Current controlling system of power source circuit

Abstract

Abstract PURPOSE:To decrease the output voltage and current of a smoothing circuit in an overcurrent state and to return a comparison control circuit to a stationary state at releasing time from the overcurrent state, by forming a closed loop by using a current detecting circuit, switching element, smoothing circuit, etc. CONSTITUTION:Current detecting circuit 4 consists of current detecting resistance 12, transistor TR13 turning on when a current control function is in operation, constant voltage generating circuit 14, etc., and circuit 4, switching element 2, smoothing circuit 3, etc., form a closed loop. Once an overcurrent flows through element 2, the on-period of element 2 is shortened to decrease both the output voltage and current of smoothing circuit 3. Once release from the overcurrent state is obtained, the current flowing through resistance 12 gets stationary and the overcurrent control signal supplied via TR13 is held at about 0V, placing comparison control circuit 6 and switching element driving circuit 7 in stationary states.

Inventors

• 👤 Naoto Kagawa
• 👤 Kunio Iwamoto

Bibliographic Details