Without knowing anything about this R-core (for example p-s capacitance), it's hard to say anything.
In #16 the old EI may be adequate, if the secondary DCR enough low, and you use appropriate schematic (C-r-CMC-C or coke input with low DCR choke).
You should decide what you want.
In #16 the old EI may be adequate, if the secondary DCR enough low, and you use appropriate schematic (C-r-CMC-C or coke input with low DCR choke).
You should decide what you want.
I guess with these power tx can't do input choke, only can do C-L-C or C-CMC-C, wich one better?
I now measured some 24V transformers (2.5...5A) with my -good- LCR meter (DVM gives only informative values).
The secondary DCR varies 0.28 ...0.1 Ohm.
I'm afraid, that this 24-0-24 EI core transformer with 2x0.9R secondary won't be good.
The R-core voltage is may enough, the p-s capacitance acceptable, must to try it.
I suggest to try PT-diodes-C-L-C with appropriate resistor as load: series connected 8R+8R 30-50W (later used as filament bias resistor).
For example 22V raw supply output as goal and 16R load =1.375A
If the raw supply PSU fulfil it (or greater), suitable for this LT power supply.
If the output voltage collapsing, must to search better transformer.
The secondary DCR varies 0.28 ...0.1 Ohm.
I'm afraid, that this 24-0-24 EI core transformer with 2x0.9R secondary won't be good.
The R-core voltage is may enough, the p-s capacitance acceptable, must to try it.
I suggest to try PT-diodes-C-L-C with appropriate resistor as load: series connected 8R+8R 30-50W (later used as filament bias resistor).
For example 22V raw supply output as goal and 16R load =1.375A
If the raw supply PSU fulfil it (or greater), suitable for this LT power supply.
If the output voltage collapsing, must to search better transformer.
I guess the TME power tx isn't enough with 1,35A to power the 1,25A required for filaments!!!
Are you sure the RS power tx can be used to power the two filaments, have separate bobbin parts between primary & secondary also 50VA each secondary?
I'm afraid the two R-Core are too big for mine PSU box...
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LL1694 as CMC capable 1.5A (2.4A saturation) after first capacitor as C-CMC-C filter.
If you use your old R-core 2x21V 120VA, this raw supply may enough good.
Try to set raw supply output voltage such level, which enough for R.C. regulator.
If you use V9, ask Rod for necessary headroom.
This sample schematic use 5V headroom for V7, V9 requiring lesser.
With varying the two small resistor value the necessary voltage may setting.
The first filtrating capacitor (C2) must be high ripple capable.
If you use your old R-core 2x21V 120VA, this raw supply may enough good.
Try to set raw supply output voltage such level, which enough for R.C. regulator.
If you use V9, ask Rod for necessary headroom.
This sample schematic use 5V headroom for V7, V9 requiring lesser.
With varying the two small resistor value the necessary voltage may setting.
The first filtrating capacitor (C2) must be high ripple capable.
Received by R. C. email about rules for filament bias:
Here are the Rules:
MAX V(out) = BIAS + 4.5V
MIN V(out) = BIAS + 2.5V
FilBias R = BIAS / (1,25 + Ia)
Here are the Rules:
MAX V(out) = BIAS + 4.5V
MIN V(out) = BIAS + 2.5V
FilBias R = BIAS / (1,25 + Ia)