Switching power supply apparatus

摘要

A switching power supply apparatus includes a voltage step-up converter that increases input voltage in response to turning on and off of a switching element, a transformer including a primary winding and a secondary winding and the primary winding of which is connected to the output of the voltage step-up converter, a microcontroller that controls the turning on and off of the switching element, an input voltage detection circuit that detects input voltage of the microcontroller, and an intermediate bus voltage detection circuit that detects intermediate bus voltage from the microcontroller. The input voltage detection circuit and the intermediate bus voltage detection circuit are circuits including elements having the same specifications. The microcontroller controls the turning on and off of the switching element based on a result of calculation from voltage values detected by the input voltage detection circuit and the intermediate bus voltage detection circuit.

主权项

1. A switching power supply apparatus comprising:
a voltage input portion; an front-stage converter configured to convert input voltage input into the voltage input portion into a first voltage in response to turning on and off of a first switching element; a subsequent-stage converter configured to convert an output voltage of the front-stage converter into a second voltage in response to turning on and off of a second switching element; an input voltage detection circuit configured to detect the input voltage of the front-stage converter; an intermediate bus voltage detection circuit configured to detect an intermediate bus voltage, which is the output voltage of the front-stage converter; and a control unit configured to and programmed to include:
a sampling portion configured to compare detection signals detected by the input voltage detection circuit and the intermediate bus voltage detection circuit with a reference voltage for sampling;a voltage calculating portion configured to calculate measured values of the input voltage and the intermediate bus voltage using the detection signals detected by the input voltage detection circuit and the intermediate bus voltage detection circuit with a calculation expression;a storage portion configured to store a coefficient of the calculation expression; anda communication portion configured to transmit the voltage measured values to an external apparatus and receive the coefficient from the external apparatus; wherein the input voltage detection circuit and the intermediate bus voltage detection circuit are circuits including elements having the same specifications; the sampling portion uses a same reference voltage to sample the detection signals detected by the input voltage detection circuit and the intermediate bus voltage detection circuit; and a same calculation expression is used to calculate the measured values of the input voltage and the intermediate bus voltage and a same coefficient is used in the calculation expression.