What caps are these????

[freakyone]

Im in the process of purchasing 8 s/h caps, 4 for each channel

Does anyone know just what im about to buy?......

eg manufacture date


these are the specs

pwm2a1v04
100 000 uF
35WV 44SV
+85oC
OG10A-T

CLC design, L being 1.8mh

Cheers!
Dan

 

[freakyone]

Hello again!

I forgot to add that this will be the PSU for my aleph-x (my first go at diy), when looking at caps this large do I need to look at adding a soft start????????????

Cheers

 

[sss]

for 100000uf a soft start is a good idea

 

[jacco vermeulen]

manufacture date

manufacture date:
pwm = production week of manufacture.
2d week,2001.
35WV = operating voltage
44SV= surge voltage (= maximum peak voltage)

 

[MikeB]

L being 1.8mh

Is that a typo ?

Mike

 

[Eva]

Those 1.8 mH inductors must have at least 0.17 ohms resistance, otherwise the resulting LC system will resonate like crazy at 10Hz, and when excited with the proper audio signal this will probably result in overvoltage to the capacitors and the amplifier.

Inductor saturation current must be also taken into account, since they will stop filtering after this current level is reached. CLC filters are probably not well suited for beginners.

 

[freakyone]

Thanks for reply guys!

I am thinking of purchasing some 14 AWG and winding four chokes using Barry's Inductor Simulation as guidence, which should give me a DCR of about .4ohms, If I was to cut four lenghts the same at 40m and wind these up I cannot imagine this being to difficult and the Inductance should be the same.


With this DCR and the alephx being constant current shouldnt this cause very low resonance?

Cheers

Dan

 

[Eva]

Don't worry, with 0.4ohms DCR the resulting filter will be very well damped.

 

[Tweeker]

This calculator will give you inductors approximating "perfect lay" designs.

When choosing your magnet wire to wind inductors be sure to keep Amps squared * Resistance = watts dissipated in mind, they are going to get hot.

With 7.5 amps bias and .4 ohms DCR in an AX 100 you'd be looking at ~30 watts dissipated in each inductor.

 

[jacco vermeulen]

in case you haven't found the link to Duncan's critter for fiddling CRC's yet:

http://www.duncanamps.com/psud2/index.html

 

[freakyone]

hello!

Ive already found that link Jacco but unsure of the values I should be using, maybe someones got a template I can use!!!

I have another question....
Finding a 600va 18-0-18v for my mono is impossible in this country and shipping one from Austrailia is not a option I want to use yet...Instead I found this pic from Kristijan k which I would use two 300VA 18-0-18v, parallel up the primary and then either just parallel the secondaries before going into the two bridge rectifier.....

Or as the pic shows having the secondaries each going into a bride rectifier (four Bridges per mono) first then parallel them up..

So my Question... Whats your thought on this????????????

Cheers
Dan

 

[freakyone]

--

 

[sss]

imho there is no point using extra bridges , i thing the traffos will work better in paralell directly (i hope u are using identical trafo's)

when paralelling the secondaries make sure the're in the same phase or else

 

[Eva]

It would probably work beter and be more reliable when the secondaries of each transformer are paralelled and used to drive a single diode bridge. I mean using each transformer to power one of the supply rails.