AC Powered White LEDs

One of the major problems that is to be solved in an electronic circuit design is the production of low voltage DC power supply from Mains to power the circuit. The conventional method is the use of a step-down transformer to reduce the 230 V AC to a desired level of low voltage AC. The most simple, space saving and low cost method is the use of a Voltage Dropping Capacitor in series with the phase line.

It can give ample light even for reading purpose. Capacitor C-1 along with diodes D1 through D4 forms the AC step down circuit. C-1 reduces high voltage AC from mains to a low voltage AC which is rectified by the diodes D1-D4.
A Smoothing Capacitor C-2 is used to generate ripple free DC. Smoothing capacitor is also called Filter capacitor and its function is to convert half wave / full wave output of the rectifier into smooth DC.
Resistor R1 is very important to remove the stored voltage from C-1 when power is switched off. This prevents lethal shock.
Warning- Do not touch any part of circuit when power is plugged in or it is unplugged recently (wait for 2 minutes). It can give lethal shock. Attempt this project only if you have experience in working with AC mains voltage and are comfortable with it.

List of parts required.
30 pieces or more of White LED's of 5mm size.
1- Non Polarized PPF Capacitor .22 uF or 224J rated 400 volts AC
1 Resistance of 470k -1/4 watt
1 Resistance of 100 Ohms – 1/4 watt
4 Diodes IN-4007
1 electrolytic capacitor 10 uF 160 volts
4 inches width and 8 inch long cardboard.
wire, wall plug, solder etc.