Hi,
just a small question besides this discussion (and a big HI to JeanPaul!)
I'm planning to build a power supply to feed 3 4th order crossovers. (that means driving 24 single opamps) The idea is to build this powersupply:
http://hitechnetworks.net/bwaldron/audioelectronics/sb1_regulator.htm
Since the standard 4700µF capacitors have a rather large impedance, I planned to replace each 4700µF capacitor (that are C15, C16, C21, C22 in this schematic) with 4 United Chemicon SXE 470µF/50V capacitors in parallel.
The capacitiance is 40% of what the schematic says, but the ESR of those parallel capacitors is WAY lower than with one 4700µF, and the max ripple current is about 2 times as high.
Is this a good idea to do?
Grtz, Joris
P.S. The specs of the 470µF SXE's: 0.068 Ohm maximum impedance at 100kHz (20 degr C.) Maximum ripple current at 100kHz (105degr C.) is 1320mA
just a small question besides this discussion (and a big HI to JeanPaul!)
I'm planning to build a power supply to feed 3 4th order crossovers. (that means driving 24 single opamps) The idea is to build this powersupply:
http://hitechnetworks.net/bwaldron/audioelectronics/sb1_regulator.htm
An externally hosted image should be here but it was not working when we last tested it.
Since the standard 4700µF capacitors have a rather large impedance, I planned to replace each 4700µF capacitor (that are C15, C16, C21, C22 in this schematic) with 4 United Chemicon SXE 470µF/50V capacitors in parallel.
The capacitiance is 40% of what the schematic says, but the ESR of those parallel capacitors is WAY lower than with one 4700µF, and the max ripple current is about 2 times as high.
Is this a good idea to do?
Grtz, Joris
P.S. The specs of the 470µF SXE's: 0.068 Ohm maximum impedance at 100kHz (20 degr C.) Maximum ripple current at 100kHz (105degr C.) is 1320mA
A big HI to you too Joris ! The idea of replacing the 4700 uF caps for 4 x 470 uf just for very low ESR makes not much sense. In ripple calculations the capacitance value is the one you're calculating with unless you're dealing with a switcher.
So you have to know how much current your 24 opamp crossover will draw. Then use the rule of thumb ( or look up the formula if you wish ) that one 2200 uF will suffice for 1A of current draw. Now calculate how many 470 uF SXE you need before the regulators. I am confident 4 x 470 uF will suffice with modern opamps. Nevertheless calculate things. Why not use 8 x 470 uF if you have them ?
But... I wouldn't use low ESR caps *after* the regulators.
BTW we are threadjacking.
Jean-Paul/ who hopes Jan Didden is around for a theoretical backup.
So you have to know how much current your 24 opamp crossover will draw. Then use the rule of thumb ( or look up the formula if you wish ) that one 2200 uF will suffice for 1A of current draw. Now calculate how many 470 uF SXE you need before the regulators. I am confident 4 x 470 uF will suffice with modern opamps. Nevertheless calculate things. Why not use 8 x 470 uF if you have them ?
But... I wouldn't use low ESR caps *after* the regulators.
BTW we are threadjacking.
Jean-Paul/ who hopes Jan Didden is around for a theoretical backup.
Sorry I can't give a direct link, because when you go th theyr website, you are "logged", your url ends with a session id, and is invalid after some minutes of inactivity. That sux
www.radiospares.fr
on the left menu: "actifs et passifs", then "condensateurs", "aluminium", "polarises", and on the 3rd page you have 3 types of OSCONS.
Tell me what you think of theyr prices
www.radiospares.fr
on the left menu: "actifs et passifs", then "condensateurs", "aluminium", "polarises", and on the 3rd page you have 3 types of OSCONS.
Tell me what you think of theyr prices
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