Mea culpa Obi-Wan. I did not explain myself properly. I used a pre C-R filter before the shunts filtercaps. That is 4700-5,6. The 25 V caps I got worried me and my trafo is some volt high. After that is standard 4700+4700 and setter is R10 per rail. On the 4 card pic I use an R1 per plus and minus for the lot.
You had the 10 ohm setter in mind for adjusting sire?
/C3PO
You had the 10 ohm setter in mind for adjusting sire?
/C3PO
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25% smaller setter for positive can give more balanced CCS with the benefit of hindsight if for newer current level test.
I'm not absolutely sure that I understood you correctly there Master but parallelling the negative 10R setting resistor with a 56R gives me approx 8,2R and results in a drop over the same at 1,637 volt, equaling 190 mA. Keeping the positive at 10R drops 1,915, equaling 191 mA.
Please note that this is measures over the setting resistor, yesterdays data was from 5,6R in pre filter.
Vout buffer says -10,7 +10,4 and offset 0,7 mV left and 0,6 mV right.
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Yes you got it. Trimming down the Rset unequally to compensate for the NMOS PMOS Vgs difference part of the current setting scheme in this schematic. Not something particularly useful in practice since at those regions the transconductance isn't differentiating enough with few mA, but aesthetically nice to have equal measurements in the CCSs. All MOSFETS in each board give out same heat at least now.
P.S. Yes, negative side in this case. Correct. Whatever side is weaker for any reason be it different LEDS or MOSFETS for that matter.
P.S. Yes, negative side in this case. Correct. Whatever side is weaker for any reason be it different LEDS or MOSFETS for that matter.
Phew. Drilling and threading 32 M3s pulls me to the dark side. It took almost 3 sixpacks and in the end I was almost in to the ethyl alcohol. But now sits here 4 stuffed boards.
I did some measures feeding them 1 by 1 by the trafo and two 5R6 ( closer to 5R5 actually) on the rectified plus and minus.
Im gonna try make a chart. First column is card, 1, second card 2 etc:
Voltage drop 5R5:.....0,988/1,260.......0,910/1,183......0,979/1,194.....0,975/1,188
Makes current mA:....180/229.............165/215...........178/217..........177/216
Vout buffer (-/+):.....10,01/9,98........10,11/10,09........10,08/10,04...10,07/10,05
First is negative rail, second is positive on all above.
DC offset L/R mA:......0,3/1,1...............0,7/1,6............0,04/2,8.........1,5/2,2
So, positive takes more current then negative but outputs slightly less Vout.
What does the Jedi Council say. Am I still with the rebels or should I go talk to the man in the mask (I.e. do you think I should plug it in)?
Staffan
So - where did you get those heat sinks?
So - where did you get those heat sinks?
Its Fisher and I got them from here https://www.elfa.se/elfa3~se_sv/elfa/init.do?item=75-592-30&toc=0&q=75-592-30
Staffan
Can I get away with a transformer with 18V secondaries? PSU caps will be 60V rated... still planning on 10R resistors although I should have enough heat sink to go down to 5R or perhaps 3R. Any other special considerations or adjustments required?
If your sinks still keep the CCS Mosfets at tolerable heat on their plastic cases then you can use all that extra VAC. Non efficient, but if you must...
Can I get away with a transformer with 18V secondaries? PSU caps will be 60V rated... still planning on 10R resistors although I should have enough heat sink to go down to 5R or perhaps 3R. Any other special considerations or adjustments required?
I would load it down with around 30 down to 12-15 ohm resistor after rectifiers and cap, do some math and see what your up against to burn. One volt up and down counts under those circumstances.
Staffan
Henryve,
Hard to tell from his website, looks good thought and he sells some hi quality caps.
Ask him for a guarantee, in writing. Then buy some and see. I have no personal experience with that website. Even if others do, it would be almost meaningless unless they bought the 2SK170bl. Sorry no help to you.
Ron
Hard to tell from his website, looks good thought and he sells some hi quality caps.
Ask him for a guarantee, in writing. Then buy some and see. I have no personal experience with that website. Even if others do, it would be almost meaningless unless they bought the 2SK170bl. Sorry no help to you.
Ron
Quick question.
Can I trust the 2SK170BL from Hi Fi Tuning to be genuine?
Henry
I've never dealt with Hi Fi Tuning but Spencer on the forum provides well matched jfets with quick service.
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