2 wrote:
>
>
>>
>>
>>> >
>>> ** During an HV- to gnd arc,
>>> no -- but during a VHF/UHF
>>> parasite, an
>>> 8877 is capqable of >50A-pk
>>> cathode current (Ik).
>>> However, 50A would
>>> torpedo a 10A transistor (Q1).
>>
>>Doesn't your proposed opto controlled
>>bias switching transistor have the same
>>torpedo problem during a parasitic??
>>
>** Quite rightly, Paul. This is why the 100V npn switch transistor (Q1)
>is protected by the 51V, 1500W-pk voltage surge suppressor diode.
>
And I do the same with my transistor using large varistors (as shown on
the web page).
In all out installations, the maximum possible current is also limited
by the glitch resistor in the B+, so we have a firm value to design
against.
--
73 from Ian G3SEK
www.ifwtech.co.uk/g3sek
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