Coursework help

[ceraunic_level]

Need some help with my 2330 course

Need to take several readings off this fluorescent circuit

Current whan capacitor is not in circuit and current when is in circuit

Then I need to take the supply voltage

Voltage across choke

Voltage across Lamp

Basically A1 (ammeter) shows less current when capacitor is swiched on

Question 1

Is the capacitor causing less amps to be pulled because it is a capacitive load and so the current leads the voltage, where as the choke is inductive and current lags the voltage. Thus the two together balance out, as it were, improving PF

Or does the capacitor return a charge which resists the supply voltage and current.

Question two

Why, When the voltage across the choke and lamp are added, they do not add up to the supply voltage ??

Would the voltage be more or less?

Is it bacause of parallel circuits choke and lamp in series, capacitor in parallel




Cheers

 

[Space cat]

Is the capacitor causing less amps to be pulled because it is a capacitive load and so the current leads the voltage, where as the choke is inductive and current lags the voltage. Thus the two together balance out, as it were, improving PF

That's a reasonable answer.

Why, When the voltage across the choke and lamp are added, they do not add up to the supply voltage ??

You have to use vectors when you add voltages (or currents) in reactive circuits. The two voltages are not in phase - the voltage in the coil leads the voltage in the lamp - so their vector sum will be less than the sum of their lengths.

Edit: I shouldn't call them vectors. The correct word is "phasor". As with a vector, the length represents amplitude but the angle represents phase angle rather than direction.

 

[ceraunic_level]

Thanks Space cat

 

[Space cat]

You're welcome.