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Relationship of a capacitator network: series vs. parallel in an AC system?

Quick question: Do capacitors function the same in an AC system as they do in a DC system? Parallel vs. Series?

I presume impedance, however what about Volt Amp dynamics and capacitance? AC vs DC?

The reason I ask, I'm getting my costume ready for Halloween, outfitted with Electroluminescent wire which function as AC capacitors. Prior to soldering this system together with my battery pack and driver, I wanted to make sure I don't fry the copper anode lining the cables, or perhaps draw too much impedance / create destructive wave forms accidentally.

Update:

I understand EL Wires run on AC. I would like to know the dynamics of wiring them in series vs parallel. Thus the question regarding the difference of a capacitor networks in an AC system.

As for impedance / destructive waves would be a concern in any AC system, especially one sensitive to wave form and cycle rates.

Update 2:

For clarification: All wires DO NOT function as capacitors, only EL wire because of the two cable coaxial construction. This is well known for two plates separated with AC, but never singular wires, that's where impedance comes in.

Please don't answer this question unless you have an Electrical Engineering / Electrical Physics background...

2 Answers

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  • s
    Lv 7
    8 years ago
    Favorite Answer

    Capacitors and Inductors are FREQUENCY dependant REACTIVE devices, therefore with a DC source, there is no frequency and have no reactive term.

    With AC their reactance is dependant on the frequency and the relationship to frequency.

    For capacitors, reactance is INVERSELY proportional to frequency, therefore as frequency goes up, the reactance goes down.

    For inductors, reactance is DIRECTLY proportional to frequency, therefore as frequency goes up, the reactance goes up.

    Both store energy, capacitors store an electric field, whereas inductors store a magnetic field.

    Capacitors resist the change in voltage, whereas inductors resist the change in current.

    see ELI the ICE man.

    http://hyperphysics.phy-astr.gsu.edu/hbase/electri...

    Finally inductive and capacitive reactances will cancel each other out.

    For practical components all capacitors have some small inductance, and all inductors have some small capacitance. This is why their frequency plots are non-linear. Also real wire also has both small parts of inductance and capacitance, as well as resistance (per foot) , depending on the construction of both the individual wire and how it is bundled with other wires.

    The EL wire is specially constructed to have high capacitance on the phosphor coating seperating the core wire and the helical electrode (similiar to a vacuum tube or LED). This EL capacitor is designed to be lossy with an dielectric that radiates photonic energy. Almost like a controlled arc.

    For your design, what is your AC operating frequency ? Most EL backlighting uses from 60 to 400 Hz as the source voltage frequency. Is yours higher ? I noticed that the link from the other poster mentions 1 KHz. Also what is the operating voltage ? Typically EL works best at higher voltages. Again the link mentions 90 to 120 VAC.

    If you are using batteries, you cannot power the EL directly since batteries are DC, not AC sources. To generate AC you will need to use a DC to AC converter called an INVERTER. The inverter for these wires appear to be inverters and voltage regulators in a small box. So you may need multiple boxes, depending on how many EL loads each box can handle. The manufacturer should call this out for either total EL capacitance or usage time dependant on the loads used.

    You can calculate the capcitive reactance from XC = 1 / (2 * pi * freq * C) and then determine your loading for your wired configuration. The XC is in ohms so you can calculate the current draw based

    All resistors, capacitors and inductors add the same as configured, regardless of the sources. typically if you want a uniform load on each part, you want them in parallel, but this consumes more current. Remember that the capacitors will act as reactive elements (frequency dependant resistors).

    You may want to sketch out what you have and then present your questions about the configuration. That would be easier to critique your design. And make recommendations.

    Source(s): vast engineering experience.
  • 8 years ago

    Electroluminescent wire may function as a capacitor, as does any wire.

    Electroluminescent wire requires AC voltage to function, it will not work on DC such as batteries supply.

    "perhaps draw too much impedance / create destructive wave forms accidentally" Those are totally meaningless statements.

    "I presume impedance, however what about Volt Amp dynamics and capacitance?" ditto.

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