Honeywell MKXXII Electrical Interface Introduction, Signal Interfaces, Chassis Ground, DC Ground

Honeywell

MK XXII EGPWS Installation Manual

E 4 ELECTRICAL INTERFACE

E 4.1 INTRODUCTION

The MK XXII EGPWS provides electrical interfaces for aircraft systems and to support maintenance functions. The interfaces are made via the front panel aircraft interface connectors, front panel maintenance/test port and front panel LED’s. A TNC coaxial connector is located on the front panel for internal GPS receivers in the 965-1590-0XX MK XXII EGPWC. The following sections describe the types of electrical interfaces provided in the EGPWC. See Section E 5 for the specific interface configuration capabilities of the MK XXII EGPWS.

E 4.2 SIGNAL INTERFACES

This section identifies and describes the number and characteristics of each interface type provided in the front aircraft interface connectors. The aircraft interface connectors are defined as P1 (78 pins) and P2 (50 pins). Section E 6 identifies the connector pin assignments. The signal mnemonic for each signal in Section E 6 is included in the following sections. All synchro inputs are brought in as three or five wire devices. No two wire absolute AC signals are available. All analog inputs provide broken wire detection on all input signal legs. Unless otherwise stated, the “Maximum reverse fault current” is defined as the current resulting from an internal component failure, with the input signal at zero volts.

E 4.2.1 GROUNDS

CHASSIS GROUND

Used for redundant metal connection. This pin is internally connected to DC Ground (see section 0).

Pin Assignment (Signal Mnemonic): J1-42, J1-53 (GND)

DC GROUND

For discrete inputs and lamp driver outputs. These pins are also internally connected to Chassis Ground (see section 0).

Pin Assignment (Signal Mnemonic):
(same as +28 VDC Return)	J1-41, J1-61	(PWR_L)
NOTE: All analog signals are differential input.

E 4.2.2	PRIMARY POWER INPUT
Nominal Input		28 VDC
Normal Voltage Range		22.0 to 30.3 VDC
Normal Surge Voltage Range		15 – 40VDC (30 msec)
Abnormal Voltage Range		20.5 to 32.2 VDC
Abnormal Surge Voltage Range		37.8 VDC (1sec); 46.3 VDC (100 msec)
Normal Frequency Range		not applicable
Frequency Transients		not applicable
Power Requirements		9 Watts - No Warnings
		+7 Watts with warning voice over 8 Ω speaker
		+3 Watts with Internal GPS (includes antenna power)1
		+49 Watts (typical) with heater blanket on2
Recommended Power Control Device		3 Amp delayed action circuit breaker.
Pin Assignment (Signal Mnemonic):			(PWR_H3)
	+28 VDC Input	J1-40, J1-60
	+28 VDC Return	J1-41, J1-61	(PWR_L3)

1Based on the Honeywell GPS Pxpress card specification and applies to 965-1590-0XX only. 2The heater blanket turns on at temperatures ≤ -23°C and turns off at temperatures ≥ -20°C.

CAGE CODE: 97896 SCALE: NONE SIZE: A DWG NO: 060-4314-225 REV: C SHEET 167