APPLIED
POWER
SYSTEMS,
INC.
124 Charlotte Avenue • Hicksville, NY 11801 • Ph: 516.935.2230 • Fax: 516.935.2603 •Website: www.applie dps.com
Page 1 of 6
Rev. 07-27-06
CAP6678
SixPac™ Series of SCR AC Controller and DC Converters
Complete Series of SCR Three-Phase Power Control Units
Features Include:
¾ Compact, rugged construction
¾ Applications include:
Windmill Converters
Motor Starters
Motor Drives
Phase Control AC
Regulated DC Power
Supplies
¾ Variable Output Voltage
¾ Output Ratings:
AC to 500Arms
DC to 600ADC
¾ 10 to 750VAC Input Voltage
¾ 40HZ to 80Hz Input Tracking with No
Tuning
¾ Includes:
Filter Capacitor Bank
Input Fusing
Laminated Bus
Snubber Board
Current Sense
Forced Air Cooling
The APS SixPac™ Series of power controllers are built
on a rugged, compact, all-inclusive, economical base.
They have a great deal of flexibility to provide OEMs
with a fully functional set of power stages. They have
been designed for long life in heavy-duty industrial
applications. The SixPac™ includes three dual isolated
SCR modules that can be configured as either a three-
phase AC Controller (AC in, phase-controlled AC out)
or a regulated DC Converter (AC in, regulated DC out).
This versatile power stage can be applied to virtually
any power application that needs phase controlled AC
or regulated DC and includes solid-state motor starters,
soft-start/soft-stop, variable speed drives, windmill
alternator converters and regulated power supplies to
name a few.
The isolated SCR modules are mounted on a high
efficiency heatsink with input fusing, forced air cooling,
and a capacitor filter bank (for regulated DC output). A
snubber for the SCRs is available if dv/dt limiting is
required. The compact design of our standard system
measures approximately 18” wide by 10” long by 11”
high, including the cooling fan, fuses, Hall effect
transducer, output bus, snubber board, SCR gate
drive board, capacitor bank, etc.
The SixPac™ is available with input from 10VAC to
700VAC, input frequencies from 40 Hz to 80Hz without
tuning (this means that input from variable frequency
alternators is acceptable as long as the frequency is
within limits). AC Controller output currents range
from 50ARMS to over 500ARMS. Regulated Converter
outputs range from 100ADC to over 600ADC.
All units come with our industry proven BAP1950
SCR Gate Firing Board. The BAP1950 board is a
flexible three-phase SCR controller suited for
industrial/commercial power supplies of any power
level. It utilizes advanced FPGA control logic to
increase reliability, circuit flexibility and reduce circuit
component count. The BAP1950 is designed to keep
the programmed delay angle constant over a wide
input frequency range (40Hz to 80Hz). This universal
input feature does not require tuning in applications
APPLIED
POWER
SYSTEMS,
INC. CAP6678
124 Charlotte Avenue • Hicksville, NY 11801 • Ph: 516.935.2230 • Fax: 516.935.2603 •Website: www.applie dps.com
where the input mains frequency may vary, as in motor
generator sets, windmill power generating equipment,
and all field generating systems. The three-phase
mains input is filtered by a unique signaling processing
circuit that is not sensitive to harmonic distortion, input
voltage amplitude fluctuations, frequency variations
or phase sequence.
♦♦♦♦
The SixPac™ configured as an AC-DC Converter, as in Figure 1, has the following features
Phase Reference Sensing & Frequency Tracking
An on board low pass filter is used to greatly reduce the
harmonic content of the mains input used to generate
the reference signals. The low pass filter attenuates the
fifth harmonics above 60Hz, reducing delay angle errors
from input line distortion. Additional circuitry actively
forces the programmed delay angle to remain invariant
over a mains input frequency from 40Hz to 80Hz.
Therefore, operation of the SixPac™ in applications
where frequency fluctuations occur regularly, i.e. when
running from an alternator input powered by a diesel,
gasoline or turbine engine; or when running from a
system with an un-stabilized frequency is permissible.
The programmed delay angle will remain constant over
the frequency range from 40Hz to 80Hz with an
accuracy of ±0.25º.
Closed Loop Voltage Regulation
The SixPac™, when supplied as a DC Converter, is
equipped with circuitry to provide a regulated DC
output, with adjustable voltage and current limits. The
output is determined by a voltage reference that can be
obtained from either an off board reference, the on
board pot or an off board pot. The voltage reference is
compared via an error amplifier to output voltage
feedback that is processed through an isolation
amplifier. Current feedback is brought back to the
board via a connector (J11) that interfaces with an
industry standard Hall Effect current transducer. An
example of such an application is shown in Figure 1.
Consult factory for output voltage scaling and error
amplifier compensation networks to obtain the desired
transient response and stability.
Soft-Start /Stop
This circuit overrides the gate delay angle command. It
is enabled by the power-on-reset feature or by contact
closure inputs. SCR gating begins at the maximum
delay angle limit and ramps down to the commanded
delay angle at a rate determined by the soft-start time
constant. The Soft-Stop feature, when activated by a
contact closure, causes the SCR gate delay angle to
ramp up from the command angle to the maximum
delay angle limit before SCR gating is inhibited.
Fast Turn-off
SCR gating is quickly enabled or inhibited (~20µSec)
on contact closure input.
Phase Loss Inhibit
The phase loss circuit inhibits the SCR gate drive if a
loss of phase voltage is detected. When voltage is
restored, the soft-start circuit is engaged.
Overtemperature Inhibit
SCR gating is instantaneously inhibited in an over
temperature condition.
Gate Delay Transfer Function
The gate delay is determined by a phase locked loop
consisting of a summing junction, low pass filter,
voltage-controlled oscillator and an application
specific integrated circuit. The voltage-controlled
oscillator frequency is locked to the mains frequency.
The DC control voltage is inserted into the summing
junction to set the SCR delay angle.
The SCR gate delay angle is controlled by an input
signal between 0 and +5 VDC. Gate delay angle is
inversely proportional to this input signal. Minimum
and maximum delay angles are determined for a
given application and the proper offset resistor is
selected from the provided resistor network.
DC Gate Drive
The SixPac™ drives each SCR with direct current.
The firing signal is an initial 2Amp pulse with a
500mA current for the duration of the conduction
angle. The open circuit voltage is 24 Volts DC. This
gate drive is suitable for driving large area SCRs in
high di/dt applications.
Remote Voltage Control
The output voltage of the power supply can be
controlled remotely with an external pot (the minimum
pot used in this application should be a 1K) or a 0 to
5V signal. This connector can be replaced with an on
board 10K pot to control the power supply output
voltage. The 5V reference at J10-1 has a limited
Page 2 of 6
Rev. 07-27-06
APPLIED
POWER
SYSTEMS,
INC. CAP6678
124 Charlotte Avenue • Hicksville, NY 11801 • Ph: 516.935.2230 • Fax: 516.935.2603 •Website: www.applie dps.com
source capability of 10 mA. Therefore, it should not be
used for any circuitry other than the pot.
J10 Connector
Pin Signal Name Description
1 5V Reference Precision 5V reference
created on board used to
control output voltage; limited
to 10 mA. Connected to the
high side of the pot.
2 Pot Wiper Connected to the wiper of an
external pot. This pin can
also be driven by a remote
voltage source referenced to
pin 3, where 0V is 0V on the
output and 5V is the full-scale
output.
3 GND GND; Connected to the low
side of the pot
Current Limit Control
The DC output of the power supply is brought back to
the board via J6. An isolation amplifier attenuates
the high voltage and isolates it from the output so that
the feedback can be referenced to the signal ground.
J8 Connector
Pin Signal
Name
Description
1 High Side To external high side of pot
2 Pot Wiper To external pot wiper (10kΩ)
3 GND To external pot low side
TB1 Connector Customer Interface for an AC to DC Conv erter AC to AC Controller Applications
Figure 1: SixPac™ as an AC to DC Converter with regulation (voltage and current feedback)
J2 J1
J3
J11
J6
Customer Control
Interface
Hall Effect
Current
Sensor
LOAD
AP1950
BAP1950
Page 3 of 6
Rev. 07-27-06
APPLIED
POWER
SYSTEMS,
INC. CAP6678
124 Charlotte Avenue • Hicksville, NY 11801 • Ph: 516.935.2230 • Fax: 516.935.2603 •Website: www.applie dps.com
Pin Pin Function Description
1 120V/208V AC From J4 on BAP1950 board
2 120V/208V AC From J4 on BAP1950 board
3 N/C Not Used
4 Fast Turn-off Shorting this pin to pin 10 enables the power supply. Letting this pin float will disable
the power supply within 20µSec.
5 Soft Start/Stop
When opened from GND (pin 6 or 9), the delay angle ramps down from maximum to
the preprogrammed value. If supply is running when the pin is shorted (to pin 6 or
9), the delay angle ramps up from the programmed value to the maximum value.
6 GND Reference forBAP1950 control circuitry including delay angle control, therefore it
must be tied to reference for delay angle control
7 Inhibit Enunciate Normally low through a 1k resistor. Transitions high in a Fast turn off or in an out of
phase lock condition.
8 Delay Angle Control
0 to 5 V analog input to control delay angle, when operating in OPEN LOOP mode.
0V → Max Delay Angle; 5V→ Min Delay Angle
9 GND Reference for BAP1950 control circuitry including delay angle control, therefore it
must be tied to reference for delay angle control
10 +5V DC Up to 50mA for customer use
AP1950
J2 J1
J3
Customer
Control
Interface
BAP1950
Figure 2: SixPac™ as an AC Controller.
Page 4 of 6
Rev. 07-27-06
CAP6678
APPLIED
POWER
SYSTEMS,
INC.
124 Charlotte Avenue • Hicksville, NY 11801 • Ph: 516.935.2230 • Fax: 516.935.2603 •Website: www.applie dps.com
Page 5 of 6
Rev. 07-27-06
Figure 3: Mechanical configuration for the DC Converter rated at 400A output at 40°C ambient.
APPLIED
POWER
SYSTEMS,
INC. CAP6678
124 Charlotte Avenue • Hicksville, NY 11801 • Ph: 516.935.2230 • Fax: 516.935.2603 •Website: www.applie dps.com
Output Current Ratings
AC Controller DC Converter
SixPac™ Size Load (Amps) Fuse Rating Load (Amps) Fuse Rating
60 50 60 100 100
90 75 90 150 150
150 150 175 300 300
250 300 350 400 400
SixPac™ Part Numbering System
CAP-6678 – XX – XXX - XXX
Code Input AC Voltage
3 digit number of input ACRMS voltage
Code Load Current
3 digit number – 050 to 400
Code Output Configuration
AC AC Output
DC DC Output
Page 6 of 6
Rev. 07-27-06
