Honeywell SG-60 installation and operation guide SGC-60 Master Controller

Airport Systems

3.3SGC-60 Master Controller

3.3.1Power Supply

The Master Controller input power is connected to PB1, which then feeds transformer T1 (under the switch panel). The Master Controller can accept a number of input voltages, depending on the primary tap connections to T1, and will operate at 50 or 60 Hz. The T1 transformer output provides 12VAC to the Master Controller circuit board PCB1 (T1-17 and T1-18 connecting to PCB1 TB1-1 and TB1-2). The input voltage passes through fuse F1, is rectified by DB1, and filtered by C16.

This unregulated voltage (about 16VDC) is available for external use TB8. The 16VDC is also fed into the switch mode power supply (including voltage regulator VR1), which provides regulated +5VDC to the rest of the board.

The 16VDC is also used to provide power for the power-down circuit. The power-down circuit can briefly shut down the regulated +5VDC supply powering the rest of the board logic, providing a power-on reset for the rest of the board logic.

The power-down circuit will be activated automatically if (1) the microcontroller stops functioning normally, or (2) the microcontroller detects a severe communications failure. To prevent nuisance alarm chatter, the microcontroller will only deliberately activate the power-down circuit if at least 24 hours have elapsed since the last power on.

The power-down circuit is intended to allow automatic recovery from rare cases when transients lock up the communications transceiver, but it can also be used as a manual board reset. . You may test this function by holding down the RESET toggle switch on the switch panel for about 1 second.

If input power is lost, or fuse F1 is blown the Power Fail Relay (K4, terminals TB3-C3, -NO3, -NC3) will de-energize.

3.3.2Flash Requests and Flashhead Status

The Master Controller transmits a flash request command to the Flashheads every 1.5 seconds (or every 1.0 seconds in Catenary mode, selected with SW2-1). The flash request also contains the requested operating mode. The flash request applies to all Flashheads, but is addressed to a specific Flashhead.

All Flashheads receive the flash request. All Flashheads flash in response to the request, and update their operating mode, but only the addressed Flashhead may reply to the Master Controller.

Whenever a the Flashhead replies OK, the Master Controller marks it as good, and sets the corresponding Flashhead Status LED to green.

If the Flashhead does not reply OK, the Master Controller marks it as bad, and sets the corresponding Flashhead Status LED to red.

SG-60 High Intensity Strobe System 3-8 Manual EPM-00000019 Rev A