Two capacitors in parallel - High or Low ESR?

[Ping]

Hi,
I want to put two capacitors in parallel in a DC circuit. I need the charging and discharging times to be as brief as possible. Should I get capacitors with high ESR or low ESR?

Thanks.

 

[Gryd3]

Hi,
I want to put two capacitors in parallel in a DC circuit. I need the charging and discharging times to be as brief as possible. Should I get capacitors with high ESR or low ESR?

Thanks.

How do you know of ESR? You should be able to answer this yourself

 

[Ping]

I'm teaching myself. Patchy background in physics.
I'm thinking high ESR, but I want to be sure before spending money.
Someone teach me!

 

[Colin Mitchell]

You actually want capacitors with high ripple current capability. This really means looking at the size and selecting the biggest capacitor for the capacity and voltage-rating that you choose. Ripple means how hot they will get when in use.

 

[Harald Kapp]

I need the charging and discharging times to be as brief as possible.

ESR = Equivalent Series Resistance. The ESR plus the capacitance form a low pass filter with time constant t=R*C.
See for yourself how the resistance (ESR) influences charging time.
Probably the factor limiting the charge current and thus charge time is not the ESR but the max. currrent you can draw from the charging circuit.

 

[(*steve*)]

For rapid charge and discharge ESL actually becomes important. Capacitors designed for use in xenon flash applications are an example of a capacitor designed to be discharged rapidly.

 

[supertech007]

Low esr

 

[supertech007]

the lower the esr the faster the dc dischage time