I am facing to calculate the current consumption in a segment of a circuit as shown in the picture below.I have used the formula (showed in the picture) without considering the impedance of the capacitor C1. I have just considered the resistors components. Can any one tell me if the formula that I have done is correct to determine the current consumption. Best regards,
Since the cap is across source Vac and not Vdc out, it is a rectified DC Voltage but no storage so the voltage is just a rectified sine but the current is not rectified as shown. (Looks like an drawing error)
We expect Ipk ~ 320V/50k= 6.x mA (Peak current)
Yes, you include Cap impedance, Zc=-j /2pifC =
-j318 -j31.8 kOhms shunting the 2nd term in the denominator, resulting in a phasor current.
With Vpk(AC)/Vf (diode) ratio being so small, you can neglect this, which only causes a small apparent crossover distortion of +/-1.2V in the current.
You can compute Thevenin equivalent voltage and source Zs’ (at Bridge then ignore it) for the AC analysis, then load current is V’/100k+(V’-Vzt)/100k for some threshold voltage Vzk since it is drawing a few mA where the ZK Zener Knee Voltage is rated in the datasheet.
How to do step 1? Like any serial-shunt divider, except use Zc=-j /2pifC
Don't forget to add 0V symbol to DC output (-)=GND as I did.... to indicate V' properly
Gnd symbol=0V and is not earth GND which is connected to Neutral at source.