>
>I think my message bounced.
>
>Marv says that recovery time isn't important, based on the slow
>slew rate of powerline frequencies.
>
>What then makes sure the diodes all share equal voltages while
>turing off?
? Avalanche threshold. They don't need to share the reverse potential
equally. For example, if you had a 800piv diode in series with a 1200piv
diode, and a 1900v reverse pulse came along, would you want the diodes to
share it equally? // . Without "equalization", the sharing will be
according to ability. Add external "Equalization" and the 800v unit gets
gaffed. (see p. 11-9 in ARRL Handbook)
>If it is junction capacitance, you are in trouble.
? not as long as the capacitance of the P/N junction is in parallel with
a limiter -- i.e., the avalanche characteristic of the P/N junction. .
>
>The capacitance is not only not matched, it changes with reverse
>voltage. The lowest capacitance diode will turn off quickest, and
>that will lower capacitance even more in that diode compared to
>higher capacitance (slower) diodes.
>
>Reverse leakage current, unless you take the diode to the
>threshold, is extremely low. Are people claiming one diode goes to
>threshold and then the others start being forced to threshold as
>that single diode avalanches? Is that the mechanism that causes
>voltages to be "shared"?
>
? I think he's got it!.
>
- cheers, Tom
Rich...
R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
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