[ X_C = \fracV_in,RMS - V_zI_out = \frac230 - 120.05 \approx 4360 \Omega ]
[ I_load \approx \fracV_in,RMS - V_zX_C ]
[ C_filter = \fracI_out2f V_ripple = \frac0.05100 \times 1 \approx 500 \mu F ] (assuming 1V ripple). asaan converter
[ P_z = V_z \times I_out = 12 \times 0.05 = 0.6W ] → use 1W Zener. 4. Efficiency Analysis Efficiency ( \eta = \fracP_outP_in ). Input power measured via wattmeter simulation.
: If dropper capacitor fails shorted, full mains voltage appears at output, destroying load and creating fire risk. [ X_C = \fracV_in,RMS - V_zI_out = \frac230 - 120
This paper investigates the engineering trade-offs: low cost vs. safety, efficiency vs. ripple, and compactness vs. heat dissipation. The circuit relies on the capacitive reactance ( X_C ) to limit current without dissipating significant heat (unlike a resistor). For a sinusoidal AC mains voltage ( V_in(t) = V_p \sin(\omega t) ):
: At plug-in, if AC peak coincides with capacitor discharge, ( I_peak ) can exceed 50A, damaging rectifier diodes unless a series resistor (e.g., 10Ω) is added. Efficiency Analysis Efficiency ( \eta = \fracP_outP_in )
Below is a structured, in-depth research paper suitable for an engineering or applied physics context. Abstract Transformerless AC-DC converters, often marketed as low-cost power supplies for LED lighting, small fans, and battery chargers, provide a simple and inexpensive solution for low-current applications (<100 mA). This paper analyzes the operating principles, mathematical modeling, component stress, efficiency, thermal behavior, and critical safety hazards of such circuits. While their "easy" (Asaan) design reduces material cost and weight, inherent non-isolation from mains poses electric shock risks, and poor power factor leads to grid harmonics. Experimental simulations are presented for a 12V, 50mA capacitive dropper, followed by recommendations for safe implementation and regulatory compliance.