Hongguang brand electronic ballast circuit diagram

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Hongguang brand electronic ballasts are known as “no pollution”. Dealers say that such ballasts will not interfere with other electrical appliances when they work. (Ordinary electronic ballasts generate a lot of harmonics when working, if the filter circuit does not Good, it will make these harmonics enter the power grid and affect other household appliances. As long as the lamp does not leak, the lamp that has broken the filament can also be used, and the energy saving effect is remarkable. Can not help the dealer's temptation, I bought two such ballasts. After the trial, I feel that the effect is ok. The regulator can adjust the input voltage to illuminate the lamp at 160~240V, and the brightness is similar to that of the ordinary magnetic ballast. (As for whether the filament lamp can be lit, I have not tested it). After disassembling it, it was found that its internal circuit is quite simple and is now introduced to the reader for imitation by interested parties.
The ballast circuit is shown in the drawing. Capacitors C1 and C2 are step-down capacitors, D1 to D4 are rectifier diodes, and C3 and C4 are ignition capacitors. R1 and R2 are current limiting resistors. After the 220V power supply voltage passes through the voltage doubler rectifier circuit composed of D1~D4, C3 and C4, the voltage at both ends of a and b can reach 600V or more. This voltage can completely illuminate the lamp H.

To be correct, this is a quadruple voltage rectification circuit. When the lamp is not lit or the lamp is not installed, the voltage at both ends of a and b can reach 4×√2×220≈1200V. The advantage of this type of circuit is that because the filament is not preheated at all, it is no problem to break the wire, even if the lamp has broken at both ends, it can be reused. The disadvantage is that, for various reasons, sometimes it is not possible to start lighting at one time, and it is necessary to turn on/off the power supply multiple times to light up. In addition, it is not necessarily "energy-saving" because the power dissipation of its current limiting resistors R1, R2 is not necessarily less than the active power of the ballast. If the reader wants to copy, C3 and C4 should take the pressure of 630V.