(1) UV fluorescent tube is not bright There are usually […]
(1) UV fluorescent tube is not bright
There are usually two cases in which the UV fluorescent tube is not bright: First, the 220V mains does not enter the mosquito lamp circuit, and there is no voltage on the high voltage grid. In this regard, you can first check whether the 220V mains is normal. If it is normal, check whether the power plug and the socket are disconnected or have poor contact. If there is still no problem, you need to dismantle the mosquito lamp. Usually, the power wire is loosely soldered, and the fault can be eliminated after re-welding. A few may also be caused by an internal disconnection of the power cord, which can be reconnected or replaced with new ones. Second, the 220V mains has entered the mosquito killer circuit, and the voltage of the high voltage grid is normal, which indicates that the fault is only in the UV fluorescent tube circuit. Removable mosquito lamp housing, first look at whether the lead between the lamp and the printed circuit board is off-welded or open circuit, and if so, reconnect; if not, check whether the contact between the lamp and the lamp holder is good. If the contact is poor, re-tighten the lamp. If there is no problem with the contact, it is that the lamp is broken. It is common that the lamp is used for a long time and the lamp is leaking. Generally, the lamp of the same specification is replaced.
It is worth pointing out that the service life of the lamp is not only related to its own quality, but also has a great relationship with the method of use and fluctuations in the mains voltage. Therefore, the use of mosquito killer lamps should minimize the switching power supply. It is best to switch only once a day. At the same time, it is best not to use it in indoors where the mains voltage is too high or too low. This will prevent the lamp from aging prematurely and prolong its service life. .
(2) The UV fluorescent tube is bright, but the high voltage grid has no voltage.
The method of judging whether there is voltage on the high voltage power grid has been mentioned before. There are two main reasons for this failure: First, the lead of the voltage doubler rectifier circuit or the printed circuit board wire has an open circuit. Usually, it is measured by a visual or multimeter. The fault point can be quickly detected and carefully re-welded. Solve the problem. Second, the diode, resistor or capacitor in the voltage doubler rectifier circuit is damaged. During the inspection, R1, VD1, VD2, VD3, and C2, C3, and C4 in Figure 2 can be inspected one by one. Since there are not many components, the fault is usually found very quickly. If the diode is damaged, it can be replaced by 1N4007 or 1N4006. If the capacitor is damaged, it is recommended to replace it with a non-polar capacitor with the same specification capacity and withstand voltage of 400V or higher. Because some manufacturers of mosquito killers reduce the cost, the capacitors used have lower withstand voltage specifications, so the failure rate is higher, and the replacement of high-quality capacitors during maintenance can avoid or reduce such failures. In addition, when there is a short-circuit fault in the high-voltage power grid, the high voltage will disappear. Therefore, check whether the high-voltage power grid has a short-circuit fault during maintenance, and if so, it should be excluded.