A network LED dimmer recently introduced by Opto 22 provides low voltage, flicker-free control of 12/24V DC LED lamps, bulbs, and strips using DMX, Modbus, or Optomux serial communications.
The new dimmer uses pulse width modulation technology (PWM) to control brightness from 0-100 percent for 9-30 to control VDC constant voltage LED lighting assemblies such as lamps, bulbs, strips, ropes, and bars. It can also be used for other resistive-type loads.
Pulse width modulation provides linear dimming with minimal color shift and flicker-free performance. The dimmer is unique because it controls the amount of power sent to the LEDs, rapidly changing the state from on to off. Use of these high switching frequencies makes dimming efficient and effective for LEDs.
Potential uses are vehicle and vessel applications where energy efficiency and the long life of low-voltage LED lighting would be an advantage. Because it is packaged in a compact, rugged enclosure, the design might be interesting for machine builders who want to implement LED lighting as part of their product.
The unit can be used alone or in combination with other dimmers for any application that requires variable light from LEDs. Lighting designers, facility engineers, and architects can use the dimmer in applications such as stage or accent lighting, LED color mixing, path marking, backlighting, and facade or wall lighting. When connected to an RS-485 serial network, multiple dimmers can be integrated into a lighting, automation, or building control system that supports either the DMX512-A, Modbus/ASCII, or Optomux network protocols.
The network dimmer uses an RS-485 serial network, and serial link connections are made by bare-wire spring connectors. Duplicated positions on the connector simplify daisy chaining, and up to 128 dimmers can be on the same serial link. Two blocks of DIP switches inside the case let the user set parameters such as the communications protocol, address, serial line termination, baud rate (Modbus and Optomux only), and parity (Modbus only).
A built-in test pushbutton is used for ramping LED intensity up and down, connectors for wiring a pushbutton for manual operation, and indicator lights to show serial communication and ramping operation.