Hydrophobic aggregates for use in refractory castables and gunning mixtures and methods of their preparation. A high frequency ignition voltage is only applied to the lamp during a starting operation. In another embodiment, in a calibration circuit, an adaptive positive DC offset is added to the output of a delay buffer to advance the phase of the clock output, which also has a phase delay from the delay buffer. The invention is placed in a non-critical region of the optical spectrum and is independent of all other chassis equipment. When the fault signal is maintained until the setting duration of the timer is timed up, a time-out signal is released to stop the engine. Those devices are balanced in line capacity balance relative to one another.