Steve Thompson wrote:
>
>
>>What does the voltage regulation look like, from 'zero' current (bleeder
>>resistors only) to say 100mA ZSAC and then to 300mA peak?
>
>With Glenn's new data, at 5mA load, 2300V, at 300mA, 2150V. Rs calculates at
>29 ohms.
>>
>>What diode model did you use... and can you e-mail it please?
>
>Here's the line I added to the 'rectifier.txt' file:
>EHT, SS, 0.2, 20, 9.35, 6000, 200, 99
>
>I'll leave anyone interested to collect their own version of the software
>and decide if my model is duff.
>
Not duff at all, Steve. I get the same values as you, so I was wrong
about including the resistance contribution of the diode strings.
It seems that the diodes should be regarded as only a source of forward
voltage drop, which is too small to matter in a HV supply.
A good fit to the design charts seems to be simply Rs = R_secondary +
N^2*R_primary (where N is the step-up turns ratio). For Glenn's
transformer, Rs comes out as 29-30 ohms, same as Steve found, and using
that value the chart agrees with the SPICE model.
So it looks like you're in business with that transformer after all,
Glenn. Sorry if my pessimistic analysis gave you a bad 24 hours!
Even so, that doesn't change the fact that FWD is *much* more sensitive
to Rs than FWB is.
73 from Ian G3SEK Editor, 'The VHF/UHF DX Book'
'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.com/g3sek
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