Author Topic: Using Capacitors to release a large amount of current  (Read 394 times)

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Offline vipulan12Topic starter

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Using Capacitors to release a large amount of current
« on: March 02, 2013, 05:47:08 PM »
Hey guys, I am kinda confused with capacitors
I get they store charge until it closes the current and once the battery is removed it acts like a battery and releases power but, how much current(amps)?
say i were to create a powerful magnetic field would i use capacitors?

Offline jwatte

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Re: Using Capacitors to release a large amount of current
« Reply #1 on: March 02, 2013, 07:39:32 PM »
The current is dependent on the resistance of your load, and the equivalent series resistance (ESR) of the capacitor.
Ceramic capacitors have very low ESR and thus can generate very high current. Electrolytic capacitors, however, have very high ESRs -- an ohm or more! -- and thus won't be very good at generating very high currents.
Also, as the current is driven by the capacitor, the voltage across it drops (because the charge dissipates) and thus the current will follow an exponential decay curve.

There are plenty of good references about capacitors, current, and charge (and Ohm's law, and differential equations, and inductors) on the web -- you probably want to find one or two and read through them until you understand them and can do the math that they describe on your own. Electronics is 50% math...

Offline vipulan12Topic starter

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Re: Using Capacitors to release a large amount of current
« Reply #2 on: March 03, 2013, 10:37:36 AM »
What do you mean by ESR or electrical series resistance?

Offline waltr

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Re: Using Capacitors to release a large amount of current
« Reply #3 on: March 03, 2013, 02:53:57 PM »

Offline Billy

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Re: Using Capacitors to release a large amount of current
« Reply #4 on: March 04, 2013, 04:32:54 PM »
say i were to create a powerful magnetic field would i use capacitors?

If you want to build a rail gun, yes, capacitors can be used. If you want to build one that works, you'll need high voltage to drive enough current, and high voltage capacitors get expensive quickly.  Good luck.

 


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