CFL Inverter transformer insulation problem
CFL Inverter transformer insulation problem
(OP)
I have an inverter project for emergency lighting with two 110W CFLs. The circuit uses bipolar transistors powered from 12VDC in a self-oscillating push-pull topology. Both lamps must be insulated from each other, which requires to have isolated secondary windings. Lamps are connected through 1nF/1600V polipropylene capacitors. Transformer data: Standard ferrite E-core 30/15/7 (mm). 7+7+2/330+330 turns. Freq. 30KHz. Enameled wire is 180ÂșC and 2500V class.
The circuit efficiency is reasonable good. However, insulation leakages happen frequently between turns from different layers in the same secondary winding. The winding is made manually and layers are not perfect (turns from different layers may become side by side). Secondary steady state voltage on each 110W CFL lamp is about 800Vpk-pk, and when 32W CFL lamps are used, secondary voltage is about 400V, however insulation problems still happen.
When the two secondary lamp circuits are left independent (isolated from each other) operation is OK. Unfortunately, this in not true for real operation, where any secondary end is connected to any end of the other, thus causing the referred problem.
Any ideas will be welcome.
betkro
The circuit efficiency is reasonable good. However, insulation leakages happen frequently between turns from different layers in the same secondary winding. The winding is made manually and layers are not perfect (turns from different layers may become side by side). Secondary steady state voltage on each 110W CFL lamp is about 800Vpk-pk, and when 32W CFL lamps are used, secondary voltage is about 400V, however insulation problems still happen.
When the two secondary lamp circuits are left independent (isolated from each other) operation is OK. Unfortunately, this in not true for real operation, where any secondary end is connected to any end of the other, thus causing the referred problem.
Any ideas will be welcome.
betkro





RE: CFL Inverter transformer insulation problem
http://www.mwswire.com/
produces and stocks magnet wire with up to a four layer insulation build up.
RE: CFL Inverter transformer insulation problem
RE: CFL Inverter transformer insulation problem
RE: CFL Inverter transformer insulation problem
RE: CFL Inverter transformer insulation problem
http://www.eis-inc.com/
RE: CFL Inverter transformer insulation problem
RE: CFL Inverter transformer insulation problem
Yes, "Lead Pipe Chinch" means "Guranteeded to Work." What would be the British Slang equilent?
RE: CFL Inverter transformer insulation problem
Well, there are lots of phrases in British slang that mean "guaranteed to work" or similar. A couple of the more printable ones are "stone bonker", "dead cert".