| dytln_02 |
Anyone has try using mixed caps from many different brand ????
is there any side effect using mixed caps ? |
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| v-bro |
| Do you mean for buffering? For buffering it shouldn't matter much I think...the different charge/discharge characteristics will also be buffered always resulting in less ripple.... |
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| jamesrnz |
well
what are you going to use them for?
low freq bulk filtering not much difference.
high freq bulk buffereing, a pile of problems could occur. esr characteristics, longer leads resulting in current loops, inductance, oscilations all kinds of stuff.
of course i am a neophyte at the hi freq stuff. |
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| dytln_02 |
This psu for usb soundcard using sulzer borbely Regulator ???
Caps before LM 317 mixed from different brand..(4x470uF)
I Have try using elna cerafine caps (has been burn-in) but sound coming from this soundcard is too soft and boomy bass.., Using Nippon Chemicon Cap (has been burn-in) give bright sound...
how about mixed this caps ??? |
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| jamesrnz |
so you have a linear regulator.
the bulk caps should not have an effect regardless of manufacturer., however the total capacity may be too low. i have found the best is large caps on both the input and output of the lm317 as well as .001,.01,.1 also on input and output. close to i/o pins and ground.
what are you input and output voltages?
the lm317 is good for 1-1.5 amp depending on the manufacturer.
4x470uf is over kill for for a lm317 those caps are probably in a different part of the circuit. and does not probably have anything to do with the lm317......
need more info |
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| dytln_02 |
Input voltage is 9 v from transformer
Output voltage is 5v
Schematic is sulzer borbely (change op-amp with JRC4556AD).
this layout that I use, I only use 4x470uF/16v and 0.1uF Wima MKS2 before LM 317. Voltage Reference LM336z 2.5v , using dual op-amp JRC4556AD.
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| jamesrnz |
have you monitored the waveforms of the input and output of the lm317 and the bd241? while you are playing music?
what is r3 and r4?
i am wondering if the opamp change and divider and reference diode that is changed have change the feedback of the emitter follower. |
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| dytln_02 |
| quote: | Originally posted by jamesrnz
have you monitored the waveforms of the input and output of the lm317 and the bd241? while you are playing music?
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I don't have osciloscope :bawling:
| quote: | Originally posted by jamesrnz
what is r3 and r4?
[/B] |
It's the same as original value R3=47K and R4=10K.
I don't know how to calculate value for R3 and R4. (I'm not EE)
can you give reference so i can learn.
I have try many op-amp (NE5532AP, OPA2134PA, JRC4558D, JRC4556AD, AD8620, OPA627, THS4032) each op-amp will give different sound. JRC 4556AD give the best sounding in my opinion.
I have try with original schematic using NE5534 (different pcb layout) only change LM336Z 2.5v , change one 470uf with other brand will give different sound. |
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| dytln_02 |
sorry last time I write wrong.
My Value for
R3 = 500
R4 = 1K
R6 = 47K
R7 = 10K
Now use this value
R3 =1.2k
R4 = 2.4k
R6 = 47K
R7 = 10K
Bass now is better
this one I don't understand, is this correct
R6 = R3 || R4 for this psu
How to calculate R6 and R7. |
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| jamesrnz |
ok,
assuming 5 volt output,
====== lm317 ======
Vin should be at least 2v higher than Vout at max draw
Vout = 1.25(1 + R1/R2)
Vout=5v
Vin=10v
r1=~450
r2=120
========opamp=========
non inverting dc amp, the specs of the ic's you used are not far from the specified ic so the ic shouldn't be much of an issue.
Vout/Vin=Av=1+r4/r3
r4a=1000
r3a=500
Av=2
r4b=2400
r3b=1200
Av=2
both of the amps gain are 2 at DC, however, the Xc resonance is changed when AC component is added,varying load.
4.7uf with 1000 is 212hz
4.7uf with 2400 is 88hz
by changing the feed back resistor r4 you have changed how the emitter follower responds to varying loads which can have an effect on the amplifier response. since the usb amp should only draw i believe about a max of 100 ma this should not be much of a problem.
r6 and c6 have aresponse of of about 21 hz which is about a 10:1 ratio from the feedback rolloff rc.
========voltage refeance========
however,
you have also changed the reference voltage from 5 volts to 2.5 volts
the Lm336-2.5 should have an operatirng currrent of 400ua to 10ma, so....
Iser=Zref/r7
i think the r7 a 10k is too large and the zener will not regulate well since it supplies the voltasge reference for the op amp through r6.
you need something in the range of 2500, at 10k with 5 volt the zener is operating at 250ua and should be a minimum of 400ua so something in the order of 2500 to 5000 ohms for r7 would be better.
the combination of r6 and c6 set the reference response for the opamp. with the rference from the zener being low the opamp reference will flutuate with load and cause the emitter follower bias to fluctuate and the output voltage of the regulator will vary with load.
i would consider a signifcantly larger c7 to buffer the load say 470uf to 470ufx2.
In short put r4 and r3 back to 1000 and 500, reduce r7 to 2500 and increase c7 to 470uf.
changing the caps and resistors in the regulator and seeing a change in the response of the amp indicates poor regulation.
a scope would really help you see how things are working. |
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| dytln_02 |
With r4=1000 , r3 = 500, r7 = 2500 and c7 =470uf.
with mixed caps or not, now my sound card sound very similar.
I Have buy Lead Acid battery, compare with regulator gives similar sound too...(but is better using lead acid battery)
Now, I think this regulator working correctly.
Thank you very much. |
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| jamesrnz |
well cool!
without a scope you could spend hours and hours fine tuning by swapping parts to get it sounding like a battery.
my suggestions were just textbook starting points.
i don't know your finances but i see $100.00us scopes on ebay that get to 100mhz, which would cover you for most things if you get into switching supplies. however, if you stay with analog a 10 or 20 mhz would more than suffice.
when i started playing with smps i had to get a 100 mhz scope i saw all kinds of stuff that was bad going on.
there are a few people on the board eva, n-channel, chocoholic, cerram, poobah and some others that do not come to mind who have invaluable experience with smps. |
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| dytln_02 |
thanks but , shipping cost to my country is about $150 that make me crazy...:mad:
may be another time i will buy a scope. |
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| ridwans |
Hallo .
sorry for my english, my english is so bad.
bro i want to ask
cant i change ic regulator / and output transistor bc241 with higher current like TIP2955
and increase current LM317 with TIP2955/ with Pass Transistor.
it could work?
is the performance of regulator is down?
thx for your time.
please help me.
i plant to use the regulator for build 5V reg and 12V reg for playing cd ASUSX52
need 5V 1.2A and 12V 1,5A
this is the schematic and the pcb
when i use it....
bd 241 is hottt. and lm 317 tooo event 1 change it with medium high sigh.
the condition is still out casing.
need advice everyone.
thx |
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| ridwans |
Plant to use 2 pcb
1 5V
1 12V |
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