Analysis of Common Faults of Electric Mosquito Beat
Date of release:2019-01-11 Author: Click:
Electric mosquito racket made in DC high voltage will produce a certain intensity spark. Therefore, it is strictly forbidden to use and repair in places full of flammable gases. Do not contact the high-voltage power grid with hands or conductive metal bars when electrifying, in order to prevent accidents. Electric mosquito swatter is not a toy and should not be used by children.
1. Power Switch
The power switch of the electric mosquito racket is usually a 6 x 6 mm touch miniature key switch, which operates under 120 to 200 mA conditions. Due to frequent operation to turn on and off the power supply, it is easy to damage. There are two forms of damage:
(1) Poor contact with oxidized contacts, no light on indicator, no work of electric mosquito racket.
(2) The reed is tired, the contact sticks to death, the indicator lights are always on, once equipped with batteries, the electric mosquito racket will work. The miniature switch is small in size and troublesome in maintenance, so it is usually renewed.
2. Boost Transformer
The damage forms of booster transformer are mostly secondary L3 turn-to-turn insulation breakdown, which shows that T can not hear the "squeak" audio sound at the instant of power-on, and there is no spark when touching metal mesh. The normal resistance value of L3 ends measured by multimeter Rxl block is about 80_. If the circuit is broken or lower than the normal resistance value, it will be regarded as damage. Another inspection method is to cut copper foil on the secondary transformer with a cutting knife and measure both ends of L3 with a multimeter AC gear. Normal AC voltage reading is about 230V, if no voltage is considered damaged.
Weld the T pins, remove the transformer, pull out the black core, remove the external insulation. Remove the next enameled wire and record the number of turns. Then rewind the high strength enameled wire with 0.08-0.12 mm QZ. The enameled wire can be removed from a bad small ceiling fan or a bad power transformer.
The L3 resistance value of secondary winding of transformer T is 80_normal. If there is no 230V voltage at both ends of L3, most of the faults are caused by VT damage of oscillator tube. Welded oscillator tube, using multimeter detection to judge good or bad. Replace with prototype number S8050 or NPN transistors such as D467, D468 and 9013.
4. Voltage doubling rectifier elements
The capacitance C1-C5 of voltage doubling rectifier element and VDl-VD5 of diode break down short circuit or open circuit of any element will cause no high voltage or insufficient high voltage. The main reason is the insufficient voltage withstanding of components or the poor electrical performance used. Multimeter test is required. C1 or VDl breakdown is common. After the capacitor is damaged, replace it with 333J/630V polyester capacitor: after the diode is damaged, replace it with lN4007 silicon rectifier tube.
5. Battery boxes and batteries
Battery box failures are mostly due to leakage of batteries, resulting in corrosion and oxidation of positive copper sheets or negative spring, poor contact, resulting in the electric mosquito racket does not work, completely scrape away the rust with a knife. If the electric mosquito racket is not used for a long time, it is advisable to discharge the battery, which is the best way to prevent electrode corrosion and oxidation.
Batteries consume electricity for a long time. If the voltage of each battery is less than 1V (the brightness of LED is darker), it will cause insufficient high voltage and bad mosquito control effect. Replace two new batteries.
6. High Voltage Metal Mesh
Long-term use or collision with objects will cause deformation and loosening of high-pressure wire mesh, which may cause instantaneous short circuit and spark. Users thought they had hit mosquitoes, but they didn't know that something had gone wrong. If contact short circuit can cause damage to rectifier elements and transformers, it is necessary to check and maintain frequently. It is found that deformed steel wires need to be shaped and loose wires need to be reset and bonded with yellow viscose.
1. Indicator VDl is not on: Under the condition of normal battery G power supply, the failure of multi-button switch SB caused by poor internal contact. SB is 6mm & TImes; 6mm vertical miniature light touch switch, frequent switch under 120mA working current condition, it is very easy to cause internal contact oxidation open circuit, new can be used to remove the fault.
2. VD1 is bright, but no high voltage is produced: at this time, the audio "squeak" produced by transformer T at the instant of power-on can not be heard. Sound, indicating that the oscillating circuit does not work. Most of the reasons for the failure are VT damage, and the replacement of 2N5609 or D467 new tube can eliminate the failure. If there is no such tube on hand, 8050 and 9013 NPN transistors can be used instead, and the effect is good. If the VT is not damaged and hot after power-on, it shows that the breakdown of transformer T inner coil (especially high-voltage coil L3) must be rewound with enameled wire of the same specification. Generally, this kind of fault is rare.
3. Insufficient high voltage: The main reason is that the capacitor in c1-c 3 is open circuit or the capacity becomes smaller, or one of the diodes vD2-vD4 is damaged, so it is necessary to detect and replace new ones. In addition, insufficient G voltage of battery (the brightness of vDl obviously decreases) will also cause insufficient high voltage, so long as new batteries are replaced, failure can be eliminated. Electric mosquito racket is the principle of inversion, which converts direct current into alternating current, and then generates more than 1000 volts of direct current voltage through voltage doubling. It uses high voltage to shock mosquitoes.