UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - 800 to 900VDC from 250-0-250, do I have this circuit correct

AdrianH · 27th Jul 2020, 8:49 pm

I am sorry for the hand drawn scribble I hope it can be deciphered.

I have a 250-0-250 transformer I wish to use on a project, but I also need between 800 and 1000 Volts max for a CRT.

So I have drawn what I think is correct, but I would appreciate knowing if it is correct, or if wrong where I have I gone wrong.

Is there a better way, I am only needing 1 possibly 2 mA to drive a DG7-5 CRT.

On the caps that I would need for the HT would 3 x 0.47uF caps do as I can get these rated at 1000 Volts or would I be better doubling these in three sets of two?

Lastly, the diodes I think would only need to be 800 Volts PIV as looking at what I have drawn I hope that no diode will see more that the 353 x 2 volts at peak reverse?

Thanks in anticipation for your help.

Adrian

27th Jul 2020, 8:49 pm	#1
AdrianH Octode Join Date: Mar 2020 Location: Blackburn with Darwen, Lancashire, UK. Posts: 1,573	800 to 900VDC from 250-0-250, do I have this circuit correct I am sorry for the hand drawn scribble I hope it can be deciphered. I have a 250-0-250 transformer I wish to use on a project, but I also need between 800 and 1000 Volts max for a CRT. So I have drawn what I think is correct, but I would appreciate knowing if it is correct, or if wrong where I have I gone wrong. Is there a better way, I am only needing 1 possibly 2 mA to drive a DG7-5 CRT. On the caps that I would need for the HT would 3 x 0.47uF caps do as I can get these rated at 1000 Volts or would I be better doubling these in three sets of two? Lastly, the diodes I think would only need to be 800 Volts PIV as looking at what I have drawn I hope that no diode will see more that the 353 x 2 volts at peak reverse? Thanks in anticipation for your help. Adrian Attached Thumbnails __________________ Asking questions and learning, or trying to! Youtube EF91Valve