[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-detail-561111-en":59,"doc-seo-561111-105":80},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":5,"data":60},{"doc_id":61,"user_id":62,"nickname":63,"user_avatar":64,"doc_module":4,"category_id":29,"category_name":30,"doc_title":65,"doc_description":66,"doc_content":67,"file_id":68,"file_url":69,"file_type":70,"file_size":71,"view_count":72,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":14,"language":73,"language_code":74,"site_id":75,"html_lang":74,"table_of_contents":76,"faqs":77,"seo_title":78,"seo_description":66,"update_tm":79,"read_time":24},561111,2336477552062,"Stanford","https://ap-avatar.wpscdn.com/davatar_994ba38a5ba835b3df7d355c54d3ed8d","CCFL teszter - The 8 Watt driver - Lamp Driver Circuit","CCFL teszter describes the design of an 8-watt CCFL lamp driver circuit developed in early 1999 during Chile’s drought-related power cuts. It explains how the driver differs from earlier versions by combining capacitive ballasting, a two-transistor saturation-limited oscillator, and a choke in the DC supply to improve waveform quality and reduce radiated noise. It also covers transistor selection, ferrite core loss behavior, and an inventive bottlenecked magnetic core approach to keep overall losses low.","CCFL teszter , [http://www.qsl.net/xq2fod/Electron/Fluolamp/fluolamp.html](http://www.qsl.net/xq2fod/Electron/Fluolamp/fluolamp.html)  \nThe 8 Watt driver  \nI developed this circuit in early 1999, when Chile was affected by a severe drought, most hydroelectric power plants had no water, and we were subjected to planned power cuts for two hours each day. I needed more battery powered lights in the home...  \nThe schematic for the 8 Watt driver will show you that this design is quite different from both previous ones. It uses capacitive ballasting like the 2 Watt driver, and a two-transistor saturation-limited oscillator like the 20 Watt design. But note an important difference: This circuit has a choke added in the DC supply, that produces more effects than you may think: Thanks to this choke, mutual conduction between the two transistors is no longer a problem, allowing for a very simple drive scheme and almost lossless operation. The input current becomes almost clean DC, minimizing further filtering requirements. And the waveform becomes a quite clean sine wave, which gives a tremendous advantage in terms of radiated noise! This lamp can be used in a radio station without causing any interference.  \nThe transistors used in this design are high-gain types. I just happened to have them on hand, salvaged from an old video recorder. You can use lower gain transistors, but then you must lower the value of the bias resistor (2k7 in my design) . No heat sinks are required.  \nThe ferrite core (detailed on the printable version of the schematic, obtained by clicking on this one) is one that was not designed for saturation-limited operation at this frequency. This kind of ferrite has considerable loss when operated at saturation flux densities at 25kHz, and so it gets very warm. It still worked well, but I was not satisfied with the performance. Not having a proper square-loop ferrite core in my material box, I came up with a solution that may well be an invention! At least I have not seen anyone using this before: The bottlenecked magnetic core!  \nI used a Dremel tool fitted with one of the green grinding stones (designed for very hard materials) to grind off some of the ferrite from the center leg of one E-half, as shown in this photo. The effect of this is interesting and very useful: At low flux levels the core has almost the same effective permeability it would have without this treatment. But the small section remaining after the grinding has to carry the same flux as the thicker rest of the core, and so works at a much higher flux density.  \nWhen the flux increases, this small section will saturate, while the rest ofthe core is still far from doing so. When the small section saturates, the core changes its behavior to that of an air-gapped core, drastically reducing its effective permeability! The result is that a saturation-limited oscillator built around this core will be controlled by saturation of just this little segment, while the rest ofthe core will work at a low flux density level. Only the small segment will run at the high loss level associated with saturation, while therest of the core will work at a very low volumetric loss! Since the amount of saturated ferrite is so small, the losses of it are negligible, and the overall core losses are very low despite working in saturation-limited mode!  \nHere is the completed circuit. Almost all parts were recycled from old equipment, which explains the white cement residueson the capacitor and the choke. Note that the primary winding isnot made from one solid wire, but from several twisted strands of thin wire. This makes it possible to wind it around this small bobbin, and also results in lower AC resistance.  \nI mounted this circuit into an aluminum canoe reflector made to size for the 8 Watt tube. This is very elegant, since the canoe is used as a return connection and ionization antenna, eliminating any visible wires  \n.  \nThis circuit is technically the best ofthe three, b","cbCaiprEOypJfz2B","https://ap.wps.com/l/cbCaiprEOypJfz2B","pdf",75585,3,"English","en",105,"# The 8 Watt driver\n## Circuit operation and advantages\n## Transistor selection and biasing\n## Ferrite core behavior and the bottlenecked core idea\n## Completed circuit and construction notes","[{\"question\":\"What key design changes make this 8-watt driver different from earlier versions?\",\"answer\":\"It uses capacitive ballasting and a two-transistor saturation-limited oscillator, plus a choke added to the DC supply to enable simple driving with almost lossless operation and cleaner DC input current.\"},{\"question\":\"Why does the choke help reduce interference and filtering needs?\",\"answer\":\"The choke produces effects that improve mutual conduction behavior between the transistors, yielding almost clean DC and a quite clean sine waveform, which greatly reduces radiated noise and interference.\"},{\"question\":\"What problem does the bottlenecked magnetic core solve and how is it implemented?\",\"answer\":\"A ferrite core not intended for saturation-limited operation at 25 kHz can get very warm due to high loss at saturation. The bottlenecked core is ground to reduce the center-leg cross-section, so only a small segment saturates, drastically lowering overall volumetric loss while keeping the oscillator controlled.\"}]","CCFL teszter - The 8 Watt driver - Lamp Driver Circuit | PDF",1791805033,{"code":4,"msg":81,"data":82},"ok",{"site_id":75,"language":74,"slug":83,"title":65,"keywords":84,"description":66,"schema_data":85,"social_meta":138,"head_meta":140,"extra_data":142,"updated_unix":143},"ccfl-teszter-the-8-watt-driver-lamp-driver-circuit","",{"@graph":86,"@context":137},[87,100,120],{"@type":88,"itemListElement":89},"BreadcrumbList",[90,94,96,98],{"item":91,"name":92,"@type":93,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":95,"name":9,"@type":93,"position":14},"https://docshare.wps.com/document/",{"item":97,"name":30,"@type":93,"position":72},"https://docshare.wps.com/document/technology/",{"item":99,"name":65,"@type":93,"position":19},"https://docshare.wps.com/document/ccfl-teszter-the-8-watt-driver-lamp-driver-circuit/561111/",{"url":99,"name":65,"@type":101,"image":102,"author":107,"headline":65,"publisher":109,"fileFormat":112,"inLanguage":74,"description":66,"dateModified":113,"datePublished":114,"encodingFormat":112,"isAccessibleForFree":115,"interactionStatistic":116},"DigitalDocument",{"url":103,"@type":104,"width":105,"height":106},"https://docshare.wps.com/thumbnails/ccfl-teszter-the-8-watt-driver-lamp-driver-circuit/561111.png","ImageObject",300,407,{"name":63,"@type":108},"Person",{"url":91,"name":110,"@type":111},"DocShare","Organization","application/pdf","2026-10-22","2026-10-12",true,{"@type":117,"interactionType":118,"userInteractionCount":72},"InteractionCounter",{"@type":119},"ViewAction",{"@type":121,"mainEntity":122},"FAQPage",[123,129,133],{"name":124,"@type":125,"acceptedAnswer":126},"What key design changes make this 8-watt driver different from earlier versions?","Question",{"text":127,"@type":128},"It uses capacitive ballasting and a two-transistor saturation-limited oscillator, plus a choke added to the DC supply to enable simple driving with almost lossless operation and cleaner DC input current.","Answer",{"name":130,"@type":125,"acceptedAnswer":131},"Why does the choke help reduce interference and filtering needs?",{"text":132,"@type":128},"The choke produces effects that improve mutual conduction behavior between the transistors, yielding almost clean DC and a quite clean sine waveform, which greatly reduces radiated noise and interference.",{"name":134,"@type":125,"acceptedAnswer":135},"What problem does the bottlenecked magnetic core solve and how is it implemented?",{"text":136,"@type":128},"A ferrite core not intended for saturation-limited operation at 25 kHz can get very warm due to high loss at saturation. The bottlenecked core is ground to reduce the center-leg cross-section, so only a small segment saturates, drastically lowering overall volumetric loss while keeping the oscillator controlled.","https://schema.org",{"og:url":99,"og:type":139,"og:title":65,"og:site_name":110,"og:description":66},"article",{"robots":141,"canonical":99},"index,follow",{"doc_id":61,"site_id":75},1792450557]