Hi Babar,

At 230V your resistor heat with P = U²/R = 230²/10000 = 5.3W.
Since the maximum power dissipation was defined on free air at 20°C,
you should minimal use an 8W or 10W resistor.

But the better way was using a capacitor,
since it generate no heat (blind resistor).
E.g. with 470nF you get a current of
230V * 2 * Pi * 50Hz * 470nF = 30mA (20mA at 115V, 60Hz).
The capacitor must minimal made for 400V better 630V or 1000V.
Also a 100 Ohm resistor in series was good to limit the
peak current during power on.

Also you can never use the 7805, since 230V in series with 10kOhm
looks like a current source.
And decreasing the current consumption by 10mA causes
a voltage increasing of 10kOhm * 10mA = 100V, which
definetively kills your 7805 (and the 2051 after this).

You need a load, which limit the voltage by consuming all unused current,
means a 5V Zener diode e.g. for 500mW (30mA * 5V = 150mW).

20mA are enough for the 2051, but I know not your
additional circuit.
You must calculate the capacitor with the above given formula,
if you need more current.


Peter