The MD420 Emergency Power Supply System is designed to supply emergency power to the Mid-Continent Instrument 4200 and 4300 series attitude indicator when the aircraft main power buss has been de-energized. Additionally, the MD420 will supply emergency lighting power to two additional instruments such as an airspeed and altimeter. During normal aircraft operation, the MD420 will utilize the aircraft main power buss to recharge or maintain existing charge on the System.
Simultaneously provides one primary power output and three lighting power outputs
Pitot/Static ports or optional electrical input provides ability to work in automatic mode without pilot intervention Arms at beginning of flight Activates instantly upon power loss Recharges during flight Turns off after flight
Utilizes sealed lead-acid cells for reliability and cold weather performance
Lighting outputs can power LED or incandescent lighting at 5, 14 or 28 VDC
Remote, mini-annunciation switch (with automatic dimming) controls test and manual operations
Quality Mil-Spec connectors included
Field replaceable battery module(s)
Designed to operate Mid-Continent Instruments’ standby attitude indicator for one hour after primary power loss
Amp-hours of power at 18V: 1.0 Ah
Total system weight: 3.2 lbs.
Designed and built in Wichita, Kansas, USA
One year limited warranty
Power Input: 10–32 VDC; 0.25A nominal, 4.0A max (14V) 2.0A max (28V)
Power Output: 18 VDC nominal
Battery Capacity: 1.0 Ah (0.05C) at 25°C
Certification: FAA TSO-C4c and RTCA DO-160E
Weight: 3.2 lbs.
Mating Connector: 25-pin female D-Sub (MD25F20JVL0 or equivalent), 9-pin female D-Sub (MD9F20JVL0 or equivalent)
Annunciator Lighting: LED backlighting, automatic internal dimming
Battery Charging: Automatic recharging when main power is present
Compatibility: Provides 60 minutes minimum (when fully charged) of backup power to Mid-Continent’s Electric Attitude Indicator Model 4200 or 4300 and lighting power to two additional instruments (5, 14 or 28V)
Battery run time will vary depending on total power load for all other installations