An over-voltage protection system for an accelerator can include: a plurality of DC power supplies configured to provide a plurality of voltage levels up to a desired voltage level; and an acceleration tube electrically connected to the plurality of DC power supplies and configured to accelerate a charged particle. The acceleration tube can include a plurality of stages. Each stage can include a plurality of electrodes and a plurality of varistors configured to discharge energy in response to an overvoltage event. One electrode of the plurality of electrodes can be electrically coupled to a voltage level of the plurality of voltage levels. The plurality of electrodes and the plurality of varistors can be electrically coupled to each other and arranged in an alternating fashion.

The invention relates to a control circuit for protecting an electrostatic spray-coating apparatus, which has a high-voltage supply, against spark discharge. The control circuit has a disconnection device for automatically disconnecting the high-voltage supply, and has a device for detecting abnormal operation of the high-voltage supply. The device for detecting abnormal operation of the high-voltage supply is designed to monitor at least one parameter which is characteristic of the operation of the high-voltage supply, and to output a corresponding disconnection signal to the disconnection device when the at least one parameter which is characteristic of the operation of the high-voltage supply exceeds or falls below a predefined or predefinable limit value.

The invention relates to a control circuit for protecting an electrostatic spray-coating apparatus, which has a high-voltage supply, against spark discharge. The control circuit has a disconnection device for automatically disconnecting the high-voltage supply, and has a device for detecting abnormal operation of the high-voltage supply. The device for detecting abnormal operation of the high-voltage supply is designed to monitor at least one parameter which is characteristic of the operation of the high-voltage supply, and to output a corresponding disconnection signal to the disconnection device when the at least one parameter which is characteristic of the operation of the high-voltage supply exceeds or falls below a predefined or predefinable limit value.

In accordance with an embodiment, a connection circuit powered by a power supply circuit includes a connector configured to connect with an external device, a chip set configured to connect with the connector via one or more data lines and control serial communication with the external device via the data lines, and a switch circuit arranged between the connector and the chip set and configured to disconnect a connection between the connector and the chip set via the data lines when power is not supplied from the power supply circuit.

A protection circuit of a semiconductor device includes a high electron mobility transistor and a protection element. Between the drain and the gate of the high electron mobility transistor, the protection element includes: a thyristor; and a first resistor connected in series to the thyristor. Between the source and the gate of the high electron mobility transistor, the protection element includes: a second resistor and an interrupter that is connected in series to the second resistor. The interrupter interrupts a flow of a current between the drain and the gate when the thyristor is turned off, and the interrupter permits the current to flow between the drain and the gate when the thyristor is turned on.

An over-voltage protection system for an accelerator can include: a plurality of DC power supplies configured to provide a plurality of voltage levels up to a desired voltage level; and an acceleration tube electrically connected to the plurality of DC power supplies and configured to accelerate a charged particle. The acceleration tube can include a plurality of stages. Each stage can include a plurality of electrodes and a plurality of varistors configured to discharge energy in response to an overvoltage event. One electrode of the plurality of electrodes can be electrically coupled to a voltage level of the plurality of voltage levels. The plurality of electrodes and the plurality of varistors can be electrically coupled to each other and arranged in an alternating fashion.