Abstract: A light source including a spiral line pulse generator having an output coupled to one electrode of a high pressure discharge lamp and having an input for coupling to a source of lamp operating power for providing high voltage lamp starting pulses. The pulse generator includes, in addition to a spiral line circuit, a solid state electronic switch for discharging the spiral line pulse generator and a ballast capacitor connected in series with the solid state switch. The spiral line pulse generator preferably has a magnetic core associated therewith for increasing the spiral line inductance.

Abstract: Starting and operating apparatus for high intensity discharge lamps includes first and second pairs of terminals formed for connection to an AC source and a discharge lamp respectively, a series connect ballast means and inductor connected to one of said first pair and one of said second pair of terminals a bilateral switch shunted by a capacitor and in series with an AC impedance coupled to the inductor and to the other one of said first and second pair of terminals whereby relatively wide high voltage, high frequency pulse potentials for starting the discharge lamps are provided.

Abstract: A transmitter circuit adapted to transmit control signals to receivers which in turn activate fluorescent lamp fixtures. The transmitter comprises a frequency controllable oscillator and means coupled from the oscillator for providing alternating cycle control signals adapted to control the drive of the load. A divider circuit is used responsive to the oscillator frequency for providing a divided frequency signal of lower frequency of that of the oscillator. Feedback means including biphase means is responsive to the divided frequency signal and is coupled to the oscillator for controlling the oscillating frequency thereof. The oscillator output frequency is switchable at the divided frequency signal rate from a first frequency to a second frequency under control from the divider circuit.

Abstract: A frequency responsive power control system includes an improved isolator in series electrical connection with respect to a ballasted lamp load. The isolator has a high inductive impedance at low current for blocking ballast induced noise signals from interferring with proper operation of frequency responsive switching circuits in the system. In a particularly useful embodiment, the isolator is inductively matched to the capacitive characteristic of the ballasted lamp load so that the isolator-load circuit combination is resonant at a frequency sufficiently removed from any of the control system activation frequencies so as to block any noise signals induced by the ballasted load which might otherwise cause undesired activation of the switching circuits and flickering of the ballasted lamp loads. Under saturation current, with the switching circuit conducting, the isolator functions collectively with the load to provide an impedance which blocks control signals from reaching the load.