Method and apparatus for protecting transistors

An apparatus for protecting transistors arranged in at least one path, the apparatus comprising:

• at least two transistors connected in series and arranged in the at least one path, an input voltage being applied to the at least two transistors, wherein the at least two transistors are arranged for alternate switching between a conductive state and a blocking state in order to generate an output voltage at a center of the at least one path,
• at least one measuring device arranged for the at least one path for protection against a simultaneous conductive state of the at least two transistors, said at least one measuring device being designed for checking the blocking state of a second transistor of the at least two transistors before switching a first transistor of the at least two transistors into the conductive state,
• a control for the at least two transistors, the control being connected with the at least one measuring device, and
• at least one flyback diode coupled to at least one of said at least two transistors wherein said measuring device is configured to check a status of at least one flyback diode of said at least two transistors before another of said at least two transistors is switched into a conductive state;
• a voltage divider, wherein the voltage divider comprises at least two resistors, and wherein said measuring device is configured to read a change in potential to determine whether to switch at least one transistor from a blocking state to a conductive state;
• wherein the at least one measuring device is designed for generating a signal for the switching of a transistor of the at least two transistors.

A method for protecting transistors arranged in at least one path, the method comprising steps of:

• providing at least two transistors connected in series and arranged in the at least one path;
• applying an input voltage to the at least two transistors;
• checking a voltage across at least one flyback diode coupled to at least one of said at least two transistors;
• determining a blocking state of at least one transistor based upon said voltage across said at least one flyback diode;
• switching at least one transistor of the at least two transistors into a conductive state based upon a blocking state of at least another transistor of said at least two transistors;
• alternately switching the at least two transistors between a conductive state and a blocking state in order to generate an output voltage at a center of the at least one path, for protection against a simultaneous conductive state of the at least two transistors;
• releasing the switching by way of a signal generated during the check, said signal comprising a first state and a second state;
• defining a potential at a center of a path via a voltage divider having at least two resistors coupled in parallel with at least one transistor;
• and
• comparing said defined potential with a reference voltage to determine a change in potential to determine whether to initiate switching of at least one transistor;
• wherein the switching is released in the first state and the first state comprises a release state;
• and
• wherein the switching is carried out by a control when the generated signal has the release state at a defined switching time.