Re: "Flyback farm"- need help

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Stephen Conner by way of Terry Fritz <teslalist-at-qwest-dot-net>" <steve-at-scopeboy-dot-com>

At 13:13 09/04/03 -0600, you wrote:
>Original poster: "Jolyon Vater Cox by way of Terry Fritz 
><teslalist-at-qwest-dot-net>" <jolyon-at-vatercox.freeserve.co.uk>
>
>Dear List,
>I would like to build a "flyback farm" to supply my TCs with extra current.
>I have six flyback transformers (aka LOPTS)
>salvaged from colour televisions
>all with integral diodes and all of them of different.
>I have tested all of the flybacks with a 555 astable driven BU506 
>transistor (circuit diagram shown at http://hot-streamer-dot-com/temp/Flyback 
>Transformer HVGenerator.bmp) to determine the most appropriate primary 
>windings. All the transformers appear to be functional.
>
>My intention is to parallel the HV DC outputs
>but I am not sure about how to connect the primaries -will each 
>transformer need a BU506 to drive it
>or can they share a common transistor?
>
>In my scheme the base of the BU506 is driven via 10 Watt 10 Ohm wirewound 
>and a BD244C PNP driver transistor, switched by the 555 via a 1k base resistor.
>If six BU506s are needed I presume that six  wirewounds and six BD244Cs 
>will be needed also -but is this not an inefficient use of components?

That is probably the best way of doing it. The flybacks will all have 
differet turns ratios, so if you just parallel the primaries, they won't 
share the load equally. With an individual transistor for each they are 
forced to share. So it's an inefficient use of transistors and wirewound 
resistors, but an efficient use of flybacks.

Steve C.