AS440 is a half wave phase controlled thyristor type AVR and forms part of the excitation system for a brushless generator. The design employs Surface Mount Technology (SMT) for high integration of features in a small footprint AVR.
Positive voltage build up from residual levels is ensured by the use of efficient semiconductors in the power circuitry of the AVR. The power and voltage sensing circuits have separate terminals, allowing the excitation power to be derived directly from the stator winding for basic applications or from an auxiliary winding if sustained short circuit performance is required.
The AVR is linked with the main stator windings and the exciter field windings to provide closed loop control of the output voltage with load regulation of +/- 1.0%.
The AVR voltage sensing terminals continuously sample the output windings for voltage control purposes. In response to this sample voltage, the AVR controls the power fed to the exciter field, and hence the main field, to maintain the machine output voltage within the specified limits, compensating for load, speed, temperature and power factor, of the generator.
Over excitation conditions are limited to a safe period by a protection circuit within the AVR.

Provision is made for the connection of a remote voltage trimmer, allowing the user fine control of the generator's output.

An analogue input is provided allowing connection to a Newage Power Factor controller or other external devices with compatible output.

The AVR has the facility for droop CT connection, to allow parallel running with other similarly equipped generators.

Technical specification
SENSING INPUT
Voltage Jumper selectable
100-130 Vac 1 phase or
190-264 Vac 1 phase
Frequency 50-60 Hz nominal

POWER INPUT
Voltage 100-264 V ac 1 phase
Frequency 50-60 Hz nominal

OUTPUT
Voltage 82 V d. C. @ 200 V a. C.
Current continuous 4A (see note 1).
Transient 7.5A for 10 secs.
Resistance 15 ohms min
(10 ohms min when input volts is less than 175 ac)
REGULATION
+/- 1.0% (see note 2)
THERMAL DRIFT
0.03% per deg. C change in AVR ambient (see note 3)
TYPICAL SYSTEM RESPONSE
AVR response: 20 ms
Filed current to 90%: 80 ms
Machine Volts to 97%: 300 ms
EXTERNAL VOLTAGE ADJUSTMENT
+/-10% with 1 k ohm 1 watt trimmer (see note 4)
Increasing resistance lowers voltage.
UNDER FREQUENCY PROTECTION
Set point: 94 -98% Hz (see note 5)
UNIT POWER DISSIPATION
12 watts maximum
BUILD UP VOLTAGE
4 Volts @ AVR terminals
ANALOGUE INPUT
Maximum input: +/- 5 Vdc (see note 6)
Sensitivity: 1V for 5% Generator Volts (adjustable)
Input resistance 1k ohm
QUADRATURE DROOP INPUT
10 ohms burden
Max. Sensitivity: 0.07 A for 5% droop 0PF
Max. Input: 0.33 A
OVER EXCITATION PROTECTION
Set point 75 V dc
Time delay 10-15 seconds (fixed)
ENVIRONMENTAL
Vibration: 20-100 Hz 50mm/sec
100Hz -2kHz 3.3g
Operating temperature: -40 to +70º C (note 7)
Relative Humidity: 0-70º C 95% (note 8)
Storage temperature: -55 to +80º C