Tube DIY Asylum

Posted by Tre' (P) on September 28, 2024 at 14:32:09

In Reply to: RE: GZ34 rectifier..Can I get away with a 100uf first capacitor if.... posted by Iczerman on September 27, 2024 at 08:27:04

"Measured series resistance per winding is 100 ohms."
Do you mean 200 ohms across the whole secondary winding? That would be 100 ohms of series resistance per plate. It would really be a little more because the DCR of the primary winding is also factored in.

"the measured resistance of the choke is 100 ohms.
I think that is a factor."

Not unless it's being used as an input choke.

60uf input cap under each of the listed conditions and that includes the changing series resistance requirement. For 40uf (as many of the datasheets lists) the conditions would be different (higher load currents would be allowed and there would be a lower series resistance requirement for each of the conditions). Because the 40uf cap is smaller than a 60uf cap the diodes are each "On" for a bigger portion of the time so the peak current is closer to the load current (lower)
With a critical inductance input choke the series resistance requirement is gone (O ohms). This is because the critical inductance input choke causes each of the two diodes, taking turns, to be on for it's full half cycle. So current is being delivered to the filter all the time instead of only short bursts and this means the peak current is just about the same as the load current because the diodes are working longer, not harder.

Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"

Edits: 09/28/24   09/28/24   09/28/24   09/28/24   09/28/24