The utility model provides a coreless induction melting furnace and a monitoring circuit. The monitoring circuit includes a rectifier circuit, a signal processing circuit for converting a voltage signal into a switch control signal, a signal transmitting interface and a PLC control circuit. The rectifier circuit is electrically connected to a thyristor voltage output terminal, the rectifier circuit is electrically connected to the signal processing circuit, and the switching control signal output by the signal processing circuit is transmitted to the PLC control circuit through a signal transmission interface. The PLC control circuit is electrically connected to a switch circuit and is configured to receive a switch control signal. The switch circuit is provided in a power supply circuit of the induction melting furnace and is configured to form a loop when the power supply circuit is closed. The coreless induction melting furnace includes a plurality of thyristors and a plurality of the above-mentioned monitoring circuits corresponding to the thyristors on a one-to-one basis. The application can directly display the operation of the thyristor, quickly and effectively detect the failure of the thyristor, and stop the machine in time to protect the personal safety of the equipment and the operator.
http://www.songdaokeji.com/plus/list.php?tid=22