Bill Turner wrote:
On Sun, 11 Apr 2004 05:25:02 GMT, wrote:


I'd use
2 51K 2 watt resistors in series across each cap, to
give a very good safety margin on the resistors' power
dissipation and voltage exposure.


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Also, avoid carbon composition resistors. They are notorious for
gradually changing their resistance over time. Metal oxide film (MOF)
types are much more stable over the long run. Richard, AG6K, sells them
pretty reasonable. See http://www.somis.org/

The time proven method uses wire wound power resistors, with somewhat
lower values (higher wattage). For 450 volt caps resistors in the 50k
range are common, this will require 5 watt resistors (use 10w to be
safe). The higher bleed current serves two purposes, it discharges the
capacitors when the power is shut off more quickly, and reduces the
peak voltage reached protecting the capacitors. High voltage capacitor
strings using higher value resistors can hold a charge for several
minutes, a hazard for the careless!


Richard's resistors are 100K and are rated at three watts. With 416
volts applied per your example, they dissipate 1.7 watts, which should
be a sufficient safety factor. The truly paranoid may connect four of
them in a series-parallel arrangement across each capacitor.

--
Bill, W6WRT
QSLs via LoTW