Application Note 7511

.

FIGURE 13A. MOTOR CURRENT AND VOLTAGE ARE SHOWN HERE, FOR LIGHT LOADS

TRACE

VERTICAL

HORIZONTAL

 

 

 

A

1A/DIV

1mSEC/DIV

 

 

 

B

50V/DIV

1mSEC/DIV

 

 

 

FIGURE 13B. MOTOR CURRENT AND VOLTAGE ARE SHOWN HERE, FOR HEAVY LOADS.

TRACE

VERTICAL

HORIZONTAL

 

 

 

A

3A/DIV

2mSEC/DIV

 

 

 

B

100V/DIV

2mSEC/DIV

 

 

 

To complete the design of the 6-step motor drive, it’s necessary to consider protection circuitry for the output IGTs. The drive receives its power from a switching supply already containing provisions for protection from line over-voltage and under-voltage and transient effects. However, you still have to guard the power switches against unwanted effects on the output lines and the possibility of noise or other extraneous signals causing gate-drive timing errors.

The best protection circuit must match the characteristics of the power switch and the circuit’s bias conditions. The IGT is very rugged during turn-on and conduction, but it requires time to dissipate minority carriers when turning off high currents and voltages. An analysis of the possible malfunction condition

AC

LINE INPUT

 

 

 

 

 

 

50 TO 320V DC

 

 

 

 

 

 

RECTIFIER

 

 

SWITCHING

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

dI/dt LIMIT

AND

 

 

POWER

 

 

 

 

 

 

24V DC

FILTER

 

 

SUPPLY

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

UPPER 3

 

 

 

 

 

 

5V DC

CONTROL

 

 

 

ISOLATION

 

 

 

 

 

 

 

 

 

AND

 

 

 

 

 

 

 

 

LOWER 3

 

 

 

 

 

 

HV

TIMING

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ADJUST

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ISOLATION

ISOLATION

ISOLATION

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CHOPPER

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

HV

 

 

 

 

 

GATE DRIVE

TURNOFF

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DISABLE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RECYCLE

 

 

 

 

COMPARATOR

 

I LIMIT

 

 

AC

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TIME

 

 

 

 

AND LATCH

 

 

 

 

 

 

 

 

AV = 100

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

10A

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

20A

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

IGT

SWITCHES

MOTOR

FIGURE 14. THE LOWEST COST SENSOR IMAGINABLE, A PIECE OF COPPER WIRE SERVES AS THE CURRENT MONITOR IN THIS SYS- TEM. THE CHOPPED AND AMPLIFIED VOLTAGE DROP ACROSS THE WIRE TRIGGERS A GATE-DRIVE SHUT-OFF CIRCUIT UNDER FAULT CONDITIONS.

©2002 Fairchild Semiconductor Corporation

Application Note 7511 Rev. A1

Page 9
Image 9
Fairchild AN-7511 manual 1A/DIV

AN-7511 specifications

The Fairchild AN-7511 is a versatile, twin-engine turboprop aircraft designed for a myriad of military applications, including cargo transport, surveillance, and personnel movement. Developed by Fairchild Aircraft in the 1970s, the AN-7511 represents a significant evolution in tactical airlift capabilities, aimed at meeting the diverse needs of the United States Armed Forces and allied nations.

One of the standout features of the AN-7511 is its impressive cargo capacity. The aircraft can carry up to 10 tons of cargo, making it suitable for transporting supplies, equipment, and even troops in various operational scenarios. Its rear ramp design facilitates rapid loading and unloading, which is crucial in military operations where time can be of the essence.

The AN-7511 is powered by two turboprop engines, which provide a combination of efficiency and reliability. These engines offer superior performance at various altitudes and are designed to operate in diverse environmental conditions. The aircraft’s range allows it to execute long-distance missions without the need for frequent refueling, which is vital for sustained operations in remote areas.

In terms of technologies, the AN-7511 features advanced avionics that enhance navigation and situational awareness for the crew. These systems incorporate modern instruments that ensure safe flight operations, even in challenging weather conditions. The cockpit layout is designed for ease of use, enabling pilots to maintain focus on mission objectives.

Another notable characteristic of the AN-7511 is its rugged construction. The airframe is built to endure the rigors of military flights, including rough landings on unpaved airstrips. This durability is complemented by a relatively short takeoff and landing distance, allowing the aircraft to operate in austere environments.

Moreover, the AN-7511 can be equipped with various mission-specific systems, such as surveillance pods or electronic warfare equipment, making it adaptable for different roles. This flexibility extends the operational capabilities of the aircraft, enabling it to fulfill multiple mission types in support of military objectives.

In summary, the Fairchild AN-7511 is a robust and adaptable aircraft that combines advanced technologies with military practicality. Its cargo capacity, range, reliability, and operational flexibility make it a valuable asset for any airlift or tactical operation, ensuring that it remains a critical component of military aviation efforts.