Controller for power converter

A controller for a power converter having at least a first switch and a second switch, each switch being a transistor with a collector terminal, an emitter terminal, and a base terminal, the controller connectable to the base terminals of the first and second switches to provide a base current to the base terminals of the first and second switches, and connectable to the emitter terminals of the first and second switches to provide a short-circuit between the base and emitter terminals of the first and second switches, the emitter terminals of the first and second switches being joined together to provide the short-circuit between the base and emitter terminals of the first and second switches, the controller comprising a clamping switch connected between the emitter and base terminals of the first and second switches and closeable to provide the short-circuit between the base and emitter terminals of the first and second switches, and a timing circuit for controlling the provision of the base current and the short-circuit in a sequence, the controller further comprising:

• a first terminal for connection to the base terminal of the first switch;
• a second terminal for connection to the base terminal of the second switch;
• a third terminal for connection to the emitter terminals of the first and second switches;
• the controller adapted to provide positive base current pulses to the first terminal, the positive base current pulses being returned from the third terminal;
• the controller adapted to provide negative base current pulses to the second terminal, the negative base current pulses being returned from the third terminal;
• the controller adapted to provide a short-circuit between the first and third terminals;
• the controller adapted to provide a short-circuit between the second and third terminals;
• and
• the timing circuit controlling the sequence of the provision of the positive and negative current pulses and the short-circuits.