Topic: Bypass capacitors in the power supply

[JojoD818]

Me and monreq used to play with different caps like polypropelene, polystyrene and silver mica. Also we experiment putting them in series then putting these caps in parallel with the e-cap. This approach may work for some that is why I want to mention it here.

I have to admit that in my years as a hobbyist that this is the first time that I have ever heard of series bypass caps...

Sometimes instead of bypass cap I just put high value resistor in parallel with e-caps. E-caps are really notorious as it takes very long time for them to discharge.

I believe the term is bleeder resistor. It is intended to slowly discharge the e-caps when powered down. I sure hope you are not saying that the resistor would improve the performance of the power supply.

Resistors are much faster than small value polyester, polypropelene, polystyrene and silver mica.

You really lost me here... 

[JojoD818]

It's always a bad idea for me to wake up early and check emails and threads... now I can't go back to bed... 

too bad it's "bed weather" outside... 

[qguy]

On the Bleeder Resistors..

1. Why do you need to discharge the capacitor ? 

2. wouldnt that get overly hot when the amp is being used as it is  continually being bombarded with current ?

3. Since its connected during operation, then it would act like a parasite eating away current during normal operation ?  Ok sana kung naka "on"  yung resistor when the AMP is off.

[Stagea]

On the Bleeder Resistors..

1. Why do you need to discharge the capacitor ? 

2. wouldnt that get overly hot when the amp is being used as it is  continually being bombarded with current ?

3. Since its connected during operation, then it would act like a parasite eating away current during normal operation ?  Ok sana kung naka "on"  yung resistor when the AMP is off.

1. Mostly for safety purposes
2./3. The right resistor value would not waste too much energy during operation (and thus won't heat up a lot), but will also discharge the cap/s fast enough after use.

[JojoD818]

On the Bleeder Resistors..

1. Why do you need to discharge the capacitor ? 

2. wouldnt that get overly hot when the amp is being used as it is  continually being bombarded with current ?

3. Since its connected during operation, then it would act like a parasite eating away current during normal operation ?  Ok sana kung naka "on"  yung resistor when the AMP is off.

1. The energy stored in a capacitor can be dangerous if not discharged properly.

2. No, the resistance value and wattage of the resistor is chosen particularly to eliminate that problem.

3. Yes, but the current that flows through it is so small that making a circuit that removes it when powered on and puts it back in-circuit when the amp is switched off is not impossible to do but somewhat impractical. Manufacturers and designers mostly follow the rule KISS as much as possible.

[ATJr.]

On the Bleeder Resistors..

1. Why do you need to discharge the capacitor ? 

2. wouldnt that get overly hot when the amp is being used as it is  continually being bombarded with current ?

3. Since its connected during operation, then it would act like a parasite eating away current during normal operation ?  Ok sana kung naka "on"  yung resistor when the AMP is off.

very good questions......

1. under normal operations, you don't, the power amp will discharge those caps in no time at all once you hit the power switch to off position....but stagea is correct, for safety reasons it is better to use bleeders...

2. in the super leach  power amp i posted, i used a 4.7k 2 watt bleeder resistor, so at idle, the resistor dissipates [85^2]/4700 = 1.5 watts, under full load when the voltage sags to 72volts, the bleeder resistor dissipates [72^2]/4700 = 1.1 watts, so the bleeder actually cools down under load....

3. using my super leach amp as an example, at idle, the bleeder resistor draws 85v/4700 = 0.018mA, the amp itself is biased to draw 150mA at idle, so here you will see that 18mA is <<< less than 150mA...
at full load, the the bleeder resistor draws 72v/4700 = 0.015mA, the amp itself draws 45/8 or 5.65A again way way lower 15mA <<<< 5650mA

so you see there are reasons why we do things in an amplifier.....

my take on bypass and caps, whatever you can afford, whatever gives you satisfaction, use them, it is the right cap for you....

[ATJr.]

I have to admit that in my years as a hobbyist that this is the first time that I have ever heard of series bypass caps...

I believe the term is bleeder resistor. It is intended to slowly discharge the e-caps when powered down. I sure hope you are not saying that the resistor would improve the performance of the power supply.


You really lost me here... 

asa ka pa, nakaimbento nga ng "magic coils" eh gasino na yung caps.... do not expect scientific explanations.....basta kung ano sinabi yun na....

[rascal101]

I have to admit that in my years as a hobbyist that this is the first time that I have ever heard of series bypass caps...



I believe the term is bleeder resistor. It is intended to slowly discharge the e-caps when powered down. I sure hope you are not saying that the resistor would improve the performance of the power supply.



You really lost me here... 

Resistors do not retain charge like caps do.  I specifically mentioned speed up charging and discharging. Please read my post fully. Paano ba pabilisin pa kung hindi na pwede liitan un e-cap at may bypass cap ka na? Please enlighten me.

Putting caps in series then paralleling these to another cap? This cannot be done? Why?  Masisira un cap?

@tonyt I have never said magic. This came from another person.  Init pa rin ulo mo? Atakihin ka na niyan.

[ATJr.]

Resistors do not retain charge like caps do.  I specifically mentioned speed up charging and discharging. Paano ba pabilisin pa kung hindi na pwede liitan un e-cap at may bypass cap ka na? Please enlighten me.

Putting caps in series then paralleling these to another cap? This cannot be done? Why?  Masisira un cap?

@tonyt I have never said magic. This came from another person.  Init pa rin ulo mo? Atakihin ka na niyan.

here:
http://www.google.com.ph/search?q=rc+time+constants+calculator&aq=1&oq=rc+time+constants&sugexp=chrome,mod=9&sourceid=chrome&ie=UTF-8

and i never mentioned "rubbish" until someone mentioned it, there, quits na tayo.....

[rascal101]

Sige quits na tayo. Debate na lang tayo sa resistor na nilagay ko at sa pag series ko ng caps. Magandang talakayan. Suggest ko lang huwag mo ng gamitan ng links mga post mo. Ilang clicks din iyon. I explain mo na lang at marunong ka naman. Moderator ka pa naman kaya alam ko kayang kaya mo.

[shrek7]

Well, my take on this matter is, dont be afraid to try new things. Im someone who doesnt have technical background but keeps an open mind everytime i hear suggestions from people who have more experience than me.  Medyo magastos nga lang, but still i was able to learn and compare those suggestions, one by one. Ive tried a lot of bypass caps on different amps, tube, ss, t-amps, even my dac. Even tried bypass caps on series, which ive not heard or read about in any thread in the internet, but it sounds good to me.

We have different personalities, others sticks by the book and all the theories/standards the electronic/electrical world has to offer, some would like to do experiments and deviate from the standards, and some listen to both (me) without considering whether its logical or not, only caring about how  it sounds. So, i guess, what readers like me are looking for are the real world suggestion that you have tried and your impression of how it sounds and what improvements that you have heard. So please give a suggestion and impression of something that you have tried and then back it up with technical explanation later. Im not looking for someone who is better or brighter than the other, but someone who gives suggestion regarding the matter. Sensya na im just someone who reads most of the gurus posts if not all their posts. So please make this discussion worthwhile. 

[markcrenz]

Resistors do not retain charge like caps do.  I specifically mentioned speed up charging and discharging. Please read my post fully. Paano ba pabilisin pa kung hindi na pwede liitan un e-cap at may bypass cap ka na? Please enlighten me.

kahit anong value ilagay na resistor in parallel with a cap, you cant change the charging speed of a capacitor unless you change the series resistance. kaya nga RC time constant ang tawag.
pabilisin? di nga pwede kung di liliitan ang cap. key word: constant.

Putting caps in series then paralleling these to another cap? This cannot be done? Why?  Masisira un cap?

i sure hope you meant putting a cap in series with a resistor (RC snubber) then putting it in parallel with the other cap. just putting a cap in series to a psu will simply create a high pass filter.

[JojoD818]

Resistors do not retain charge like caps do.  I specifically mentioned speed up charging and discharging. Please read my post fully. Paano ba pabilisin pa kung hindi na pwede liitan un e-cap at may bypass cap ka na? Please enlighten me.

I know what you post, I got lost really. No resistor can speed up charging time, not even in a rc time constant. It can speed up discharge time of course.

Putting caps in series then paralleling these to another cap? This cannot be done? Why?  Masisira un cap?

I didn't say it cannot be done. All I said is this would be the very first time I would see it. Plus the notion of connecting a polyprop in series with a silver mica then using that as a bypass is truly unheard of.

[JojoD818]

asa ka pa, nakaimbento nga ng "magic coils" eh gasino na yung caps.... do not expect scientific explanations.....basta kung ano sinabi yun na....

nawala ang antok ko kanina umaga...  hay...

[ATJr.]

Well, my take on this matter is, dont be afraid to try new things. Im someone who doesnt have technical background but keeps an open mind everytime i hear suggestions from people who have more experience than me.  Medyo magastos nga lang, but still i was able to learn and compare those suggestions, one by one. Ive tried a lot of bypass caps on different amps, tube, ss, t-amps, even my dac. Even tried bypass caps on series, which ive not heard or read about in any thread in the internet, but it sounds good to me.

We have different personalities, others sticks by the book and all the theories/standards the electronic/electrical world has to offer, some would like to do experiments and deviate from the standards, and some listen to both (me) without considering whether its logical or not, only caring about how  it sounds. So, i guess, what readers like me are looking for are the real world suggestion that you have tried and your impression of how it sounds and what improvements that you have heard. So please give a suggestion and impression of something that you have tried and then back it up with technical explanation later. Im not looking for someone who is better or brighter than the other, but someone who gives suggestion regarding the matter. Sensya na im just someone who reads most of the gurus posts if not all their posts. So please make this discussion worthwhile. 

it is not important to me how others perceive the sounds of their gears, kanila yon eh, kung saan sila masaya eh di pagbigyan ..........

imho what matters is what you hear on your gear, are you good?, are you happy? after all that is all that really matters..........not some anecdotes by cap changers..........

as a matter of principle i refrain from commenting on my own work, i let others make the comments, if they are happy and liked what they heard, then i am happy for them ........if they are not, i don't care .......i don't DIY so as to impress others..........i do it to please myself only......i really do not care .........

[ATJr.]

nawala ang antok ko kanina umaga...  hay...

ako man, nagpaalis din ng antok, kakagising ko din lang....

[JojoD818]

Well, my take on this matter is, dont be afraid to try new things. Im someone who doesnt have technical background but keeps an open mind everytime i hear suggestions from people who have more experience than me.  Medyo magastos nga lang, but still i was able to learn and compare those suggestions, one by one. Ive tried a lot of bypass caps on different amps, tube, ss, t-amps, even my dac. Even tried bypass caps on series, which ive not heard or read about in any thread in the internet, but it sounds good to me.

We have different personalities, others sticks by the book and all the theories/standards the electronic/electrical world has to offer, some would like to do experiments and deviate from the standards, and some listen to both (me) without considering whether its logical or not, only caring about how  it sounds. So, i guess, what readers like me are looking for are the real world suggestion that you have tried and your impression of how it sounds and what improvements that you have heard. So please give a suggestion and impression of something that you have tried and then back it up with technical explanation later. Im not looking for someone who is better or brighter than the other, but someone who gives suggestion regarding the matter. Sensya na im just someone who reads most of the gurus posts if not all their posts. So please make this discussion worthwhile. 

“The only thing necessary for the triumph of evil is for good men to do nothing.”

There is nothing wrong when you try new things, this is how new inventions and discoveries are made. But there are Laws of Physics that had been there for centuries as a guide or a road map for us to follow. Unless you are living in "The Matrix", these Laws cannot be bent or broken.

The problem with the discussion usually starts when these Laws are bent and neglected because the doer was so convinced that what he did made a big difference in sound and that he can hear it. Even explaining it and recommending it to others.

Personality has nothing to do with this. Book, or theory, or actual it's all going to be the same as long as we are governed by the same Laws of Science.

Doctors need to study new ways of operating on a patient or a new drug. Lawyers need to be abreast with the latest Laws of the land. Keep an open mind?

[JojoD818]

ako man, nagpaalis din ng antok, kakagising ko din lang....

ang aga ko nagising, check lang dito at sa kabila... buti nakatulog ako ulit... 

[rascal101]

kahit anong value ilagay na resistor in parallel with a cap, you cant change the charging speed of a capacitor unless you change the series resistance. kaya nga RC time constant ang tawag.
pabilisin? di nga pwede kung di liliitan ang cap. key word: constant. i sure hope you meant putting a cap in series with a resistor (RC snubber) then putting it in parallel with the other cap. just putting a cap in series to a psu will simply create a high pass filter.

Nababawasan iyung effective resistance in series sa bulk cap kaya nag-improve iyung charging time. Slightly nga lang gaya ng nasabi ko kamakailan.

Naka parallel sa bulk cap iyung capacitor kaya low pass filter iyun. Hindi ba bypass cap ang pinag-uusapan natin. Masita ka ni Sir tonyt niyan.

[rascal101]

I know what you post, I got lost really. No resistor can speed up charging time, not even in a rc time constant. It can speed up discharge time of course.

I didn't say it cannot be done. All I said is this would be the very first time I would see it. Plus the notion of connecting a polyprop in series with a silver mica then using that as a bypass is truly unheard of.

Kapag bumaba iyung R hindi mag-improve iyung charging time? Sabi nga ni Sir markrenz kailangan daw ibaba iyung series resistance. Ano ba talaga Sir?

Kung walang mali technically anong problema kung nag-series ako ng polystyrene at silver mica? Type ko at meron naman ako. Gusto ko mag-experiment para maiba naman.

E kayo Sir kasi madalas kayo mag DIY so anong approach niyo? Baka may suggestion kayo sa klase ng cap na gamit niyo tapos paano niyo kino compute if ever.

[rascal101]

it is not important to me how others perceive the sounds of their gears, kanila yon eh, kung saan sila masaya eh di pagbigyan ..........

imho what matters is what you hear on your gear, are you good?, are you happy? after all that is all that really matters..........not some anecdotes by cap changers..........

as a matter of principle i refrain from commenting on my own work, i let others make the comments, if they are happy and liked what they heard, then i am happy for them ........if they are not, i don't care .......i don't DIY so as to impress others..........i do it to please myself only......i really do not care .........

Kung saan ka masaya suportahan kita :-)

[markcrenz]

Naka parallel sa bulk cap iyung capacitor kaya low pass filter iyun. Hindi ba bypass cap ang pinag-uusapan natin. Masita ka ni Sir tonyt niyan.

ok navisualize ko na yung connections mo sa caps

Nababawasan iyung effective resistance in series sa bulk cap kaya nag-improve iyung charging time.

ito ang di ko pa rin magets at di maka-agree kahit kailan. hindi bababa yung series resistance dahil naka-parallel ang resistor. in this case kasi na wala naman actual resistor in series doon sa psu, ang series resistance ay internal series resistance lang ng capacitor, na di mababago kahit anong resistor i-parallel mo. so ang time constant eh product ng capacitance at internal resistance ng capacitor. yung sinasabi mong resistor in parallel will appear as a load na. gets?

[rascal101]

Hindi lang naman iyung esr ng bulk cap ang kino consider, meron din pcb trace resistance bago pa mag bulk. Kung maglalagay ako ng resistor na naka parallel sa bulk iyung magiging total resistance ay iyung computed resistance ng pcb trace at iyung esr then iparallel itong dalawa sa resistor. Mas mababa ang total resistance na ito.

[markcrenz]

Hindi lang naman iyung esr ng bulk cap ang kino consider, meron din pcb trace resistance bago pa mag bulk. Kung maglalagay ako ng resistor na naka parallel sa bulk iyung magiging total resistance ay iyung computed resistance ng pcb trace at iyung esr then iparallel itong dalawa sa resistor. Mas mababa ang total resistance na ito.

perhaps your buddies at diyaudio can help clarify yet another misunderstood electrical concept.

[ATJr.]

any discussions on the effects of the resistor is conjunction with a capacitor without application to an actual circuit is meaningless imho.....put up the circuit and we can analyse, otherwise..........discussions of theories without practical applications is tantamount to mental constipation.....

another gems from diyaudio for those technically inclined.....http://www.diyaudio.com/forums/power-supplies/192040-power-supply-bypass-cap-size.html and http://www.diyaudio.com/forums/solid-state/94240-bypass-caps-power-supply.html

[s2kov]

I overlooked this thread!

So hot here!

[shrek7]

“The only thing necessary for the triumph of evil is for good men to do nothing.”

There is nothing wrong when you try new things, this is how new inventions and discoveries are made. But there are Laws of Physics that had been there for centuries as a guide or a road map for us to follow. Unless you are living in "The Matrix", these Laws cannot be bent or broken.

The problem with the discussion usually starts when these Laws are bent and neglected because the doer was so convinced that what he did made a big difference in sound and that he can hear it. Even explaining it and recommending it to others.

Personality has nothing to do with this. Book, or theory, or actual it's all going to be the same as long as we are governed by the same Laws of Science.

Doctors need to study new ways of operating on a patient or a new drug. Lawyers need to be abreast with the latest Laws of the land. Keep an open mind?

well perhaps i believe, I live in the matrix. Laws of science changes when there are updates regarding the matter, by those people who are bold enough to try and bend the law.

[shrek7]

it is not important to me how others perceive the sounds of their gears, kanila yon eh, kung saan sila masaya eh di pagbigyan ..........

imho what matters is what you hear on your gear, are you good?, are you happy? after all that is all that really matters..........not some anecdotes by cap changers..........

as a matter of principle i refrain from commenting on my own work, i let others make the comments, if they are happy and liked what they heard, then i am happy for them ........if they are not, i don't care .......i don't DIY so as to impress others..........i do it to please myself only......i really do not care .........

good for you brader! I think thats what we should advocate here in pdvd. We should not care, we should only care for ourselves and satisfy ourselves alone and be happy. Nice! Thanks for the advise, i will really keep this in mind.

[rascal101]

perhaps your buddies at diyaudio can help clarify yet another misunderstood electrical concept.

Perhaps you can explain why you have misunderstood and said bypass caps prevent oscillations. And also explain why all of a sudden you said the bypass cap is a high pass filter.

[sound garden]

BEFORE

AND AFTER