>Tuned to resonance with no load, when you need it the most. When
>current load is increased, the tuned choke's equiv impedance falls to
>that of inductive reactance alone as the L changes (drops). That is
>enough for regulation under higher current.
? Not only that, but a resonant-choke filter can handle rapid
fluctuations in load current (as with SSB) , something that neither a
swinging-choke filter or an ordinary choke filter can manage. And, as
an added FREE bomus, a FWB, resonant-choke filter allows about 20% more
DC current to be drawn than the transformer's AC-RMS rating - for the
same temperature rise . However, just the opposite effect applies to
capacitor-filter rectifier circuits.
>>re: tuned filter power supply
>>Is the target 'trap' frequency actually 120 Hz or
>>slightly above it?
>>--------- Forwarded message ----------
>>From: "John T. M. Lyles" <email@example.com>
>>The cathode (-) power supply may have a large steel canned capacitor
>>around 1 uF. It is rated for high AC voltage in doubler service, and
>>is usually polypropylene dielectric. If it is rated for few kV, it
>>makes a very nice capacitor for tuned filter power supplies, across
>>the appropiate choke to make a 120 Hz parallel 'trap'.
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