Tom Rauch wrote:
>> 2. The HV supply will be an external, stand-alone unit. I am having
>> problems locating suitably rated HV connectors. The HV connector would
>> have to be a two pole type, making B- before making B+, and rated at >2.8
>> kVDC (to prevent the operator from being electrocuted)
>
>You might consider armored cable with a grounded metal shell,
>and using the second pin in the connectors as an interlock to
>prevent HV from being activated unless the HV lead is connected
>and the chassis are grounded together.
>
Multi-pole HV connectors are hard to find. Another alternative is to use
a coaxial HV-rated connector for the B+ lead and a multi-pole connector
to carry B-, the main chassis ground and also that "Enable" line that
Tom mentioned.
The Enable line makes sure that if that connector is not in place - and
with it the chassis ground and B- return - the HV supply cannot start.
(For example, it can be the DC feed to the mains contactor in the HV
supply.)
For the coaxial B+ connector, use SHV if you can (they're the safest),
MHV [*] if you must, but never an RF type!
For the Ground/B-/Enable connector I've standardized on 5-pin XLR: two
poles and shell for ground, two poles for B- and the last pole for
Enable.
[*] WARNING: do not use MHV connectors without a pre-existing ground
return or an Enable interlock. If you plug into a live HV supply, the B+
connects before the ground return does!
73 from Ian G3SEK Editor, 'The VHF/UHF DX Book'
'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.demon.co.uk/g3sek
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