I`m OK. Just collect all parts (from tubes to screws).
Heatsinks was missed and reordered at Digi
+ some MOSFETS ordered too.
STM STP7NM50N, much better IRF820 - very low Rds 0.78 Ohm.
IRF820`s Rds is 2.6 Ohm. BTW IRF820 is a obsolete (as I know).
Case drawing done (basically modification for semi-custom case).
I`m totally rethinking about chassis. Will do "open tube" design 210 x 290 mm. only (A4 paper format)
I will finish with transformer testing today.
U(sec1) = 274-276 VAC
U(sec2) = 275-278 VAC
U(sec3) = 6.78 VAC
U(sec1) = T.B.D.
U(sec2) = T.B.D.
U(sec3) = 6.33 VAC @ 4.22A (Rload = 1R5)
-- Best Regards,
Transformer test result:
Tested with HP 3457A bench multimeter
Under full load`s (simultaneously):
U(sec1) = 267.3 VAC @ 108.4 mA (Rl = 2.4664 kOhm)
U(sec2) = 263.6 VAC @ 106.7 mA (Rl = 2.4688 kOhm)
U(sec3) = 6.23 VAC @ 4.22A (Rl = 1R5)
I think 3.7 V delta between HV channels is not a problem
3x 0.5 Ohm 25W resistors (serially connected)
12x 3.3 kOhm, 2W (NOS USSR OMLT-2 type ) resistors "cluster"
Each "cell" combined from 4x 3.3 kOhm resistors in parallel connection.
3x "cells" connected serially.
Edited by LV26 - 3/19/14 at 4:48am