Accu charger with IC LM723C

The above is a circuit of 12 V accu/ battery charger . With input from the first transformer - voltage 220 initially V/110V/240V, lowered approximately 12 VAC, then voltage 12 Volts will be rectified by D1 and then filtered by C1 , then filtered and amplified again by IC LM723 and NPN transistor , output voltage is ready to use. Part list : T1 = Transformer , DC 12 V D1 = Diode bridge C1 = 470uF /50V C2 = 1000pF R1 = 4R7 R2 = 5K R3 = 3K9 R4 = 7K5 R5 = 8K2 VR = 2K - 5K trim TR1 = MJ2840 IC = LM723C