SL2KW SERIES MANUAL
18
118088-001 REV C
ASSEMBLY TITLE
ASSEMBLY DRAWING NO.
SCHEMATIC DRAWING NO.
J5
J5
SL Chassis (2000W)
403920-003
Control / Power PWB (2000W)
404581-001
440687-001
High Voltage Assy (2000W)
403931-TAB
440534-001
Front Panel PWB
403895-001
440525-001
Table 4.1-List of Main Assemblies
In general, the following variations can be ordered:
208Vac
10%, 50 to 60Hz, three phase.
220Vac
10%, 50 to 60Hz, single phase.
If the user is unsure of which input voltage option is
supplied, check the serial tag on the rear of the power
supply or consult Spellman’s Sales Department.
Circuit protection is provided by a front panel circuit
breaker. The circuit breaker is a fast acting magnetic trip
type circuit breaker. The line input is connected directly
to the line side of the circuit breaker whereas the load side
is connected to the CONTROL/POWER PWB. The load
side of the breaker is also connected to a step-down type
line transformer. This transformer provides voltage for
housekeeping and control circuit power.
LINE VOLTAGE IS PRESENT WHENEVER THE
POWER SUPPLY IS CONNECTED TO EXTERNAL
LINE VOLTAGES. BE SURE TO DISCONNECT
THE LINE CORD BEFORE OPENING THE UNIT.
ALLOW 5 MINUTES FOR INTERNAL
CAPACITANCE TO DISCHARGE BEFORE
REMOVING ANY COVER.
When the circuit breaker is ON, voltage is applied to an
isolated diode rectifier bridge, which contains the rectifier
diodes used for line voltage rectification. The output of
this bridge rectifier is connected to a capacitor filter.
Capacitors are initially charged through resistive inrush
limiters.
Approximately 3 seconds after the circuit breaker is
turned on, a relay is energized to short the resistor
limiters. This DC voltage is supplied to the high
frequency inverter.
The DC rails are connected to the high frequency rail
capacitors. These capacitors are high frequency, low loss
type, which provides the energy storage for the high
frequency inverter.
4.3 Inverter
The inverter is a series resonant, series/parallel loaded
topology. A proprietary control scheme is used for
regulating the power generated from the inverter. The
switching devices are IGBT’s. These devices provide
high frequency switching to control the resonant current
flow. The typical resonant operating period is
approximately 10
Seconds. The gate control for the
switching devices is provided by the application circuitry
located on the CONTROL/POWER PWB. The
CONTROL/POWER PWB also provides circuitry for
sensing shoot thru and overcurrent conditions in the
inverter.
4.4 High Voltage Transformer
The output of the High Frequency Resonant Inverter is
connected to the primary of the High Voltage
Transformer. The High Voltage Transformer is a set up
type. Typical secondary voltages are in the range of 1kV
to 4.5kV depending upon the output voltage ratings.
4.5 High Voltage Assembly
The High Voltage Assembly will vary depending upon
the model ordered. The circuitry typically consists of a
full wave, full bridge, or full wave doubler for voltage
outputs in the range of 1kV to 8kV. The higher voltage
ranges utilize various parallel, series arrangements of a
full wave voltage doubler.
Output filtering is typically provided by an R-C type
filter. Voltage feedback for regulation and monitoring is
provided by a high bandwidth resistive/capacitive divider.
Current feedback for regulation and monitoring is
provided by a sense resistor connected at the low voltage
end of the High Voltage Rectifier/Multiplier Circuit.
WARNING
