Abstract: Arc lamps, including low-pressure arc lamps, are coupled to drive circuitry operable to provide drive signals that reduce or eliminate excess current when the lamp arc is struck. The drive circuitry controls the rate at which a lamp can fire by actively controlling the rate the voltage pulse increases. Prior to enabling the drive pulse burst, the frequency is shifted only part of the way towards the normal operating frequency in a single step, then allowed to approach the normal operating frequency in a fashion that is selected based at least in part upon the specific type of lamp being used. Typically, the rate of change of the frequency is linear.

Abstract: Circuitry, which is compatible with incandescent light dimmers, is disposed within the screwbase of a compact fluorescent light, and sets driving frequencies for a mercury plasma, based, at least in part, on sensing the duty cycle of the incoming AC supply waveform. In this way, existing lighting infrastructure, including phase-cut dimmer circuits for incandescent light bulbs, may be preserved, and incandescent bulbs can be replaced with compact fluorescent lights equipped with circuitry in accordance with the present invention. In a further aspect, the circuitry synchronizes the bulb drive signals with the AC power line frequency.

Abstract: Circuitry, which is compatible with incandescent light dimmers, is disposed within the screwbase of a compact fluorescent light, and sets driving frequencies for a mercury plasma, based, at least in part, on sensing the duty cycle of the incoming AC supply waveform. In this way, existing lighting infrastructure, including phase-cut dimmer circuits for incandescent light bulbs, may be preserved, and incandescent bulbs can be replaced with compact fluorescent lights equipped with circuitry in accordance with the present invention. In a further aspect, the circuitry synchronizes the bulb drive signals with the AC power line frequency.

Abstract: A system for generating a reward when a shopping cart is returned to a holding pen. The entrance to the pen is defined by a pair of spaced apart pedestals containing a light source projecting on photo diodes. When the light on the diodes is interrupted by the upright strands of a cart, a set of pulses is generated and counted. The counts are fed to decision logic which control the reward generator. The reward generator is rendered operable only if the decision logic determines that a shopping cart has been pushed between the pedestals into the holding pen.