Return to the thumbnail page Display/hide file information See previous file See next file

Basic CFL circuit, used as a PL-S ballast

Basic CFL circuit, used as a PL-S ballast

Click to view full size image

This is the basic circuit, what is the base for most of selfballasted CFL's. Here is shown to feed a PL-S style lamp, the type with starter inside and intended "only for magnetic ballast". Inside the lamp is the starter, but the most important for this circuit, the capacitor.
R8 is a fuse (or a fusible resistor), what have to disconnect the mains when the ballast blow up.
Input diodes rectify the mains, C1 filter the DC voltage out (well, it's usual sizing ensure only about 150V as the minimum, so only allow to sustain the arc).
Then is two transistor half bridge, with the ring core transformer (the inductors with dots) providing the feedback.
For start, the R6 charge the C5 and when the voltage reach breakover voltage of the diac D6 (I did not have diac in my library, so I used diode symbol), it create pulse on the T2 base and the circuit start to oscillate.
Initially it oscillate close to the series resonant frequency of L1 and the capacitor inside the lamp. So the overall impedance of the Clamp+L1 is small, high current pass through, heating up the filaments. At the same time high voltage appear across the lamp and either ignite it directly, or after the filament warm up. When the lamp strike, it drop it's impedance, so the resonance disappear. The operation frequency drop so, the current regulated by L1 is about the desired lamp current.
Here, if the lamp fail to strike (e.g. it's filaments were not yet hot enough), the high voltage heat up the starter and after a while it closes, shorting out the lamp, so the resonant capacitor. With that the frequency drop and the current become about the normal lamp current, so nothing overloaded. During this time, only the filaments receive heating, so they continue to warm up. After some time the starter cool down and try to open, so restore the resonator, so the high voltage build up again and so on. If the lamp is good, it strike and the starter stop interfering. But if it is bad, the starter keep most of the time closed, so protect the ballast from overheating when in the resonance mode. And eventually some filament break, so interrupt the feedback, stopping the circuit.


Light Information

Light Information

Lamp Type:PL-S
Ballast Type:HF electronic

File information

File information

Download: Download this File
Album name:Medved / Reverse engineering
File Size:43 KB
Date added:Jan 24, 2013
Dimensions:1600 x 1200 pixels
Displayed:290 times
Favorites:Add to Favorites

Posts: 12
View Gallery

Collector SL lamps and other lamps and lanterns.

View Profile Personal Message (Offline)
Mar 04, 2013 at 03:41 PM Author: Lampka
I have one of adapter - Tungsram adapter for PL-C tubes, which have exactly similar ballast as it.

Collector SL lamps and other lamps and lanterns.

Full Member

Gender: Male
Posts: 109
View Gallery

220V AC 50Hz

View Profile WWW Personal Message (Offline)
Apr 11, 2019 at 08:02 PM Author: Binarix128
How is called this program? Looks interesting!

-I dont speak English very well. Compact Fluorescent (PL)
-Say NO to incandescent bulbs ban! Incandescent Lamp
-lamp saver Mercury Vapor Lamp

Sr. Member

Gender: Male
Posts: 296
View Gallery


View Profile Personal Message (Offline)
Apr 12, 2019 at 05:44 AM Author: rjluna2
They are orónicos for your language

Pretty, please no more Chinese failure.

© 2005-2019 | Powered by: Coppermine Photo Gallery