I found some articles talking about transformerless power supplies, and I have uploaded the schematic of such a circuit. Does anybody have an idea about the pros and cons of such a power supply? Also how to calculate the value of this capacitor "C1" ?
Polypropylene power supplies are a type of capacitive power supplies that supplies a limted current output. The value of the polypropylene capacitor determines the amount of current according to this equation:
X = 1 / (2 π f C)
I = V / X
X : capacitor reactance
π : Constant (pi) = 3.14
f : frequency of the main supply (50-60)
C : Capacitance value
I : output current (A)
V : main voltage (110 or 220)
- constant current power supply is better in some applications like LED Lighting
- wide output voltage range (typically any rated voltage device is able to connect -unless it stands the applied current- )
- More efficient series connections are possible in some applications like LED lighting
- Non-isolated power supply which means rush current can easily destroy your load
- low output current values (Max ~ 350 mA) due to low available capacitance values. or huge number of parallel connected capacitors (10) to output a current of about 1 Amp.