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THE AM BULLETIN BOARD => Technical Forum => Topic started by: xe1yzy on March 11, 2005, 07:44:44 PM



Title: H.V.Filament transformer question
Post by: xe1yzy on March 11, 2005, 07:44:44 PM
My Gurus...

The Filament transformer for the 866A in my BC610  have no CT in the secondary, only 5V output for filaments,  where suppose Im going take the HV output??  :?

Thanks for your help!


Title: H.V.Filament transformer question
Post by: John K5CEY on March 11, 2005, 08:33:58 PM
Well,

   Not much option here. I would say from either side of the 5 volt winding. I don't think this would be a problem.

For more modest powered applications, I have used two resistors across the 5 volt winding and taken the D.C. from the mid tap of the two resistors.
   Of course, then the effective resistance of the two resistors will be in series with the H.V.

I was just thinking, how about a pair of heavy diodes back to back across the filaments and pull the D.C. from the center tap. If I'm thinking correctly, they could be low voltage silicon jobs. Hmmm. Better draw that out on paper and chase current flow.

  John


Title: H.V.Filament transformer question
Post by: xe1yzy on March 11, 2005, 10:09:22 PM
Quote from: John  K5CEY

I was just thinking, how about a pair of heavy diodes back to back across the filaments and pull the D.C. from the center tap. If I'm thinking correctly, they could be low voltage silicon jobs. Hmmm. Better draw that out on paper and chase current flow.

  John


Hi John, good idea thanks, this rig comes with this transformer installed, but after so many years who knows if this transformer works or was the cause to discard the BC610.

Maybe Im go solid state all the PS at once, after all, I have to be sure when running 2500V DC isn't?, its more easy than try to found an original filament transformer anyways

thanks again an have a nice weekend John!
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