Panasonic Intellectual Property Management Co., Ltd.

Tatsuya Sakurai

Takashi Saji

Keita Kawabe

Yoshihiro Mori

Koji Suzuki

Kazuhiro Murata

Yoshihisa Minami

Tetsuyuki Fukushima

Naohiko Morota

A switching power supply device of the present disclosure includes a device connection state detection circuit that detects a connection state in a load device connection terminal, in a power supply system having the load device connection terminal. The device connection state detection circuit includes a transformer, a switching element, a pulse generator, and a waveform detection circuit. The waveform detection circuit detects a voltage or a current generated at a connecting point between a primary winding wire of the transformer and the switching element in response to operation of a pulse signal. The waveform detection circuit compares the voltage or the current with a predetermined reference value, and outputs an output signal in response to a comparison result to an OFF terminal.

Switching power supply device

A switching power supply apparatus of the present disclosure is a device connection state detection circuit that detects a connection state in a load device connection terminal in a power supply system having the load device connection terminal. The device connection state detection circuit includes a transformer, a switching element, a pulse generator, and a waveform detection circuit. The waveform detection circuit detects a voltage or a current generated in a primary winding wire or a secondary winding wire of the transformer in accordance with operation of a pulse signal, compares the detected voltage or current with a preset reference value, and outputs an output signal in accordance with a comparison result, to an OFF terminal.

Switching power supply apparatus

A converter includes: a bridge diode; an X capacitor provided upstream of the bridge diode; a smoothing capacitor provided downstream of the bridge diode; an AC shutoff detection circuit which outputs an AC shutoff detection signal when input AC voltage is shut off; and a discharging circuit which is connected to a connection point at which the cathode of the bridge diode and the smoothing capacitor are connected, and allows residual charges in the smoothing capacitor and the X capacitor to be discharged when the AC shutoff detection signal is output, and the discharging circuit includes a JFET which has a drain terminal connected to the above connection point and lowers discharge voltage; and a first discharging switch element connected to the source terminal of the JFET.

Converter and semiconductor device

Growing community of inventors

Osaka, Japan

Tatsuya Sakurai