sale of high-voltage electric guns and high-voltage electric batons, but people cannot stop eating because of choking. For this reason, we designed the "Multifunctional Flashlight".1. Functional featuresDepending on the environment and scope of use of the flashlight, it has the functions of lighting, intimidation, alarm and high-voltage self-defense.This multifunctional flashlight has a high-voltage self-defense function that works synchronously with the alarm sound. If a gangster wants to use the high-voltage function of the multifunctional flashlight to commit a crime, it will emit a loud alarm sound, which will undoubtedly set the gangster on fire. This limits the gangster's attempt to purchase a multifunctional flashlight to commit crimes.For good guys, with a multifunctional flashlight, no matter day or night, walking in rugged mountains or other places, if you encounter ferocious beasts or gangsters, you can sound the alarm in advance to scare them away. If the beasts or gangsters ignore the alarm sound and attack or rob the good guys, the good guys can use high voltage to attack the beasts or gangsters to achieve personal self-defense. At the same time, the loud alarm sound will also call the surrounding rescue personnel, which is perfect for multiple purposes.In order to prevent bad guys from buying back the multi-functional flashlight, the alarm part is dismantled, leaving only the high-voltage part for committing crimes. The design is such that the high-voltage part of the alarm will become ineffective when the alarm part is removed.It can be seen from the above that multi-functional flashlights will be welcomed by the masses in urban and rural areas.2. Circuit working principleThe circuit of the multifunctional flashlight is shown in Figure 5-1. It consists of three parts: a lighting circuit, an alarm sound circuit and a high-voltage generating circuit. alt="5-1.jpg (26637 bytes)">Figure 5-1In the figure, the power supply, K1 and light bulb ZD form the lighting circuit.BG1, BG2 and transformer B1 form an alarm sounding circuit. This circuit is an audio oscillation circuit, and its audio signal is approximately 1000Hz. The BG1 tube is an oscillation tube and is responsible for the oscillation task; the BG2 tube is a power amplifier tube and is responsible for the amplification task.BG1 forms a leading RC phase-shift oscillator. The three RC networks complete a 180° phase shift. The voltage output by the collector is positively fed back to the base, causing BG1 to oscillate. The audio oscillation voltage is sent to the base of the BG2 tube through the capacitor C4. After being amplified by BG2, a strong audio signal voltage is generated on the collector, and through the mutual inductance coupling of the transformer B1, it drives the speaker to sound.BG3, transformers B2, BG4, unidirectional thyristor SCR and transformer B3 form a high-voltage generating circuit of nearly 10,000 volts. Among them, BG3 and B2 form a mutual inductance coupled feedback oscillator. After the power is turned on, an impulse voltage is obtained in coil L1. This voltage is induced into coil L2. Through capacitor C6, the induced voltage in coil L2 is fed back to the base of BG3, where it is amplified by BG3 and a higher oscillation voltage is obtained in coil L1. Then it is fed back by L2 and amplified by BG3, which continuously replenishes the energy loss in the coil L1, and obtains a stable voltage in L1, causing BG3 to self-oscillate. As a result, through the boosting of the step-up transformer B2, an alternating voltage of more than a hundred volts is generated in the secondary L3 of B2, providing a stable alternating power supply to the high-voltage pulse generator.BG4, unidirectional silicon controlled thyristor SCR, pulse transformer B3 and bridge rectifier form a high voltage generating circuit. The alternating power supply of about 110V provided by the feedback oscillator is rectified by the bridge rectifier composed of D1 ~ D4, and then filtered by the resistor-capacitor network to obtain a DC voltage of about 130V to charge the capacitor C10. The relaxation oscillation switching circuit composed of a single-junction transistor BG4 and a silicon-controlled thyristor SCR causes the capacitor C10 to continuously charge and discharge through the primary winding L4 of the pulse transformer B3, and induces an alternating high voltage of nearly 10,000 volts on the secondary winding L5 of the pulse transformer for self-defense.3. Component selectionBG3 is an NPN-type high-power transistor, and NPN-type high-power transistors such as DD01 can be used.BG1 and BG2 are NPN type high-frequency low-power transistors, which can be selected from 3DG6 or 9014.BG4 is a single-junction transistor, such as BT33, etc.SCR is a one-way silicon controlled thyristor, which can be selected from 3CTS or plastic-encapsulated 3A/450V specifications.B1 is the output transformer of the semiconductor radio.B2 is an inverter step-up transformer, which can be made with E-type ferrite core. The cross-sectional area of ​​the iron core is 12×12mm. L1 is wound with 0.15mm enameled wire for 60 to 70 turns; L2 is wound with 0.25mm enameled wire for 25 to 30 turns; L3 is wound with 0.27mm enameled wire for 500 to 600 turns.B3 is a pulse transformer, which can be used directly with the integrated line output transformer (small size) of a 30.5-35.6cm (12-14-inch) black and white TV. When used, the largest group produced by the low-voltage winding should be selected.D1~D4 are rectifier diodes, which can be 2CP type or 1N4004 type.The withstand voltage of C7, C8, and C10 electrolytic capacitors must be greater than 250V; the withstand voltage of C9 electrolytic capacitor must be greater than 50V.R9 and R10 are fixed resistors with a power of 2W, and the other fixed resistors have a power of 1/8~1/4W.R1 180kΩ R2, R3, R4 2.2kΩR5 100kΩ R6, R8 50ΩR7 1kΩ R9 20kΩR10 680Ω R11 150kΩR12 20kΩ R13 300ΩR14 220Ω C1, C2, C3 0.03μFC4 10μF C5 10μFC6 0.33μF C7 20μFC8 47μF C9 5μFC10 33μFThe printed circuit of the multifunctional flashlight is shown in Figure 5-2. …

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