Zilog, Inc.

Ixys Intl Limited

Ixys Ch Gmbh

Yefim Gluzman

Quyen Tran

Kamlapati Khalsa

David D Eaton

A multi-lamp fluorescent light fixture includes a plurality of replaceable fluorescent lamp starter units. Each starter unit has a built-in microcontroller, an RF (Radio-Frequency) receiver, and communicates wirelessly with a master unit. The plurality of starter units can be wirelessly controlled to dim the multi-lamp fixture. Each starter unit receives a DIM command. Each starter unit identified as a dimmer starter unit responds to the DIM command by turning off coupled fluorescent lamps. Starter units not identified as dimmer starter units respond by leaving coupled lamps turned on, or alternatively, turning off and quickly restarting coupled lamps. Systems of existing light fixtures are retrofitted with such wireless starter units, and thereby made controllable by a master unit so that the master unit can dim the lights if room occupancy is not detected or if sufficient ambient light is available.

Dimming a multi-lamp fluorescent light fixture by turning off an individual lamp using a wireless fluorescent lamp starter

A multi-lamp fluorescent light fixture includes a plurality of replaceable fluorescent lamp starter units. Each starter unit has a built-in microcontroller, an RF (Radio-Frequency) receiver, and communicates wirelessly with a master unit. Each starter unit can be wirelessly controlled to turn off coupled fluorescent lamps. Each starter unit receives a turn off command, monitors the AC voltage supplied to coupled lamps, and initiates turn off when the AC voltage reaches a threshold voltage stored in a memory of the microcontroller. In one novel aspect, each threshold voltage is selected such that turn off of lamps coupled to each starter is initiated within one millisecond. Systems of existing light fixtures are retrofitted with such wireless starter units, and thereby made controllable by a master unit so that the master unit can turn off the lights if room occupancy is not detected or if sufficient ambient light is available.

Turning off multiple fluorescent lamps simultaneously using RF-enabled lamp starter units

A fluorescent lamp starter unit determines whether the lighting fixture into which it has been plugged is in a first or second state. The lamp is on in the first state and off in the second state. If the fixture is in the first state then the starter unit uses a first method to detect ballast type, whereas if the fixture is in the second state then the starter unit uses a second method to detect ballast type. In one example, the first method involves turning on the power switch of the starter unit at a time after a zero-crossing and then using the periodicity of a transient switch current signal to determine ballast type, whereas the second method involves turning on the power switch at the time of the zero-crossing and then using peak amplitude information of the transient switch current to determine ballast type.

Fluorescent lamp starter unit having a hot socket insert capability

A starter unit (for example, an RF-enabled and replaceable starter unit) has an ability both to turn on and to turn off a fluorescent lamp. The starter unit detects whether a ballast in the circuit with the fluorescent lamp is of a first type (for example, an L-type ballast) or is of a second type (for example, a C-type ballast). If the determination is that the ballast is of the first type, then the starter unit turns off the lamp in a first way (for example, using C-type timing and then using L-type timing alternatingly). If the determination is that the ballast is of the second type, then the starter unit turns off the lamp in a second way (for example, using only C-type timing). The same starter unit design is usable both in single-lamp fixtures and in multi-lamp fixtures where a mix of ballast types may be used.

Alternating turn off timing of a fluorescent lamp starter unit

In a circuit that turns off a fluorescent lamp, clamping circuitry is provided to dissipate energy stored in a ballast when the lamp is being turned off. In a normal state in which the lamp is on, or in a normal state in which the lamp is off, clamping is not performed as long the VDS of a power switch is below a voltage A. In a lamp turn off operation, the switch is turned on for a time period to extinguish the lamp, and is then made to operate as a clamp (operate in its linear region) for a second period of time to dissipate energy that was stored in the ballast. Clamping in the linear region continues for VDS voltages down to B as ballast energy is dissipated, where B is smaller than A. By clamping down to the lower voltage B, re-ignition of the lamp is prevented.

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San Francisco, CA, United States of America

Yefim Gluzman