Abstract: A starting circuit which is connected in parallel with the lamp. No ballast is required for the starting circuit. The starting circuit uses a pulse transformer, the primary of which is connected into an RC network, the secondary of which is connected in series with a capacitor which prevents current flow at the low frequency open circuit voltage. The circuit being in parallel with the lamp enables the use of low power components such as the pulse transformer, since the lamp operating current does not traverse the circuit as would be the case with a series starting circuit or ballast transformer.

Abstract: A control for an outdoor lighting fixture which adds an extra off-on cycle to that imposed by a photoelectric cell control. At a predetermined time during the on period of the lighting fixture, the lamp of the fixture is shut off. This shut-off time had previously been determined as one during which traffic in the area is at a minimum. A set time after the shut off, the lamp is lit once again, this time being selected as a time when traffic is re-appearing. When the ambient light reaches the shut-off level of the photoelectric cell, the lamp is shut off for the day. In this way, the lamp is turned off for a timed period for the purpose of reducing the energy required by the lamp for the dark hours of the night.

Abstract: A starting circuit for a high intensity discharge lamp. To provide the high voltage necessary for starting the lamp, the circuit uses a tapped transformer feeding a resistance-capacitance charging network coupled across the lamp. A voltage sensitive symmetrical switch is located in the network between the transformer tap and the RC junction to trigger the circuit when the open circuit voltage of the ballast is at its peak. A diode within the network is in series with resistance to allow current to flow during one half cycle of the cycle allowing the use of an inexpensive resistor in the RC network. A bleed resistor is placed in shunt of the capacitor to stabilize the triggering time of the network.