Today I searches the circuit in old book. Meet power supply circuit. very plentiful may advantage with friends. Then bring see this circuit basically the base of DC voltage Regulator follow the circuit gives voltage , get +13V and -13V by it uses Zener Diode . Perform maintain one’s position voltage. Be stable and use the principle of divide Voltage. With electronic resister makes the wage has pushed the electricity that is equal both of the positive and negative. The detail is other, request a friend sees in the circuit next.