

The converter is used to convert voltage signal levels Synchro/Resolver to ARINC digital value corresponding to the angle measured. The digital value is broadcasted on the ARINC bus. The device has three channels (3× – XYZ, 3× – reference phase) and for each channel it is possible to set the type of input signal synchro/resolver. A logical signal informing about the validity is attached to each channel.
Technical parameters
Analog Input Type: Synchro (XYZ) or Resolver (SIN/COS)
Number of channels: 3 fully independent
Analog Input:
- 3x Synchro/Resolver
- 3x 26V/36V 400 Hz
- 3x reference signal, 26V/36V 400 Hz (ARINC 407 or Russian)
Digital Input:
- 3x flag input – opto isolated
Communication interface:
- ARINC 429
- RS 232 for service only
General Parameters
Input Impedance: 20 kOhm, f=400 Hz
Conversion Accuracy: ±0,3 °
Power Supply: 14…32 V DC
Power Consumption: 5 W
Operating temperature: -55 – 70 °C
Storage temperature: -55 – 85 °C
Humidity: max. 95 %
Connectors: MIL-37, CAN 9
Dimensions: 206 x 70 x 100 mm
Weight: 1500 g
Supported ARINC labels
320 – Magnetic Heading
321 – Drift Angle
324 – Pitch Angle
325 – Roll Angle
235 – Baro Correction inHg
162 – ADF Bearing
274 – Heading Status
222 – Bearing
The converter is also capable of performing self-diagnostics; it monitors supply voltage level and input signal or its validity. If an error is detected the converter halts and signalizes error.
LUN 1794.3 is successfully installed on L-410, L-410 UVP, Jak-40, Tu-154, An-26 and L-39 aircraft and MI-24, MI-17 helicopters.
There are many old synchro or resolver systems (LUN 1205 Electrical gyro horizont, russian GMK gyro among others) which can serve as sources of analogue signals for LUN 1794 output ARINC interface is directly connected to safety aircraft systems from Bendix/King – Honeywell (EGPWS, TCAS System).
LUN 1794 is also successfully instaled on russian Mi-171, Mi-17V-5 and Mi-24 helicopters. It works as the signal source for heading GMK and for roll and pitch AGB-96D, AGB-3K, ARK-15 or ARK-UD.
Variants specification
LUN 1794 is available in multiple variants based on available input and output types and use cases. Click on one of the variants for more information about them.
LUN 1794: Synchro/Resolver to ARINC 429
Inputs
- 3× Synchro/Resolver (ARINC 407/Russian)
Outputs
- ARINC 429 LS/HS
Basic Synchro/Resolver to ARINC 429 variant.
LUN 1794.1: Synchro/Resolver and Synchro DC to ARINC 429
Inputs
- 2× Synchro/Resolver (ARINC 407/Russian)
- 1× Synchro DC (DESYN)
Outputs
- ARINC 429 LS/HS
Synchro/Resolver and Synchro DC to ARINC429 variant.
LUN 1794.2: Synchro/Resolver and 1 phase gyro to ARINC 429
Inputs
- 1× Synchro/Resolver (ARINC 407/Russian)
- 2× 1 phase gyro (ECFR 251)
Outputs
- ARINC 429 LS/HS
Synchro/Resolver and 1 phase gyro (ECFR 251) to ARINC429 variant.
LUN 1794.3: Russian synchro to ARINC429 LS/HS OBS selector
Inputs
- 1× Russian Synchro
- Vertical deviation
- Lateral deviation
- TO/FROM signals
Outputs
- ARINC 429 LS/HS OBS selector (Resolver)
- Vertical deviation
- Lateral deviation
- TO/FROM signals
Converts analog signals of vertical deviation, lateral deviation and signals of vertical and lateral deviation validity from main output of GNS430 unit to format suitable for Russian navigation indicator NPP or similar. Converts OBS(ZK) selection from Russian NPP to GNS OBS Resolver input.
LUN 1794.4: Synchro/Resolver and Synchro DC to ARINC 429
Inputs
- 1× Synchro/Resolver (ARINC 407/Russian)
- 2× Synchro DC (DESYN)
Outputs
- ARINC 429 LS/HS
- 1x GPO Relay
Synchro/Resolver and Synchro DC to ARINC 429 variant.
LUN 1794.5: Synchro/Resolver to ARINC 429 and Synchro/Resolver (ARINC 407) to connect EHSI
Inputs
- 1× Synchro/Resolver (ARINC 407/Russian)
Outputs
- ARINC 429 LS/HS
- 1× Synchro/Resolver output (ARINC 407)
Synchro/Resolver to ARINC 429 and Synchro/Resolver (ARINC 407) to connect EHSI variant.
LUN 1794.6: Synchro/Resolver and DC Baro Correction inHg to ARINC 429
Inputs
- 2× Synchro/Resolver (ARINC 407/Russian)
- 1× DC
Outputs
- ARINC 429 LS/HS
Synchro/Resolver and DC Baro Correction inHg to ARINC 429 variant
LUN 1794.7: Synchro/Resolver to ARINC 429 to Runway Markers (GPO Relays)
Inputs
- 3× Synchro/Resolver (ARINC 407/Russian)
- ARINC 429
Outputs
- ARINC 429 LS/HS
- 3x GPO Relay
Synchro/Resolver to ARINC 429 and ARINC 429 to Runway Markers (GPO Relays)
LUN 1794.8: Deviation and TO/FROM signals to ARINC 429
Inputs
- 2× Synchro/Resolver (ARINC 407/Russian)
- Vertical deviation
- Lateral deviation
- TO/FROM signals
Outputs
- ARINC 429 LS/HS
Converts analog signals of vertical deviation, lateral deviation and TO/FROM signals to ARINC 429.
Supported airplanes and helicopters
Aircrafts |
L-410, L-410 UVP, L-39, An-24, An-26, An-28, Jak-40, Tu-154, Dassault Falcon 50, Mig 21, Mig 29, McDonnell Douglas MD-11 |
Helicopters |
MI-24, MI-171, MI-171S, MI-171Sh, MI-172, MI-17V-5, MI-8, Bell Helicopters |
Block diagram
