choke coils
- Thread starter jcblythe
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scott thompson
Senior Member
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- Anaheim, California
Re: choke coils
A "Choke" is an Inductor (or Reactor Cores - such as used to Ballast Discharge Lamps), which both stores energy (Reactive power, or VARs) and opposes changes in current levels (current levels changing sounds like an Oxy-Moron, doesn't it???
...). The term "Reactor" is used here, instead of "Choke".
Lamp de-buzzing using a series Reactor is done in conjunction with "chopped wave" dimming controls, which smoothes out the "bursts" of energy reaching the Incandescent Lamp's Filament. The series Reactor functions (basically) like a parallel connected Capacitor would (think towards the DC filter on the load side of a Rectifier).
Reactors (chokes) are also used in filtering (band pass, low pass, high pass, etc.) and similar applications.
The filter networks (low pass, etc.) may be for rejecting Harmonics, filtering an AC input (RFI filtering), or for "Crossovers" on Audio System Speakers (low pass to woofer, band pass to midrange, high pass to tweeter).
Also used to "stop" an imposed signal from either reaching some sensitive equipment, or leaving a building.
An example for keeping an AC carrier wave power circuit signal from leaving the building and venturing outwards to other PoCo customers would be the "Auto Time Catch Up" functions for Clocks in Schools.
About 2 or 3 minutes prior to each hour, the clock(s) will run fast and stop at the next upcoming hour, wait for a certain time, then start running again.
The only connection to the clock(s) is the 2 wire 120 VAC circuit.
The 60Hz AC power circuit carries the clock control information (the 60Hz is the carrier wave).
To keep this from leaving the building on the AC supply, chokes are installed at the service (or subpanel(s) if premesis is fed via higher than 120 VAC system).
Reactors are very interesting creatures! Just ask Bennie about Saturable Reactors and Mag. Amps!
Scott35
p.s. had to edit some bad spelll-llingg! Itss fikxed noww! (I hope )
S.E.T.
[ September 28, 2003, 06:34 PM: Message edited by: scott thompson ]
A "Choke" is an Inductor (or Reactor Cores - such as used to Ballast Discharge Lamps), which both stores energy (Reactive power, or VARs) and opposes changes in current levels (current levels changing sounds like an Oxy-Moron, doesn't it???
...). The term "Reactor" is used here, instead of "Choke".Lamp de-buzzing using a series Reactor is done in conjunction with "chopped wave" dimming controls, which smoothes out the "bursts" of energy reaching the Incandescent Lamp's Filament. The series Reactor functions (basically) like a parallel connected Capacitor would (think towards the DC filter on the load side of a Rectifier).
Reactors (chokes) are also used in filtering (band pass, low pass, high pass, etc.) and similar applications.
The filter networks (low pass, etc.) may be for rejecting Harmonics, filtering an AC input (RFI filtering), or for "Crossovers" on Audio System Speakers (low pass to woofer, band pass to midrange, high pass to tweeter).
Also used to "stop" an imposed signal from either reaching some sensitive equipment, or leaving a building.
An example for keeping an AC carrier wave power circuit signal from leaving the building and venturing outwards to other PoCo customers would be the "Auto Time Catch Up" functions for Clocks in Schools.
About 2 or 3 minutes prior to each hour, the clock(s) will run fast and stop at the next upcoming hour, wait for a certain time, then start running again.
The only connection to the clock(s) is the 2 wire 120 VAC circuit.
The 60Hz AC power circuit carries the clock control information (the 60Hz is the carrier wave).
To keep this from leaving the building on the AC supply, chokes are installed at the service (or subpanel(s) if premesis is fed via higher than 120 VAC system).
Reactors are very interesting creatures! Just ask Bennie about Saturable Reactors and Mag. Amps!
Scott35
p.s. had to edit some bad spelll-llingg! Itss fikxed noww! (I hope
)S.E.T.
[ September 28, 2003, 06:34 PM: Message edited by: scott thompson ]
Re: choke coils
In the simplest of terms it is just a coil of wire or an inductor. It is a.k.a. ?high pass filter?. Any conductor exhibits inductance. The effects are amplified by winding the wire in a coil fashion and further amplified by winding around a ferrous material such as iron as is done in transformers.
The math behind it is simple. (Z = 6.28 * F* I)
Where:
6.28 = 2 * 3.14 = 2Pie
Z = impedance
F = Frequency
I = Inductance
As you can see if you increase Frequency or the Inductance the impedance (Z) rises. which forms a ?high pass filter? or "choke".
This can be an advantage or disadvantage.
[ September 28, 2003, 09:53 PM: Message edited by: dereckbc ]
In the simplest of terms it is just a coil of wire or an inductor. It is a.k.a. ?high pass filter?. Any conductor exhibits inductance. The effects are amplified by winding the wire in a coil fashion and further amplified by winding around a ferrous material such as iron as is done in transformers.
The math behind it is simple. (Z = 6.28 * F* I)
Where:
6.28 = 2 * 3.14 = 2Pie
Z = impedance
F = Frequency
I = Inductance
As you can see if you increase Frequency or the Inductance the impedance (Z) rises. which forms a ?high pass filter? or "choke".
This can be an advantage or disadvantage.
[ September 28, 2003, 09:53 PM: Message edited by: dereckbc ]
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