FEBC Operation
Page 2
1.0 SCOPE
This document describes the operation, calibration, and specifications associated with the Fluorescent Electronic
Ballast Controller (FEBC).
2.0 GENERAL DESCRIPTION
The FEBC will provide the function of interface between DMX512, or CMX and solid state electronic ballasts or other
devices that use a DC control voltage up to 12 Vdc.
Figure 1 shows the block diagram of the FEBC circuit. Note that the contactors are not shown in this diagram.
Containing 4 channels, the FEBC provides 4 analog output signals which may be adjusted to operate at full scale
between 5Vdc and 12Vdc. There are also four contactor controllers which provide the drive signal associated with air
gap relay requirements for dimmable fluorcscerlt ballasts.
Dimmer addressing is achieved by selecting the starting dimmer address on the BCD switche's located at the edge
of the card. 4 consecutive dimmer values are sampled from the optoisolated DMX512, or CMX serial signal and
processed by the FEBC's microcontroller.
Analog outputs represent a scaled voltage of the 4 dimmer inputs. A potentiometer is adiusted for each channel to
establish the full scale output voltage. The maximum voltage swilg is. adjustable for an output scale of approx. 0V to
12 Vdc.
The 8 position DIP switch provides for the following options:
Linear or Square Law output
Normal/Non-dim select
Calibration (Full scale output)
Contactor Disable
There are 4 solid state relays (zero-crossing) provided to supply drive current to off-board air gap contactors. These
opto-coupled relays require an external power source (typically 115 / 230 Vac) to drive the contactors. It may be
possible to drive 1 or 2 A.C. loads directly frorn the FEBC controller board and eliminate the contactors for economy
sake.
Input power is jumper selectable between 115 Vac and 230 Vac @ 50/60 Hz. A primary fuse (1A Slo-blo) is provided
on-board.
Summary of Contents for FEBC
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