Engineering Calculate the Resistance of the RC circuit so that LED just stays on

AI Thread Summary
To calculate the resistance needed for an RC circuit with a 12V supply, a 12μF capacitor, and a 2V drop LED with a maximum current of 30mA at a frequency of 10Hz, the capacitive reactance (Xc) is calculated as approximately 1326.3 Ω. The power required for the LED is determined to be 0.36W. The discussion highlights the challenge of working with a low-frequency AC source, which complicates the calculations. The original poster expresses confusion about the next steps in solving the problem. The conversation emphasizes the complexities of AC circuit analysis, particularly with unusual battery frequencies.
rhiannynd
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In a simple series circuit there is a 12V supply battery, 12μ6 F capacitor, a Resistor, and a 2v drop LED with an imax of 30mA. frequency is 10Hz
Calculate the resistance of the resistor so that the LED just stays on.

Homework Equations


Resistance of Capacitor Xc = 1/2∏fC
P=VI
V=IR
Impedence = √R^2+Xc^2



The Attempt at a Solution



Xc = 1/2∏x10x12x10^6
=1326.3 Ω
P=vxI
P = 12 x 0.03A
=0.36w

i have no idea what else to do ! any help would be greatly appreciated please please please
 
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A battery with 10 Hz? That's a new one on me.
 
So, is Rhian (PS: welcome to PF) out of trouble now ?
 
BvU said:
So, is Rhian (PS: welcome to PF) out of trouble now ?

He/she doesn't seem interested in pursuing this fascinating ac battery problem, all the 'please pleases' notwithstanding ...
 

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