Inductor or Ballast: What Does Choke Mean?

[monus76]

hi there
i just need to know , we use ballast of fluorescent lamp or ( inductor) in series ,i know it chokes the current ,so i just need to know what that choke means,does it increase the value of current ( means to say does it increase the charge transfer per unit time) or does it means it change the frequency or why not we use step up or step down transformer in parllel to supply rather that choke coil in series.

i know my question is little big,but i really appeciate if someone reply.

with thanks

 

[Bob S]

For ac currents, inductances (chokes) limit current in a fashion vaguely similar to resistors, but without the resultant power loss and heating. If you have a choke of 100 millihenrys in a circuit at 60 Hz (w= 2 pi 60 = 377 radians per second), the voltage drop at 1 amp is
V = jwL I = j 377*0.1*1 amp = j 37.7 volts.
The "j" indicates a phase shift of 90 degrees because chokes represent a reactive load instead of a resistive load. If you put this choke in series with a 25 ohm resistor, the impedance magnitude is
!Z! = sqrt(37.7² + 25²) = 45.2 ohms

 

[oswaler]

Hi there,

Great question! A choke, also known as an inductor or ballast, is a type of electrical component that is used to regulate the flow of current in a circuit. It is typically made up of a coil of wire, which creates a magnetic field when current flows through it. This magnetic field resists changes in the current, effectively choking or limiting its flow.

To answer your question, the choke does not increase the value of current. Instead, it helps to regulate and stabilize the current by limiting its flow. This is important in fluorescent lamps because too much current can cause the lamp to overheat and potentially burn out.

As for why we use a choke coil in series rather than a step-up or step-down transformer in parallel, it is because the choke serves a different purpose. A transformer is used to change the voltage level of a circuit, whereas a choke is used to regulate the current. Additionally, using a transformer in parallel would not provide the same level of current regulation as a choke.

I hope this helps to clarify the purpose and function of a choke in a circuit. Let me know if you have any other questions. Happy experimenting!