My question in directly related to the use of old chokes and transformers. Here, I can get 5H 0,08A chokes for very cheap ~2,5USD, but they have been used in old tube TVs.
Because these chokes are very cheap, I'm building a C LCLCLCRC power supply for my tube DAC part with them. My goal is to eliminate electrolytics in the path. Because these chokes are so cheap, I can do 5-6x LC filters if I want to
.
So, the chokes are old, but what about the iron? These are from old russian tube TVs and could be at least 30-40 years old.
The same goes for power transformers. I have few that are center tapped and are perfect for tube rectifiers.
Because these chokes are very cheap, I'm building a C LCLCLCRC power supply for my tube DAC part with them. My goal is to eliminate electrolytics in the path. Because these chokes are so cheap, I can do 5-6x LC filters if I want to
. So, the chokes are old, but what about the iron? These are from old russian tube TVs and could be at least 30-40 years old.
The same goes for power transformers. I have few that are center tapped and are perfect for tube rectifiers.
Hi,
Modern iron might be somewhat smaller for the same peak flux,
and eddy losses might be lower depending on the lamination
practises used, but iron is basically iron in inductors AFAIK.
Same with power transformers, same issues.
At power supply frequencies both should be fine.
rgds, sreten.
FWIW a old valve amplifier trick :
This was usualy done using CRC type filters for dropping voltages,
and might work for CLC type filters to simplify them a lot :
For class A circuits the power supply load is constant.
If you have a supply that shifts the input phase by 180 degrees,
this can be right for 3 cascaded RC voltage droppers, you can then
"inject" the input ripple via a capacitor and high value resistor into
the 3rd stage output to cancel any residual ripple ... clever or what ?
Modern iron might be somewhat smaller for the same peak flux,
and eddy losses might be lower depending on the lamination
practises used, but iron is basically iron in inductors AFAIK.
Same with power transformers, same issues.
At power supply frequencies both should be fine.
rgds, sreten.
FWIW a old valve amplifier trick :
This was usualy done using CRC type filters for dropping voltages,
and might work for CLC type filters to simplify them a lot :
For class A circuits the power supply load is constant.
If you have a supply that shifts the input phase by 180 degrees,
this can be right for 3 cascaded RC voltage droppers, you can then
"inject" the input ripple via a capacitor and high value resistor into
the 3rd stage output to cancel any residual ripple ... clever or what ?
Last edited:
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