Swinging Choke?

Gungnir

Member
2013-10-23 4:09 pm
CA
Would this be considered a swinging choke?
 

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Gungnir

Member
2013-10-23 4:09 pm
CA
You do not really have to use a swinging choke in a choke input filter. It just saves some cost and weight to have a swinging choke.
If the choke is potted and rated for 400ma, you are probably fine.

That's what I was thinking too, I have a pair of these chokes and I really want to use them (they take up a lot of storage space), they are impressive @ over 20lbs a piece!
 
You do not need a swinging choke for a constant load.

The reason for a swinging choke is to meet the low current requirement which requires a high critical inductance.

For example an amplifier with 400volts plate 50ma idle and 200ma peak.
400 volts/50ma gives you 8H required for critical inductance.
You only need 2H with the 200ma load. So you can allow the inductance to drop when the current is over 50ma and save a bit of weight. They just put a very small gap in the choke so it has high inductance at low current but that will drop inductance with current.
 
A choke input filter applies a much higher AC voltage across the choke itself, as compared to a choke in a more typically seen (nowadays) CLC configured filter where the choke may only have 5-10Vrms across it.

Not only does a choke for a choke input filter have a higher Vac across it, it experiences a higher peak working voltage (B+ level plus a contribution from the AC peak) for the same B+ output level benchmark.