Hello everyone,

I was wondering if anyone had any documentation/information on how to properly design and wind FL/HID ballasts? This is a subject I've become increasingly interested in as the supply of these ballasts gets smaller and smaller each day. I've started doing a little research on my own but I can't seem to find anything beyond what the circuit diagram inside a ballast is. Another collector who is also interested in the same idea is sending me a few Rapid Start FL ballasts for study but any info helps.  

 I have rewind a few ballast for this reasons.   I can tell u how this is done.  And turn ratio and numer of turns
 To make a ballast.

 so far  I can make single lamp F40 preheat ballast out of old
 2 lamp rapid start ballast.   By rewinding them or take  Existing
Stock working ones with a shunt capacitor.

PN me for more Details

Hello everyone,

I was wondering if anyone had any documentation/information on how to properly design and wind FL/HID ballasts? This is a subject I've become increasingly interested in as the supply of these ballasts gets smaller and smaller each day. I've started doing a little research on my own but I can't seem to find anything beyond what the circuit diagram inside a ballast is. Another collector who is also interested in the same idea is sending me a few Rapid Start FL ballasts for study but any info helps.  

Well, to design a ballast from scratch is a bit complicated. One thing you will confront at the start is that there is no straight receipt of 'how to cook a choke for a required design current, voltage, impedance and frequency. It may be optimized for the size (generally more copper, less iron), cost (more iron, less copper) or efficiency (more iron, more copper). Some things shall be selected empirically. Okay, for an arbitrary iron cross section you have to respect a hard limit of core saturation induction Bmax, so this will define a minimum of turns/volt. Next you select the wire gauge for some reasonable ohmic losses. And in the end you calculate/experimentally tune the air gap to get a proper design impedance. Some old Soviet textbooks pretend to have a complete set of formulas to do the calculations.

I won't touch DIYng  leak transformers, as this is even more tricky!

Fortunately, for DIY you are not constrained by the cost or size, so it may be possible to take some random transoformer/autotransformer of a suitable voltage (saturation) and winding gauge (heat) and, assuming laminates are not welded shut, rearrange the EI core inserting some carton as the air gap to create a choke with proper inductance.

First it very easy to Reuse the ballast core here in the USA
And it held together with two clips.   Number two
 the two lamp rapid start ballast is base off the single lamp preheat choke in designed.  They basically add 3 more coils
 To auto transformer preheat ballast for single lamp. With bit thicker wire on primary side of the ballast.  The way rapid start
 Works.  U have  just enough OCV  to cover the arc voltage of lamp with 10 percent Head room on the OCV.  How it works the
 Heating cathode winding first heat up cathodes with 210-220 volt ocv.  And heating the mercury help ionize the argon gas inside the tube.  Do to low OCV this why tubes are not driven
 To vacumme loss.

   Since 2 lamp  Rapid start ballast is base off the F40T12 single lamp preheat ballast.   It very easy to rewind these ballast if u  know the turn ratio and the thickness of the wire.

 I have been very secessful  winding up new ballast from old ballast cores as like I said it held together with clips on both
 Ends  u get two L peices and I core is the winding core.

   Once get the knowlage base down.  We should be able to make custom ballast.  To keep our lights going.   

  Problem is were going to run out of lamps at some point