Hangzhou Sehon Technology Co., Ltd.
Why cheap LED ball steep light easy bad light bead
now LED ball steep light, whether in or on the roadside stall to buy online purchase, the price is very cheap, three to five yuan a, but this kind of cheap LED ball steep light is arguably & other; Save electricity don't save money & throughout; 。 Buy a ball bubble lamp in less than a few months, some will be out of order, and are mostly LED lights burn out. This article is to introduce in detail the cheap LED ball steep light why easy bad light bead?
? Bring cheap LED ball bubble lamp driver circuit principle diagram.
cheap LED ball steep light resistance capacity of the commonly used antihypertensive LED driver circuit. AC220V the capacitor C1 step-down current limiting and rectifier bridge rectifier, drive 28 series white LED lamp bead light.
? Bring to a burning LED lamp bead ball steep light.
? Bring about the LED ball steep light circuit board. The above MB6S is 0. 5 a / 600 v patch rectifier bridge.
? Bring about circuit boards welding 1 & mu; F capacitance and 2. 2μ F capacitance is the schematic diagram of C1 and C2.
this ball steep light is burn out twice LED lamp bead, for the first time in a patch of 2835 LED lamp bead after repair, took a month or so and lamp bead is broken ( Take last summer) 。 So doubt the two capacitance has a problem, remove the measured the capacitance, the normal capacitance C1, C2 capacitance measured only 0. 1μ F a little more. From the waste fluorescent lamp electronic ballast circuit board and remove a of electrolytic capacitor changed into the same specification, yet fail again.
why smaller capacity would be easy to damage the filter capacitor C2 lamp bead? We know that the capacitance in the moment of turning on the power supply, the voltage on both ends is zero, not mutation. Of the schematic diagram for C1, because of its large capacity, each time you turn on the light, the voltage is zero at the ends of the C1 increases gradually, this will produce an impact current, if the C2 is not damaged, it can absorb the impact current, so the LED lamp bead is not easy to damage. When C2 capacity become very small and cannot be fully absorbed when turn on the light of the impact current, which is fragile LED lamp bead at every turn on the light when it is easy to damage.
? Bring after repair, in order to test the LED lamp bead, working voltage and current, welding the two components on printed circuit boards in pin.
bring measured in 28 series of LED lights, the total positive pressure drop to 84. 7V。
? Bring the measured these series of LED lights, the working current of 44. 84mA。
as a result of the 2835 LED lamp bead working current is bigger, and some manufacturers in order to reduce costs, the LED lamp bead welding in general on the PCB, the cooling effect is inferior to the aluminum substrate, which is the cheap LED ball steep light easily damaged during the summer heat lamp bead another reason.