The silicon carbide bipolar junction transistor needs large transient currents supplied into and out of its base terminal for rapid switching. To realise this, it is normally desirable to have a base driver circuit supply rail at a high voltage. However, the device also needs a steady base current to hold it in the on-state. Supplying this current from a high-voltage source is inefficient. A circuit is presented that applies high transient base-emitter voltages, but with low driver circuit power consumption.