Voltage Regulators LM7812 and LM317

You could use LM7824 or LM7815 or LM7812 for 24V, 15V and 12V respectively. You could use LM7924 or LM7915 or LM7912 for -24V, -15V and -12V respectively.

The Filter capacitor C1 4700uF has an impedance of

**Xc = 1 / (2 * 3.14 * f * C)**which comes to 0.6 ohms at 50 Hz.

Power Electronic Circuits

The impedance of the load at 2A for 24V is

**R = V / I**that is 12 Ohms which is more than 20 times the impedance of the capacitor at 50 Hz. That means less than 1 / 20 of ripple current will flow thru the load. The Regulator also reduces the ripple a little.